Is social distancing effective at slowing the spread of viruses?

Submitted by: PBarrett 93

Yes. The vast majority of studies in this list came to this conclusion.
NOTE: New research on COVID-19 comes out nearly every day. The state of our knowledge may change quickly so take this answer with a grain of salt.
This short answer was generated by aggregating the answers that each of the 16 studies below gave to the question (as indicated by State of K members) and adjusting for source quality and other factors. If key studies are missing or the answers attributed to individual studies are incorrect, the above answer could be wrong. For medical questions, don't rely on the information here. Consult a medical professional.


Chart summary of 16 studies examining this question
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Literature Reviews
Although we recommend you consider all of the studies below, we believe the following study is a literature review, which surveys and evaluates many studies on this question:
Additional Recommended Studies Not in this List (yet)

QUESTIONS TO CONSIDER
Are cloth masks as effective as surgical masks at reducing the risk of contracting viruses that cause respiratory disease?
6 studies
Submitted by: MChoi 148

Do adults get sick from COVID-19 more often than children?
10 studies
Submitted by: JLjilijana 85

Do cloth masks reduce the risk of contracting viruses that cause respiratory disease?
5 studies
Submitted by: JAloni 111

Does air pollution accelerate the spread of COVID-19?
5 studies
Submitted by: JLjilijana 85

Does air pollution increase the severity of symptoms from COVID-19?
6 studies
Submitted by: KKrista 83

Does an N95 mask reduce the risk of contracting viruses that cause respiratory disease better than a surgical mask?
17 studies
Submitted by: ELee 65

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SUMMARIES OF STUDIES
Total studies in list: 16
Sorted by publication year
1
Age-structured impact of social distancing on the COVID-19 epidemic in India
"The outbreak of the novel coronavirus, COVID-19, has been declared a pandemic by the WHO. The structures of social contact critically determine the spread of the infection and, in the absence of vaccines, the control of these structures through large-scale social distancing measures appears to be the most effective means of mitigation. Here we use an age-structured SIR model with social contact matrices obtained from surveys and Bayesian imputation to study the progress of the COVID-19 epidemic in India. The basic reproductive ratio R0 and its time-dependent generalization are computed based on case data, age distribution and social contact structure. The impact of social distancing measures - workplace non-attendance, school closure, lockdown - and their efficacy with durations are then investigated. A three-week lockdown is found insufficient to prevent a resurgence and, instead, protocols of sustained lockdown with periodic relaxation are suggested. Forecasts are provided for the reduction in age-structured morbidity and mortality as a result of these measures. Our study underlines the importance of age and social contact structures in assessing the country-specific impact of mitigatory social distancing."
AUTHORS
Rajesh Singh
R. Adhikari
PUBLISHED
2020 in arXiv
Preprint
Yes
Yes
2
Does Social Distancing Matter?
"This paper estimates and monetizes the impact of moderate social distancing on deaths due to COVID-19 in the United States. Using the Imperial College simulation model of COVID-19’s spread and mortality impacts (Ferguson et al. 2020), we project that moderate social distancing would save 1.7 million lives between March 1 and October 1, with 630,000 due to avoided overwhelming of hospital intensive care units. Using the projected age-specific reductions in death and age-varying estimates of the value of a statistical life (VSL), we find that the mortality benefits of social distancing are over $8 trillion or $60,000 per US household. About 90% of the monetized benefits are projected to accrue to people age 50 or older. Overall, the analysis suggests that social distancing initiatives and policies in response to the COVID-19 epidemic have substantial economic benefits."
AUTHORS
Michael Greenstone
Vishan Nigam
PUBLISHED
2020 in SSRN Working Paper Series
Preprint
Yes
Yes
3
Impact of non-pharmaceutical interventions (NPIs) to reduce COVID19 mortality and healthcare demand
"The global impact of COVID-19 has been profound, and the public health threat it represents is themost serious seen in a respiratory virus since the 1918 H1N1 influenza pandemic. Here we present theresults of epidemiological modelling which has informed policymaking in the UK and other countriesin recent weeks. In the absence of a COVID-19 vaccine, we assess the potential role of a number ofpublic health measures – so-called non-pharmaceutical interventions (NPIs) – aimed at reducingcontact rates in the population and thereby reducing transmission of the virus. In the results presentedhere, we apply a previously published microsimulation model to two countries: the UK (Great Britainspecifically) and the US. We conclude that the effectiveness of any one intervention in isolation is likelyto be limited, requiring multiple interventions to be combined to have a substantial impact ontransmission.Two fundamental strategies are possible: (a) mitigation, which focuses on slowing but not necessarilystopping epidemic spread – reducing peak healthcare demand while protecting those most at risk ofsevere disease from infection, and (b) suppression, which aims to reverse epidemic growth, reducingcase numbers to low levels and maintaining that situation indefinitely. Each policy has majorchallenges. We find that that optimal mitigation policies (combining home isolation of suspect cases,home quarantine of those living in the same household as suspect cases, and social distancing of theelderly and others at most risk of severe disease) might reduce peak healthcare demand by 2/3 anddeaths by half. However, the resulting mitigated epidemic would still likely result in hundreds ofthousands of deaths and health systems (most notably intensive care units) being overwhelmed manytimes over. For countries able to achieve it, this leaves suppression as the preferred policy option. We show that in the UK and US context, suppression will minimally require a combination of socialdistancing of the entire population, home isolation of cases and household quarantine of their familymembers. This may need to be supplemented by school and university closures, though it should berecognised that such closures may have negative impacts on health systems due to increased absenteeism. The major challenge of suppression is that this type of intensive intervention package –or something equivalently effective at reducing transmission – will need to be maintained until avaccine becomes available (potentially 18 months or more) – given that we predict that transmissionwill quickly rebound if interventions are relaxed. We show that intermittent social distancing –triggered by trends in disease surveillance – may allow interventions to be relaxed temporarily inrelative short time windows, but measures will need to be reintroduced if or when case numbersrebound. Last, while experience in China and now South Korea show that suppression is possible inthe short term"
AUTHORS
Daniel Laydon
Kylie Ainslie
Marc Baguelin
Natsuko Imai
Gemma Nedjati-Gilani,
Neil M Ferguson
PUBLISHED
2020 in Imperial College
Yes
Yes
4
The impact of social distancing and epicenter lockdown on the COVID-19 epidemic in mainland China: A data-driven SEIQR model study
"The outbreak of coronavirus disease 2019 (COVID-19) which originated in Wuhan, China, constitutes a public health emergency of international concern with a very high risk of spread and impact at the global level. We developed data-driven susceptible-exposed-infectious-quarantine-recovered (SEIQR) models to simulate the epidemic with the interventions of social distancing and epicenter lockdown. Population migration data combined with officially reported data were used to estimate model parameters, and then calculated the daily exported infected individuals by estimating the daily infected ratio and daily susceptible population size. As of Jan 01, 2020, the estimated initial number of latently infected individuals was 380.1 (95%-CI: 379.8~381.0). With 30 days of substantial social distancing, the reproductive number in Wuhan and Hubei was reduced from 2.2 (95%-CI: 1.4~3.9) to 1.58 (95%-CI: 1.34~2.07), and in other provinces from 2.56 (95%-CI: 2.43~2.63) to 1.65 (95%-CI: 1.56~1.76). We found that earlier intervention of social distancing could significantly limit the epidemic in mainland China. The number of infections could be reduced up to 98.9%, and the number of deaths could be reduced by up to 99.3% as of Feb 23, 2020. However, earlier epicenter lockdown would partially neutralize this favorable effect. Because it would cause in situ deteriorating, which overwhelms the improvement out of the epicenter. To minimize the epidemic size and death, stepwise implementation of social distancing in the epicenter city first, then in the province, and later the whole nation without the epicenter lockdown would be practical and cost-effective."
AUTHORS
Yanyun Tao
Yuzhen Zhang
Bin Jiang
Jiamin Yuang
PUBLISHED
2020 in medRxiv
Preprint
Yes
Yes
5
Estimating the reproductive number and the outbreak size of Novel Coronavirus disease (COVID-19) using mathematical model in Republic of Korea
"OBJECTIVES:Since the first novel coronavirus disease(COVID-19) patient was diagnosed on 20-Jan, about 30 patients were diagnosed in Korea until 17-Feb. However, 5,298 more patient were confirmed until 4-Mar. The purpose is to estimate and evaluate the effectiveness of preventive measures using mathematical modeling.METHODS:Deterministic mathematical model(SEIHR) has been established to suit the Korean outbreak. The number of confirmed patients in Daegu and North Gyeongsang Province(Daegu/NGP), the main area of outbreak, were used. The first patient's symptom onset date was assumed on 22-Jan. We estimate the reproduction number(R), and the effect of preventive measures, assuming that the effect has been shown from 29-Feb. or 5-Mar.RESULTS:The estimated R in Hubei Province was 4.2655, while the estimated initial R in Korea was 0.5555, but later in Daegu/NGP, the value was between 3.4721 and 3.5428. When the transmission period decreases from 4 days to 2 days, the outbreak finished early, but the peak of the epidemic has increased, and the total number of patients has not changed much. If transmission rate decreases about 90% or 99%, the outbreak finished early, and the size of the peak and the total number of patients also decreased.CONCLUSION:To early end of the COVID-19 epidemic, efforts to reduce the spread of the virus such as social distancing and mask wearing are absolutely crucial with the participation of the public, along with the policy of reducing the transmission period by finding and isolating patients as quickly as possible through efforts by the quarantine authorities."
AUTHORS
Choi SC
Ki M
PUBLISHED
2020 in Epidemiology and health
Q2
Yes
Yes
6
Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings—Social Distancing Measures
"Influenza virus infections are believed to spread mostly by close contact in the community. Social distancing measures are essential components of the public health response to influenza pandemics. The objective of these mitigation measures is to reduce transmission, thereby delaying the epidemic peak, reducing the size of the epidemic peak, and spreading cases over a longer time to relieve pressure on the healthcare system. We conducted systematic reviews of the evidence base for effectiveness of multiple mitigation measures: isolating ill persons, contact tracing, quarantining exposed persons, school closures, workplace measures/closures, and avoiding crowding. Evidence supporting the effectiveness of these measures was obtained largely from observational studies and simulation studies. Voluntary isolation at home might be a more feasible social distancing measure, and pandemic plans should consider how to facilitate this measure. More drastic social distancing measures might be reserved for severe pandemics."
AUTHORS
Jessica Y. Wong
Sukhyun Ryu
Eunice Y.C. Shiu
Min W. Fong
Huizhi Gao
Jingyi Xiao et al
PUBLISHED
2020 in Emerging Infectious Diseases
High quality source
Literature Review
Yes
Yes
7
Individual preventive social distancing during an epidemic may have negative population-level outcomes.
"The outbreak of an infectious disease in a human population can lead to individuals responding with preventive measures in an attempt to avoid getting infected. This leads to changes in contact patterns. However, as we show in this paper, rational behaviour at the individual level, such as social distancing from infectious contacts, may not always be beneficial for the population as a whole. We use epidemic network models to demonstrate the potential negative consequences at the population level. We take into account the social structure of the population through several network models. As the epidemic evolves, susceptible individuals may distance themselves from their infectious contacts. Some individuals replace their lost social connections by seeking new ties. If social distancing occurs at a high rate at the beginning of an epidemic, then this can prevent an outbreak from occurring. However, we show that moderate social distancing can worsen the disease outcome, both in the initial phase of an outbreak and the final epidemic size. Moreover, the same negative effect can arise in real-world networks. Our results suggest that one needs to be careful when targeting behavioural changes as they could potentially "
AUTHORS
Tom Britton
Frank Ball
David Sirl
Ka Yin Leung
PUBLISHED
2018 in Journal of the Royal Society, Interface
High quality source
No
No
8
Effectiveness of workplace social distancing measures in reducing influenza transmission: a systematic review.
"Background: Social distancing is one of the community mitigation measures that may be recommended during influenza pandemics. Social distancing can reduce virus transmission by increasing physical distance or reducing frequency of congregation in socially dense community settings, such as schools or workplaces. We conducted a systematic review to assess the evidence that social distancing in non-healthcare workplaces reduces or slows influenza transmission.Methods: Electronic searches were conducted using MEDLINE, Embase, Scopus, Cochrane Library, PsycINFO, CINAHL, NIOSHTIC-2, and EconLit to identify studies published in English from January 1, 2000, through May 3, 2017. Data extraction was done by two reviewers independently. A narrative synthesis was performed.Results: Fifteen studies, representing 12 modeling and three epidemiological, met the eligibility criteria. The epidemiological studies showed that social distancing was associated with a reduction in influenza-like illness and seroconversion to 2009 influenza A (H1N1). However, the overall risk of bias in the epidemiological studies was serious. The modeling studies estimated that workplace social distancing measures alone produced a median reduction of 23% in the cumulative influenza attack rate in the general population. It also delayed and reduced the peak influenza attack rate. The reduction in the cumulative attack rate was more pronounced when workplace social distancing was combined with other nonpharmaceutical or pharmaceutical interventions. However, the effectiveness was estimated to decline with higher basic reproduction number values, delayed triggering of workplace social distancing, or lower compliance.Conclusions: Modeling studies support social distancing in non-healthcare workplaces, but there is a paucity of well-designed epidemiological studies.Systematic Review Registration Number: PROSPERO registration # CRD42017065310."
AUTHORS
Nicole Zviedrite
Amra Uzicanin
Faruque Ahmed
PUBLISHED
2018 in BMC public health
High quality source
Yes
Yes
9
AUTHORS
James G. Wood
Hatice Tekin
Matthew Begun
Iman Ridda
Catherine King
Harunor Rashid et al
PUBLISHED
2015 in Paediatric Respiratory Reviews
Q2
Yes
Yes
10
Spontaneous social distancing in response to a simulated epidemic: a virtual experiment.
"Background: Studies of social distancing during epidemics have found that the strength of the response can have a decisive impact on the outcome. In previous work we developed a model of social distancing driven by individuals' risk attitude, a parameter which determines the extent to which social contacts are reduced in response to a given infection level. We showed by simulation that a strong response, driven by a highly cautious risk attitude, can quickly suppress an epidemic. However, a moderately cautious risk attitude gives weak control and, by prolonging the epidemic without reducing its impact, may yield a worse outcome than doing nothing. In real societies, social distancing may arise spontaneously from individual choices rather than being imposed centrally. There is little data available about this as opportunistic data collection during epidemics is difficult. Our study uses a simulated epidemic in a computer game setting to measure the social distancing response.Methods: Two hundred thirty participants played a computer game simulating an epidemic on a spatial network. The player controls one individual in a population of 2500 (with others controlled by computer) and decides how many others to contact each day. To mimic real-world trade-offs, the player is motivated to make contact by being rewarded with points, while simultaneously being deterred by the threat of infection. Participants completed a questionnaire regarding psychological measures of health protection motivation. Finally, simulations were used to compare the experimentally-observed response to epidemics with no response.Results: Participants reduced contacts in response to infection in a manner consistent with our model of social distancing. The experimentally observed response was too weak to halt epidemics quickly, resulting in a somewhat reduced attack rate and a substantially reduced peak attack rate, but longer duration and fewer social contacts, compared to no response. Little correlation was observed between participants' risk attitudes and the psychological measures.Conclusions: Our cognitive model of social distancing matches responses to a simulated epidemic. If these responses indicate real world behaviour, spontaneous social distancing can be expected to reduce peak attack rates. However, additional measures are needed if it is important to stop an epidemic quickly."
AUTHORS
Susan Rasmussen
Savi Maharaj
Nicole Cairns
Lynn Williams
Adam Kleczkowski
PUBLISHED
2015 in BMC public health
High quality source
Yes
Yes
11
AUTHORS
William D. Wheaton
Philip C. Cooley
Diane K. Wagener
Sarah M. Bartsch
Bruce Y. Lee
Shawn T. Brown
PUBLISHED
2015 in Computational and Mathematical Organization Theory
Q2
FUNDERS
National Institute of General Medical Sciences
Yes
Yes
12
AUTHORS
L. A. Braunstein
P. A. Macri
L. D. Valdez
C. Buono
PUBLISHED
2014 in Perspectives and Challenges in Statistical Physics and Complex Systems for the Next Decade
Yes
Yes
13
Non-pharmaceutical interventions for the prevention of respiratory tract infections during Hajj pilgrimage
"Overcrowding during the yearly Hajj mass gatherings is associated with increased risk of spreading infectious diseases, particularly respiratory diseases. Non-pharmaceutical interventions (e.g., hand hygiene, wearing face masks, social distancing) are known to reduce the spread of respiratory viruses from person to person and are therefore recommended to pilgrims by public health agencies. The implementation of effective public health policies and recommendations involves evaluating the adherence to and effectiveness of these measures in the specific context of the Hajj. This review summarizes the evidence related to the effectiveness of non-pharmaceutical interventions in preventing the spread of respiratory infectious diseases during the Hajj. Overall, although hand hygiene compliance is high among pilgrims, face mask use and social distancing remain difficult challenges. Data about the effectiveness of these measures at the Hajj are limited, and results are contradictory, highlighting the need for future large-scale studies. "
AUTHORS
Philippe Brouqui
Samir Benkouiten
Philippe Gautret
PUBLISHED
2014 in Travel Medicine and Infectious Disease
High quality source
Couldn't Identify
Couldn't Identify
14
Characterizing the epidemiology of the 2009 influenza A/H1N1 pandemic in Mexico.
"Background: Mexico's local and national authorities initiated an intense public health response during the early stages of the 2009 A/H1N1 pandemic. In this study we analyzed the epidemiological patterns of the pandemic during April-December 2009 in Mexico and evaluated the impact of nonmedical interventions, school cycles, and demographic factors on influenza transmission.Methods And Findings: We used influenza surveillance data compiled by the Mexican Institute for Social Security, representing 40% of the population, to study patterns in influenza-like illness (ILIs) hospitalizations, deaths, and case-fatality rate by pandemic wave and geographical region. We also estimated the reproduction number (R) on the basis of the growth rate of daily cases, and used a transmission model to evaluate the effectiveness of mitigation strategies initiated during the spring pandemic wave. A total of 117,626 ILI cases were identified during April-December 2009, of which 30.6% were tested for influenza, and 23.3% were positive for the influenza A/H1N1 pandemic virus. A three-wave pandemic profile was identified, with an initial wave in April-May (Mexico City area), a second wave in June-July (southeastern states), and a geographically widespread third wave in August-December. The median age of laboratory confirmed ILI cases was ∼ 18 years overall and increased to ∼ 31 years during autumn (p<0.0001). The case-fatality ratio among ILI cases was 1.2% overall, and highest (5.5%) among people over 60 years. The regional R estimates were 1.8-2.1, 1.6-1.9, and 1.2-1.3 for the spring, summer, and fall waves, respectively. We estimate that the 18-day period of mandatory school closures and other social distancing measures implemented in the greater Mexico City area was associated with a 29%-37% reduction in influenza transmission in spring 2009. In addition, an increase in R was observed in late May and early June in the southeast states, after mandatory school suspension resumed and before summer vacation started. State-specific fall pandemic waves began 2-5 weeks after school reopened for the fall term, coinciding with an age shift in influenza cases.Conclusions: We documented three spatially heterogeneous waves of the 2009 A/H1N1 pandemic virus in Mexico, which were characterized by a relatively young age distribution of cases. Our study highlights the importance of school cycles on the transmission dynamics of this pandemic influenza strain and suggests that school closure and other mitigation measures could be useful to mitigate future influenza pandemics. Please see later in the article for the Editors' Summary."
AUTHORS
Gerardo Chowell
Mark A Miller
James Tamerius
Víctor H Borja-Aburto
Lone Simonsen
Santiago Echevarría-Zuno et al
PUBLISHED
2011 in PLoS medicine
High quality source
Yes
Yes
15
AUTHORS
Peng Sun
Wen-bo Du
Cai-long Chen
Xian-bin Cao
PUBLISHED
2010 in Physics Procedia
Q0
Couldn't Identify
Couldn't Identify
16
Targeted social distancing design for pandemic influenza.
"Targeted social distancing to mitigate pandemic influenza can be designed through simulation of influenza's spread within local community social contact networks. We demonstrate this design for a stylized community representative of a small town in the United States. The critical importance of children and teenagers in transmission of influenza is first identified and targeted. For influenza as infectious as 1957-58 Asian flu (=50% infected), closing schools and keeping children and teenagers at home reduced the attack rate by >90%. For more infectious strains, or transmission that is less focused on the young, adults and the work environment must also be targeted. Tailored to specific communities across the world, such design would yield local defenses against a highly virulent strain in the absence of vaccine and antiviral drugs."
AUTHORS
H Jason Min
Walter E Beyeler
Laura M Glass
Robert J Glass
PUBLISHED
2006 in Emerging Infectious Diseases
High quality source
Yes
Yes







ADDITIONAL STUDIES TO CONSIDER ADDING TO LIST
Total additional studies: 53
State of K's algorithms generated the list of studies below based on the studies that were added to the above list. Some of these studies may also examine: "Is social distancing effective at slowing the spread of viruses?" If a study examines this question, add it to the list by pressing the button.

Only add studies that examine the same question. Do not add studies that are merely on the same topic.

Impact of self-imposed prevention measures and short-term government intervention on mitigating and delaying a COVID-19 epidemic
"Background: With new cases of COVID-19 surging around the world, many countries have to prepare for moving beyond the containment phase. Prediction of the effectiveness of non-case-based interventions for mitigating, delaying or preventing the epidemic is urgent, especially for countries affected by the ongoing seasonal influenza activity.

Methods: We developed a transmission model to evaluate the impact of self-imposed prevention measures (handwashing, mask-wearing, and social distancing) due to the spread of COVID-19 awareness and of short-term government-imposed social distancing on the peak number of diagnoses, attack rate and time until the peak number of diagnoses.

Findings: For fast awareness spread in the population, self-imposed measures can significantly reduce the attack rate, diminish and postpone the peak number of diagnoses. A large epidemic can be prevented if the efficacy of these measures exceeds 50%. For slow awareness spread, self-imposed measures reduce the peak number of diagnoses and attack rate but do not affect the timing of the peak. Early implementation of short-term government interventions can only delay the peak (by at most 7 months for a 3-month intervention).

Interpretation: Handwashing, mask-wearing and social distancing as a reaction to information dissemination about COVID-19 can be effective strategies to mitigate and delay the epidemic. We stress the importance of rapidly spreading awareness on the use of these self-imposed prevention measures in the population. Early-initiated short-term government-imposed social distancing can buy time for healthcare systems to prepare for an increasing COVID-19 burden.

Keywords: SARS-CoV-2, COVID-19, mathematical model, prevention measures, mitigation, epidemic control, disease awareness, social distancing, handwashing, mask-wearing"
AUTHORS
Martin C.J. Bootsma
Mirjam E. Kretzschmar
Thi Mui Pham
Alexandra Teslya
Noortje G. Godijk
Ganna Rozhnova
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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A hybrid multi-scale model of COVID-19 transmission dynamics to assess the potential of non-pharmaceutical interventions
"Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that emerged in Wuhan, China in December 2019. It has caused a global outbreak which represents a major threat to global health. Public health resorted to non-pharmaceutical interventions such as social distancing and lockdown to slow down the spread of the pandemic. However, the effect of each of these measures remains hard to quantify. We design a multi-scale model that simulates the transmission dynamics of COVID-19. We describe the motion of individual agents using a social force model. Each agent can be either susceptible, infected, quarantined, immunized or deceased. The model considers both mechanisms of direct and indirect transmission. We parameterize the model to reproduce the early dynamics of disease spread in Italy. We show that panic situations increase the risk of infection transmission in crowds despite social distancing measures. Next, we suggest that pre-symptomatic transmission could be a significant driver of the infection spread. Then, we show that the restricted movement of the individuals flattens the epidemic curve. Finally, model predictions suggest that measures stricter than social distancing and lockdown were used to control the epidemic in Wuhan, China."
AUTHORS
Aissam Jebrane
Anass Bouchnita
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Literature review
Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review.
"Objective: To systematically review evidence for the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses.

Data Extraction: Search strategy of the Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without language restriction, for any intervention to prevent transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection, and hygiene). Study designs were randomised trials, cohort studies, case-control studies, and controlled before and after studies.

Data Synthesis: Of 2300 titles scanned 138 full papers were retrieved, including 49 papers of 51 studies. Study quality was poor for the three randomised controlled trials and most of the cluster randomised controlled trials; the observational studies were of mixed quality. Heterogeneity precluded meta-analysis of most data except that from six case-control studies. The highest quality cluster randomised trials suggest that the spread of respiratory viruses into the community can be prevented by intervening with hygienic measures aimed at younger children. Meta-analysis of six case-control studies suggests that physical measures are highly effective in preventing the spread of SARS: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat=4, 95% confidence interval 3.65 to 5.52); wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03); wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06); wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41); wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12); and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease the spread of respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions being drawn.

Conclusion: Routine long term implementation of some physical measures to interrupt or reduce the spread of respiratory viruses might be difficult but many simple and low cost interventions could be useful in reducing the spread.

"
AUTHORS
Bill Hewak
Eliana Ferroni
Liz Dooley
Chris Del Mar
Ruth Foxlee
Tom Jefferson et al
PUBLISHED

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Literature review
Highly regarded source
Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review.
"Objective: To review systematically the evidence of effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses.

Data Sources: Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without restrictions on language or publication. Data selection Studies of any intervention to prevent the transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection, and hygiene). A search of study designs included randomised trials, cohort, case-control, crossover, before and after, and time series studies. After scanning of the titles, abstracts and full text articles as a first filter, a standardised form was used to assess the eligibility of the remainder. Risk of bias of randomised studies was assessed for generation of the allocation sequence, allocation concealment, blinding, and follow-up. Non-randomised studies were assessed for the presence of potential confounders and classified as being at low, medium, or high risk of bias.

Data Synthesis: 58 papers of 59 studies were included. The quality of the studies was poor for all four randomised controlled trials and most cluster randomised controlled trials; the observational studies were of mixed quality. Meta-analysis of six case-control studies suggested that physical measures are highly effective in preventing the spread of severe acute respiratory syndrome: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat=4, 95% confidence interval 3.65 to 5.52), wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03), wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06), wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41), wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12), and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The combination was also effective in interrupting the spread of influenza within households. The highest quality cluster randomised trials suggested that spread of respiratory viruses can be prevented by hygienic measures in younger children and within households. Evidence that the more uncomfortable and expensive N95 masks were superior to simple surgical masks was limited, but they caused skin irritation. The incremental effect of adding virucidals or antiseptics to normal handwashing to reduce respiratory disease remains uncertain. Global measures, such as screening at entry ports, were not properly evaluated. Evidence was limited for social distancing being effective, especially if related to risk of exposure-that is, the higher the risk the longer the distancing period.

Conclusion: Routine long term implementation of some of the measures to interrupt or reduce the spread of respiratory viruses might be difficult. However, many simple and low cost interventions reduce the transmission of epidemic respiratory viruses. More resources should be invested into studying which physical interventions are the most effective, flexible, and cost effective means of minimising the impact of acute respiratory tract infections."
AUTHORS
Ghada A Bawazeer
Lubna A Al-Ansary
Eliana Ferroni
Liz Dooley
Chris Del Mar
Tom Jefferson et al
PUBLISHED
2009 in BMJ : British Medical Journal

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Differences in power-law growth over time and indicators of COVID-19 pandemic progression worldwide
"An automated statistical and error analysis of 45 countries or regions with more than 1000 cases of COVID-19 as of March 28, 2020, has been performed. This study reveals differences in the rate of disease spreading rate over time in different countries. This survey observes that most countries undergo a beginning exponential growth phase, which transitions into a power-law phase, as recently suggested by Ziff and Ziff. Tracking indicators of growth, such as the power-law exponent, are a good indication of the relative danger different countries are in and show when social measures are effective towards slowing the spread. The data compiled here are usefully synthesizing a global picture, identifying country to country variation in spreading, and identifying countries most at risk. This analysis may factor into how best to track the effectiveness of social distancing policies and quarantines in real-time as data is updated each day."
AUTHOR
Jack Merrin
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Sitagliptin: a potential drug for the treatment of SARS-CoV-2?
"Recently, an outbreak of fatal coronavirus, SARS-CoV-2, has emerged from China and is rapidly spreading worldwide. As the coronavirus pandemic rages, drug discovery and development become even more challenging. Drug repurposing of the antimalarial drug chloroquine and its hydroxylated form had demonstrated apparent effectiveness in the treatment of COVID-19 associated pneumonia in clinical trials. SARS-CoV-2 spike protein shares 31.9% sequence identity with the spike protein presents in the Middle East Respiratory Syndrome Corona Virus (MERS-CoV), which infects cells through the interaction of its spike protein with the DPP4 receptor found on macrophages. Sitagliptin, a DPP4 inhibitor, that is known for its antidiabetic, immunoregulatory, anti-inflammatory, and beneficial cardiometabolic effects has been shown to reverse macrophage responses in MERS-CoV infection and reduce CXCL10 chemokine production in AIDS patients. We suggest that Sitagliptin may be beneficial alternative for the treatment of COVID-19 disease especially in diabetic patients and patients with preexisting cardiovascular conditions who are already at higher risk of COVID-19 infection."
AUTHOR
Sanaa Bardaweel
PUBLISHED
2020 in Center for Open Science

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A Genomic Survey of SARS-CoV-2 Reveals Multiple Introductions into Northern California without a Predominant Lineage
"The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 has spread globally, resulting in &gt;300,000 reported cases worldwide as of March 21st, 2020. Here we investigate the genetic diversity and genomic epidemiology of SARS-CoV-2 in Northern California using samples from returning travelers, cruise ship passengers, and cases of community transmission with unclear infection sources. Virus genomes were sampled from 29 patients diagnosed with COVID-19 infection from Feb 3rd through Mar 15th. Phylogenetic analyses revealed at least 8 different SARS-CoV-2 lineages, suggesting multiple independent introductions of the virus into the state. Virus genomes from passengers on two consecutive excursions of the Grand Princess cruise ship clustered with those from an established epidemic in Washington State, including the WA1 genome representing the first reported case in the United States on January 19th. We also detected evidence for presumptive transmission of SARS-CoV-2 lineages from one community to another. These findings suggest that cryptic transmission of SARS-CoV-2 in Northern California to date is characterized by multiple transmission chains that originate via distinct introductions from international and interstate travel, rather than widespread community transmission of a single predominant lineage. Rapid testing and contact tracing, social distancing, and travel restrictions are measures that will help to slow SARS-CoV-2 spread in California and other regions of the USA."
AUTHORS
Michael Famulare
Pavitra Roychoudhury
Trevor Bedford
Karthik Gangavarapu
Charles Y Chiu
Scot Federman et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Highly regarded source
An Analysis of 38 Pregnant Women with COVID-19, Their Newborn Infants, and Maternal-Fetal Transmission of SARS-CoV-2: Maternal Coronavirus Infections and Pregnancy Outcomes
" The emergence of a novel coronavirus, termed SARS-CoV-2, and the potentially life-threating respiratory disease that it can produce, COVID-19, has rapidly spread across the globe creating a massive public health problem. Previous epidemics of many emerging viral infections have typically resulted in poor obstetrical outcomes including maternal morbidity and mortality, maternal-fetal transmission of the virus, and perinatal infections and death. This communication reviews the effects of two previous coronavirus infections - severe acute respiratory syndrome (SARS) caused by SARS-CoV and Middle East respiratory syndrome (MERS) caused by MERS-CoV - on pregnancy outcomes. In addition, it analyzes literature describing 38 pregnant women with COVID-19 and their newborns in China to assess the effects of SARS-CoV-2 on the mothers and infants including clinical, laboratory and virologic data, and the transmissibility of the virus from mother to fetus. This analysis reveals that unlike coronavirus infections of pregnant women caused by SARS and MERS, in these 38 pregnant women COVID-19 did not lead to maternal deaths. Importantly, and similar to pregnancies with SARS and MERS, there were no confirmed cases of intrauterine transmission of SARS-CoV-2 from mothers with COVID-19 to their fetuses. All neonatal specimens tested, including in some cases placentas, were negative by rt-PCR for SARS-CoV-2. At this point in the global pandemic of COVID-19 infection there is no evidence that SARS-CoV-2 undergoes intrauterine or transplacental transmission from infected pregnant women to their fetuses. Analysis of additional cases is necessary to determine if this remains true. "
AUTHOR
David A. Schwartz
PUBLISHED
2020 in Archives of Pathology & Laboratory Medicine

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Potent Antiviral Activities of Type I Interferons to SARS-CoV-2 Infection
"The ongoing historic outbreak of COVID-19 not only constitutes a global public health crisis, but also carries a devastating social and economic impact. The disease is caused by a newly identified coronavirus, Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). There is an urgent need to identify antivirals to curtail the COVID-19 pandemic. Herein, we report the remarkable sensitivity of SARS-CoV-2 to recombinant human interferons α and β (IFNα/β). Treatment with IFN-α at a concentration of 50 international units (IU) per milliliter drastically reduces viral titers by 3.4 log or over 4 log, respectively, in Vero cells. The EC50 of IFN-α and IFN-β treatment is 1.35 IU/ml and 0.76 IU/ml, respectively, in Vero cells. These results suggest that SARS-CoV-2 is more sensitive than many other human pathogenic viruses, including SARS-CoV. Overall, our results demonstrate the potent efficacy of human Type I IFN in suppressing SARS-CoV-2 infection, a finding which could inform future treatment options for COVID-19."
AUTHORS
Cheng Huang
Slobodan Paessler
Junki Maruyama
Natalya Bukreyeva
Emily K. Mantlo
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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When Darkness Becomes a Ray of Light in the Dark Times: Understanding the COVID-19 via the Comparative Analysis of the Dark Proteomes of SARS-CoV-2, Human SARS and Bat SARS-Like Coronaviruses
"AbstractRecently emerged coronavirus designated as SARS-CoV-2 (also known as 2019 novel coronavirus (2019-nCoV) or Wuhan coronavirus) is a causative agent of coronavirus disease 2019 (COVID-19), which is rapidly spreading throughout the world now. More than 9,00,000 cases of SARS-CoV-2 infection and more than 47,000 COVID-19-associated mortalities have been reported worldwide till the writing of this article, and these numbers are increasing every passing hour. World Health Organization (WHO) has declared the SARS-CoV-2 spread as a global public health emergency and admitted that the COVID-19 is a pandemic now. The multiple sequence alignment data correlated with the already published reports on the SARS-CoV-2 evolution and indicated that this virus is closely related to the bat Severe Acute Respiratory Syndrome-like coronavirus (bat SARS-like CoV) and the well-studied Human SARS coronavirus (SARS CoV). The disordered regions in viral proteins are associated with the viral infectivity and pathogenicity. Therefore, in this study, we have exploited a set of complementary computational approaches to examine the dark proteomes of SARS-CoV-2, bat SARS-like, and human SARS CoVs by analysing the prevalence of intrinsic disorder in their proteins. According to our findings, SARS-CoV-2 proteome contains very significant levels of structural order. In fact, except for Nucleocapsid, Nsp8, and ORF6, the vast majority of SARS-CoV-2 proteins are mostly ordered proteins containing less intrinsically disordered protein regions (IDPRs). However, IDPRs found in SARS-CoV-2 proteins are functionally important. For example, cleavage sites in its replicase 1ab polyprotein are found to be highly disordered, and almost all SARS-CoV-2 proteins were shown to contain molecular recognition features (MoRFs), which are intrinsic disorder-based protein-protein interaction sites that are commonly utilized by proteins for interaction with specific partners. The results of our extensive investigation of the dark side of the SARS-CoV-2 proteome will have important implications for the structural and non-structural biology of SARS or SARS-like coronaviruses.SignificanceThe infection caused by a novel coronavirus (SARS-CoV-2) that causes severe respiratory disease with pneumonia-like symptoms in humans is responsible for the current COVID-19 pandemic. No in-depth information on structures and functions of SARS-CoV-2 proteins is currently available in the public domain, and no effective anti-viral drugs and/or vaccines are designed for the treatment of this infection. Our study provides the first comparative analysis of the order- and disorder-based features of the SARS-CoV-2 proteome relative to human SARS and bat CoV that may be useful for structure-based drug discovery."
AUTHORS
Rajanish Giri
Christopher J. Oldfield
Kundlik Gadhave
Bhuvaneshwari R. Gehi
Meenakshi Shegane
Taniya Bhardwaj et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Highly regarded source
An Analysis of 38 Pregnant Women with COVID-19, Their Newborn Infants, and Maternal-Fetal Transmission of SARS-CoV-2: Maternal Coronavirus Infections and Pregnancy Outcomes
"The emergence of a novel coronavirus, termed SARS-CoV-2, and the potentially life-threatening respiratory disease that it can produce, COVID-19, has rapidly spread across the globe creating a massive public health problem. Previous epidemics of many emerging viral infections have typically resulted in poor obstetrical outcomes including maternal morbidity and mortality, maternal-fetal transmission of the virus, and perinatal infections and death. This communication reviews the effects of two previous coronavirus infections - severe acute respiratory syndrome (SARS) caused by SARS-CoV and Middle East respiratory syndrome (MERS) caused by MERS-CoV - on pregnancy outcomes. In addition, it analyzes literature describing 38 pregnant women with COVID-19 and their newborns in China to assess the effects of SARS-CoV-2 on the mothers and infants including clinical, laboratory and virologic data, and the transmissibility of the virus from mother to fetus. This analysis reveals that unlike coronavirus infections of pregnant women caused by SARS and MERS, in these 38 pregnant women COVID-19 did not lead to maternal deaths. Importantly, and similar to pregnancies with SARS and MERS, there were no confirmed cases of intrauterine transmission of SARS-CoV-2 from mothers with COVID-19 to their fetuses. All neonatal specimens tested, including in some cases placentas, were negative by rt-PCR for SARS-CoV-2. At this point in the global pandemic of COVID-19 infection there is no evidence that SARS-CoV-2 undergoes intrauterine or transplacental transmission from infected pregnant women to their fetuses. Analysis of additional cases is necessary to determine if this remains true."
AUTHOR
Schwartz DA
PUBLISHED
2020 in Archives of Pathology & Laboratory Medicine

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Lactoferrin as potential preventative and treatment for COVID-19
"The novel coronavirus 2019 (COVID-19) pandemic is rapidly advancing across the globe despite public and personal health measures. Antivirals and nutritional supplements have been proposed as potentially useful against SARS-CoV-2 (virus that causes COVID-19), but few have been clinically established. Lactoferrin (Lf) is a naturally occurring and non-toxic glycoprotein that is orally available as a nutritional supplement and has established in vitro anti-viral efficacy against a wide range of virus including SARS-CoV, a closely related corona virus to SARS-CoV-2 (virus that causes COVID-19). Furthermore, Lf possesses unique immunomodulatory and anti-inflammatory effects that maybe especially relevant to the pathophysiology of severe COVID-19 cases. We review the underlying biological mechanisms of Lf as antiviral and immune regulator, and propose its unique potential as preventative and adjunct treatment for COVID-19. We hope that further research and development of Lf nutritional supplementation would establish its role for COVID-19."
AUTHORS
Wei-Zen Sun
Raymond Chang
Tzi Bun Ng
PUBLISHED
2020 in Center for Open Science

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A human monoclonal antibody blocking SARS-CoV-2 infection
"AbstractThe emergence of the novel human coronavirus SARS-CoV-2 in Wuhan, China has caused a worldwide epidemic of respiratory disease (COVID-19). Vaccines and targeted therapeutics for treatment of this disease are currently lacking. Here we report a human monoclonal antibody that neutralizes SARS-CoV-2 (and SARS-CoV). This cross-neutralizing antibody targets a communal epitope on these viruses and offers potential for prevention and treatment of COVID-19."
AUTHORS
Dubravka Drabek
Frank J.M. van Kuppeveld
Berend-Jan Bosch
Wentao Li
Chunyan Wang
Bart L. Haagmans et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Spontaneous social distancing in response to a simulated epidemic: a virtual experiment
You can view the abstract at: https://doi.org/10.1186/s12889-015-2336-7
AUTHORS
Nicole Cairns
Lynn Williams
Susan Rasmussen
Savi Maharaj
Adam Kleczkowski
PUBLISHED

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Protection motivation theory and social distancing behaviour in response to a simulated infectious disease epidemic
"Epidemics of respiratory infectious disease remain one of the most serious health risks facing the population. Non-pharmaceutical interventions (e.g. hand-washing or wearing face masks) can have a significant impact on the course of an infectious disease epidemic. The current study investigated whether protection motivation theory (PMT) is a useful framework for understanding social distancing behaviour (i.e. the tendency to reduce social contacts) in response to a simulated infectious disease epidemic. There were 230 participants (109 males, 121 females, mean age 32.4 years) from the general population who completed self-report measures assessing the components of PMT. In addition, participants completed a computer game which simulated an infectious disease epidemic in order to provide a measure of social distancing behaviour. The regression analyses revealed that none of the PMT variables were significant predictors of social distancing behaviour during the simulation task. However, fear (β = .218, p < .001), response efficacy (β = .175, p < .01) and self-efficacy (β = .251, p < .001) were all significant predictors of intention to engage in social distancing behaviour. Overall, the PMT variables (and demographic factors) explain 21.2% of the variance in intention. The findings demonstrated that PMT was a useful framework for understanding intention to engage in social distancing behaviour, but not actual behaviour during the simulated epidemic. These findings may reflect an intention-behaviour gap in relation to social distancing behaviour."
AUTHORS
Susan Rasmussen
Savi Maharaj
Nicole Cairns
Lynn Williams
Adam Kleczkowski
PUBLISHED
2015 in Psychology, Health & Medicine

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Spatial proximity amplifies valence in emotional memory and defensive approach-avoidance.
"In urban areas, people often have to stand or move in close proximity to others. The egocentric distance to stimuli is a powerful determinant of defensive behavior in animals. Yet, little is known about how spatial proximity to others alters defensive responses in humans. We hypothesized that the valence of social cues scales with egocentric distance, such that proximal social stimuli have more positive or negative valence than distal stimuli. This would predict enhanced defensive responses to proximal threat and reduced defensive responses to proximal reward. We tested this hypothesis across four experiments using 3-D virtual reality simulations. Results from Experiment 1 confirmed that proximal social stimuli facilitate defensive responses, as indexed by fear-potentiated startle, relative to distal stimuli. Experiment 2 revealed that interpersonal defensive boundaries flexibly increase with aversive learning. Experiment 3 examined whether spatial proximity enhances memory for aversive experiences. Fear memories for social threats encroaching on the body were more persistent than those acquired at greater interpersonal distances, as indexed by startle. Lastly, Experiment 4 examined how egocentric distance influenced startle responses to social threats during defensive approach and avoidance. Whereas fear-potentiated startle increased with proximity when participants actively avoided receiving shocks, startle decreased with proximity when participants tolerated shocks to receive monetary rewards, implicating opposing gradients of distance on threat versus reward. Thus, proximity in egocentric space amplifies the valence of social stimuli that, in turn, facilitates emotional memory and approach-avoidance responses. These findings have implications for understanding the consequences of increased urbanization on affective interpersonal behavior. "
AUTHORS
Kevin S LaBar
Fredrik Åhs
David Zielinski
Joseph E Dunsmoor
PUBLISHED
2015 in Neuropsychologia

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The virtual doppelganger: effects of a virtual reality simulator on perceptions of schizophrenia.
"Recent scholarship suggests that virtual environments can serve as effective proxies in battling implicit stereotypes. However, existing experimental research has rarely examined the effectiveness of virtual simulations of mental illnesses in inducing empathy to combat stereotypical responses. We report results from a 4-condition, between subjects experiment (N = 112), wherein participants were exposed to either a virtual simulation of schizophrenia, a written empathy-set induction of schizophrenia, a combination of both the simulation and written empathy conditions, or a control condition. The results indicated that the virtual simulation + empathy condition induced greater empathy and more positive perceptions toward people suffering from schizophrenia than the control or written empathy-set condition. Interestingly, the simulation-only condition resulted in the greatest desire for social distance whereas not significantly differing on empathy and attitude measures from either the written empathy or simulation + empathy conditions. We discuss the implications of the findings and recommend directions for future research."
AUTHORS
James D Ivory
Sriram Sri Kalyanaraman
David L Penn
Abigail Judge
PUBLISHED
2010 in The Journal of Nervous And Mental Disease

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Risk perception and effectiveness of uncoordinated behavioral responses in an emerging epidemic
"Beyond control measures imposed by public authorities, human behavioral changes can be triggered by uncoordinated responses driven by the risk perception of an emerging epidemic. In order to account for spontaneous social distancing, a model based on an evolutionary game theory framework is here proposed. Behavioral changes are modeled through an imitation process in which the convenience of different behaviors depends on the perceived prevalence of infections. Effects of misperception of risk induced by partial or incorrect information concerning the state of the epidemic are considered as well. Our findings highlight that, if the perceived risk associated to an epidemic is sufficiently large, then even a small reduction in the number of potentially infectious contacts (as a response to the epidemic) can remarkably affect the infection spread. In particular, the earlier the warning about the epidemic appears, the larger the possible reduction of the peak prevalence, and of the final epidemic size. Moreover, the epidemic spread is delayed if individuals' perception of risk is based on a memory mechanism and the risk of infection is initially overestimated. In conclusion, this analysis allows noteworthy inferences about the role of risk perception and the effectiveness of spontaneous behavioral changes during an emerging epidemic."
AUTHORS
Piero Poletti
Marco Ajelli
Stefano Merler
PUBLISHED
2012 in Mathematical Biosciences

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Homo-psychologicus: Reactionary behavioural aspects of epidemics
FUNDERS
National Science Foundation
"We formulate an in silico model of pathogen avoidance mechanism and investigate its impact on defensive behavioural measures (e.g., spontaneous social exclusions and distancing, crowd avoidance and voluntary vaccination adaptation). In particular, we use SIR(B)S (e.g., susceptible-infected-recovered with additional behavioural component) model to investigate the impact of homo-psychologicus aspects of epidemics. We focus on reactionary behavioural changes, which apply to both social distancing and voluntary vaccination participations. Our analyses reveal complex relationships between spontaneous and uncoordinated behavioural changes, the emergence of its contagion properties, and mitigation of infectious diseases. We find that the presence of effective behavioural changes can impede the persistence of disease. Furthermore, it was found that under perfect effective behavioural change, there are three regions in the response factor (e.g., imitation and/or reactionary) and behavioural scale factor (e.g., global/local) factors ρ-α behavioural space. Mainly, (1) disease is always endemic even in the presence of behavioural change, (2) behavioural-prevalence plasticity is observed and disease can sometimes be eradication, and (3) elimination of endemic disease under permanence of permanent behavioural change is achieved. These results suggest that preventive behavioural changes (e.g., non-pharmaceutical prophylactic measures, social distancing and exclusion, crowd avoidance) are influenced by individual differences in perception of risks and are a salient feature of epidemics. Additionally, these findings indicates that care needs to be taken when considering the effect of adaptive behavioural change in predicting the course of epidemics, and as well as the interpretation and development of the public health measures that account for spontaneous behavioural changes. "
AUTHORS
Kamal Barley
Alhaji Cherif
Marcel Hurtado
PUBLISHED
2016 in Epidemics

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Individual preventive social distancing during an epidemic may have negative population-level outcomes
FUNDERS
Simons Foundation , Vetenskapsrådet , Engineering and Physical Sciences Research Council , Knut och Alice Wallenbergs Stiftelse
You can view the abstract at: https://doi.org/10.1098/rsif.2018.0296
AUTHORS
Tom Britton
David Sirl
Frank Ball
Ka Yin Leung
PUBLISHED
2018 in Journal of the Royal Society Interface

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Game theory of social distancing in response to an epidemic.
"Social distancing practices are changes in behavior that prevent disease transmission by reducing contact rates between susceptible individuals and infected individuals who may transmit the disease. Social distancing practices can reduce the severity of an epidemic, but the benefits of social distancing depend on the extent to which it is used by individuals. Individuals are sometimes reluctant to pay the costs inherent in social distancing, and this can limit its effectiveness as a control measure. This paper formulates a differential-game to identify how individuals would best use social distancing and related self-protective behaviors during an epidemic. The epidemic is described by a simple, well-mixed ordinary differential equation model. We use the differential game to study potential value of social distancing as a mitigation measure by calculating the equilibrium behaviors under a variety of cost-functions. Numerical methods are used to calculate the total costs of an epidemic under equilibrium behaviors as a function of the time to mass vaccination, following epidemic identification. The key parameters in the analysis are the basic reproduction number and the baseline efficiency of social distancing. The results show that social distancing is most beneficial to individuals for basic reproduction numbers around 2. In the absence of vaccination or other intervention measures, optimal social distancing never recovers more than 30% of the cost of infection. We also show how the window of opportunity for vaccine development lengthens as the efficiency of social distancing and detection improve."
AUTHOR
Timothy C Reluga
PUBLISHED
2010 in PLoS Computational Biology

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Which Measures are Effective in Containing COVID-19? Empirical Research Based on Prevention and Control Cases in China
"Various epidemic prevention and control measures aimed at reducing person-to-person contact has paid a certain cost while controlling the epidemic. So accurate evaluation of these measures helps to maximize the effectiveness of prevention and control while minimizing social costs. In this paper, we develop the model in Dirk Brockmann and Dirk Helbing (2013) to theoretically explain the impact mechanism of traffic control and social distancing measures on the spread of the epidemic, and empirically tests the effect of the two measures in China at the present stage using econometric approach. We found that both traffic control and social distancing measures have played a very good role in controlling the development of the epidemic. Nationally, social distancing measures are better than traffic control measures; the two measures are complementary and their combined action will play a better epidemic prevention effect; Traffic control and social distancing do not work everywhere. Traffic control only works in cities with higher GDP per capita and population size, while fails in cities with lower GDP per capita and population size. In cities with lower population size, social distancing becomes inoperative; the rapid and accurate transmission of information, a higher protection awareness of the public, and a stronger confidence of residents in epidemic prevention can promote the realization of the measure effects. The findings above verify the effectiveness and correctness of the measures implemented in China at present, at the same time, we propose that it is necessary to fully consider the respective characteristics of the two measures, cooperating and complementing each other; what's more, measures should be formulated according to the city's own situation, achieving precise epidemic prevention; Finally, we should increase the transparency of information, improve protection awareness of the public, guide emotions of the public in a proper way, enhancing public confidence."
AUTHORS
Dandan Zhan
Ziwen He
Junpei Huang
Shanlang Lin
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Controlling epidemic spread by social distancing: do it well or not at all.
"Background: Existing epidemiological models have largely tended to neglect the impact of individual behaviour on the dynamics of diseases. However, awareness of the presence of illness can cause people to change their behaviour by, for example, staying at home and avoiding social contacts. Such changes can be used to control epidemics but they exact an economic cost. Our aim is to study the costs and benefits of using individual-based social distancing undertaken by healthy individuals as a form of control.

Methods: Our model is a standard SIR model superimposed on a spatial network, without and with addition of small-world interactions. Disease spread is controlled by allowing susceptible individuals to temporarily reduce their social contacts in response to the presence of infection within their local neighbourhood. We ascribe an economic cost to the loss of social contacts, and weigh this against the economic benefit gained by reducing the impact of the epidemic. We study the sensitivity of the results to two key parameters, the individuals' attitude to risk and the size of the awareness neighbourhood.

Results: Depending on the characteristics of the epidemic and on the relative economic importance of making contacts versus avoiding infection, the optimal control is one of two extremes: either to adopt a highly cautious control, thereby suppressing the epidemic quickly by drastically reducing contacts as soon as disease is detected; or else to forego control and allow the epidemic to run its course. The worst outcome arises when control is attempted, but not cautiously enough to cause the epidemic to be suppressed. The next main result comes from comparing the size of the neighbourhood of which individuals are aware to that of the neighbourhood within which transmission can occur. The control works best when these sizes match and is particularly ineffective when the awareness neighbourhood is smaller than the infection neighbourhood. The results are robust with respect to inclusion of long-range, small-world links which destroy the spatial structure, regardless of whether individuals can or cannot control them. However, addition of many non-local links eventually makes control ineffective.

Conclusions: These results have implications for the design of control strategies using social distancing: a control that is too weak or based upon inaccurate knowledge, may give a worse outcome than doing nothing.

"
AUTHORS
Adam Kleczkowski
Savi Maharaj
PUBLISHED
2012 in BMC public health

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A simulation analysis to characterize the dynamics of vaccinating behaviour on contact networks.
"Background: Human behavior influences infectious disease transmission, and numerous "prevalence-behavior" models have analyzed this interplay. These previous analyses assumed homogeneously mixing populations without spatial or social structure. However, spatial and social heterogeneity are known to significantly impact transmission dynamics and are particularly relevant for certain diseases. Previous work has demonstrated that social contact structure can change the individual incentive to vaccinate, thus enabling eradication of a disease under a voluntary vaccination policy when the corresponding homogeneous mixing model predicts that eradication is impossible due to free rider effects. Here, we extend this work and characterize the range of possible behavior-prevalence dynamics on a network.

Methods: We simulate transmission of a vaccine-preventable infection through a random, static contact network. Individuals choose whether or not to vaccinate on any given day according to perceived risks of vaccination and infection.

Results: We find three possible outcomes for behavior-prevalence dynamics on this type of network: small final number vaccinated and final epidemic size (due to rapid control through voluntary ring vaccination); large final number vaccinated and significant final epidemic size (due to imperfect voluntary ring vaccination), and little or no vaccination and large final epidemic size (corresponding to little or no voluntary ring vaccination). We also show that the social contact structure enables eradication under a broad range of assumptions, except when vaccine risk is sufficiently high, the disease risk is sufficiently low, or individuals vaccinate too late for the vaccine to be effective.

Conclusion: For populations where infection can spread only through social contact network, relatively small differences in parameter values relating to perceived risk or vaccination behavior at the individual level can translate into large differences in population-level outcomes such as final size and final number vaccinated. The qualitative outcome of rational, self interested behaviour under a voluntary vaccination policy can vary substantially depending on interactions between social contact structure, perceived vaccine and disease risks, and the way that individual vaccination decision-making is modelled.

"
AUTHORS
Chris T Bauch
Ana Perisic
PUBLISHED
2009 in BMC Infectious Diseases

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[Model to estimate epidemic patterns of influenza A (H1N1) in Mexico].
"Objective: Apply a mathematical model to estimate the epidemic patterns of influenza A (H1N1) in Mexico during the stages of application and suspension of measures to mitigate the epidemic.

Methods: The effective reproductive number (R) for each state of Mexico during and after the application of social distancing measures was estimated by the SIR model (susceptible, infected, and recovered individuals) based on data published by the Ministry of Health of Mexico.

Results: From the beginning of the outbreak until suspension of school activities (28 April-13 May 2009), the national median of R was 1.13. In the following period (14 May-17 July 2009) the national median of R decreased to 1.01.

Conclusions: It was demonstrated that several epidemic scenarios occurred at the national level. It is suggested that heterogeneous patterns at the state level be taken into account in decision-making on the adoption of measures to mitigate influenza epidemics.

"
AUTHORS
Juan Carlos Mendoza-Pérez
Bárbara Aida Flores-Aldana
Jimena Fritz-Hernández
Rubén López-Molina
Louis Martínez-Matsushita
Estela Navarro-Robles
PUBLISHED

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Sickness behaviour reduces network centrality in wild vampire bats
"AbstractSickness behaviours, like lethargy, can slow the spread of pathogens across a social network. We conducted a field experiment to investigate how sickness behaviour reduces individual connectedness in a high-resolution dynamic social network. We captured adult female vampire bats (Desmodus rotundus) from a wild roost. To create ‘sick’ bats, we injected a random half of the bats (n=16) with the immune-challenging substance, lipopolysaccharide, and injected control bats with saline (n=15). Over the next three days, we used proximity sensors to continuously track their associations under natural conditions. The ‘sick’ bats showed a clear decrease in social connectedness (degree, strength, and eigenvector centrality). Bats in the control group encountered fewer ‘sick’ bats and also spent less time near them. These effects varied by time of day and declined over 48 hours. High-resolution proximity data allow researchers to define network connections based on how a pathogen spreads (e.g. the minimum contact time or distance for transmission). We therefore show how the estimate of the sickness effect changes as network ties are defined using varying distances and durations of association. Tracking the effects of sickness behaviour on high-resolution dynamic social networks can help create more sophisticated simulations of pathogen transmission through structured populations."
AUTHORS
Simon P. Ripperger
Gerald G. Carter
Sebastian Stockmaier
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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A framework for identifying regional outbreak and spread of COVID-19 from one-minute population-wide surveys
"Coronavirus infection spreads in clusters and therefore early identification of these clusters is critical for slowing down the spread of the virus. Here, we propose that daily population-wide surveys that assess the development of symptoms caused by the virus could serve as a strategic and valuable tool for identifying such clusters to inform epidemiologists, public health officials, and policy makers. We show preliminary results from a survey of over 38,000 Israelis and call for an international consortium to extend this concept in order to develop predictive models. We expect such data to allow: Faster detection of spreading zones and patients; Obtaining a current snapshot of the number of people in each area who have developed symptoms; Predicting future spreading zones several days before an outbreak occurs; Evaluating the effectiveness of the various social distancing measures taken, and their contribution to reduce the number of symptomatic people. Such information can provide a valuable tool for decision makers to decide which areas need strengthening of social distancing measures and which areas can be relieved. Researchers from the U.S, Spain, and Italy have adopted our approach and we are collaborating to further improve it. We call with urgency for other countries to join this international consortium, and to share methods and data collected from these daily, simple, one-minute surveys."
AUTHORS
Hagai Rossman
Eran Segal
Ayya Keshet
Ori Cohen
Amir Gavrieli
Yuval Dor et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Delaying the COVID-19 epidemic in Australia: Evaluating the effectiveness of international travel bans
"Following the outbreak of novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) or COVID-19 in Wuhan, China late 2019, different countries have put in place interventions such as travel ban, proper hygiene, and social distancing to slow the spread of this novel virus. We evaluated the effects of travel bans in the Australia context and projected the epidemic until May 2020. Our modelling results closely align with observed cases in Australia indicating the need for maintaining or improving on the control measures to slow down the virus."
AUTHORS
Michael Meehan
Diana Rojaz Alvarez
Adeshina Israel Adekunle
James Trauer
Emma McBryde
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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COVID-19 infection: Origin, transmission, and characteristics of human coronaviruses
"The coronavirus disease 19 (COVID-19) is a highly transmittable and pathogenic viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged in Wuhan, China and spread around the world. Genomic analysis revealed that SARS-CoV-2 is phylogenetically related to severe acute respiratory syndrome-like (SARS-like) bat viruses, therefore bats could be the possible primary reservoir. The intermediate source of origin and transfer to humans is not known, however, the rapid human to human transfer has been confirmed widely. There is no clinically approved antiviral drug or vaccine available to be used against COVID-19. However, few broad-spectrum antiviral drugs have been evaluated against COVID-19 in clinical trials, resulted in clinical recovery. In the current review, we summarize and comparatively analyze the emergence and pathogenicity of COVID-19 infection and previous human coronaviruses severe acute respiratory syndrome coronavirus (SARS-CoV) and middle east respiratory syndrome coronavirus (MERS-CoV). We also discuss the approaches for developing effective vaccines and therapeutic combinations to cope with this viral outbreak."
AUTHORS
Nadia Bashir
Muhammad Adnan Shereen
Abeer Kazmi
Rabeea Siddique
Suliman Khan
PUBLISHED
2020 in Journal of Advanced Research

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Sitagliptin: a potential drug for the treatment of SARS-CoV-2?
"Recently, an outbreak of fatal coronavirus, SARS-CoV-2, has emerged from China and is rapidly spreading worldwide. As the coronavirus pandemic rages, drug discovery and development become even more challenging. Drug repurposing of the antimalarial drug chloroquine and its hydroxylated form had demonstrated apparent effectiveness in the treatment of COVID-19 associated pneumonia in clinical trials. SARS-CoV-2 spike protein shares 31.9% sequence identity with the spike protein presents in the Middle East Respiratory Syndrome Corona Virus (MERS-CoV), which infects cells through the interaction of its spike protein with the DPP4 receptor found on macrophages. Sitagliptin, a DPP4 inhibitor, that is known for its antidiabetic, immunoregulatory, anti-inflammatory, and beneficial cardiometabolic effects has been shown to reverse macrophage responses in MERS-CoV infection and reduce CXCL10 chemokine production in AIDS patients. We suggest that Sitagliptin may be beneficial alternative for the treatment of COVID-19 disease especially in diabetic patients and patients with preexisting cardiovascular conditions who are already at higher risk of COVID-19 infection."
AUTHOR
Sanaa Bardaweel
PUBLISHED
2020 in Center for Open Science

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Coronavirus disease 2019 (COVID-19): current status and future perspectives
"Coronavirus disease 2019 (COVID-19) originated in the city of Wuhan, Hubei Province, Central China, and has spread quickly to 72 countries to date. COVID-19 is caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [previously provisionally known as 2019 novel coronavirus (2019-nCoV)]. At present, the newly identified SARS-CoV-2 has caused a large number of deaths with tens of thousands of confirmed cases worldwide, posing a serious threat to public health. However, there are no clinically approved vaccines or specific therapeutic drugs available for COVID-19. Intensive research on the newly emerged SARS-CoV-2 is urgently needed to elucidate the pathogenic mechanisms and epidemiological characteristics and to identify potential drug targets, which will contribute to the development of effective prevention and treatment strategies. Hence, this review will focus on recent progress regarding the structure of SARS-CoV-2 and the characteristics of COVID-19, such as the aetiology, pathogenesis and epidemiological characteristics."
AUTHORS
Shang-Ming Liu
Heng Li
Chao-Ke Tang
Shi-Lin Tang
Xiao-Hua Yu
PUBLISHED
2020 in International Journal of Antimicrobial Agents

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Literature review
COVID-19 Drug Discovery Using Intensive Approaches
FUNDERS
Japan Agency for Medical Research and Development , Japan Society for the Promotion of Science London , Princess Takamatsu Cancer Research Fund
"Since the infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China during December 2019, the coronavirus disease 2019 (COVID-19) has spread on a global scale, causing the World Health Organization (WHO) to issue a warning. While novel vaccines and drugs that target SARS-CoV-2 are under development, this review provides information on therapeutics which are under clinical trials or are proposed to antagonize SARS-CoV-2. Based on the information gained from the responses to other RNA coronaviruses, including the strains that cause severe acute respiratory syndrome (SARS)-coronaviruses and Middle East respiratory syndrome (MERS), drug repurposing might be a viable strategy. Since several antiviral therapies can inhibit viral replication cycles or relieve symptoms, mechanisms unique to RNA viruses will be important for the clinical development of antivirals against SARS-CoV-2. Given that several currently marketed drugs may be efficient therapeutic agents for severe COVID-19 cases, they may be beneficial for future viral pandemics and other infections caused by RNA viruses when standard treatments are unavailable."
AUTHORS
Takaaki Hirotsu
Toru Kitagawa
Andrea Vecchione
Ayumu Asai
Masamitsu Konno
Hidetoshi Eguchi et al
PUBLISHED
2020 in International Journal of Molecular Sciences

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Protein structure analysis of the interactions between SARS-CoV-2 spike protein and the human ACE2 receptor: from conformational changes to novel neutralizing antibodies.
"The recent severe acute respiratory syndrome, known as Corona Virus Disease 2019 (COVID-19) has spread so much rapidly and severely to induce World Health Organization (WHO) to declare state of emergency over the new coronavirus SARS-CoV-2 pandemic. While several countries have chosen the almost complete lock-down for slowing down SARS-CoV-2 spread, scientific community is called to respond to the devastating outbreak by identifying new tools for diagnosis and treatment of the dangerous COVID-19. With this aim we performed an in silico comparative modeling analysis, which allows to gain new insights about the main conformational changes occurring in the SARS-CoV-2 spike protein, at the level of the receptor binding domain (RBD), along interactions with human cells angiotensin converting enzyme 2 (ACE2) receptor, that favour human cell invasion. Furthermore, our analysis provides i) an ideal pipeline to identify already characterized antibodies that might target SARS-CoV-2 spike RBD, for preventing interactions with the human ACE2, and ii) instructions for building new possible neutralizing antibodies, according to chemical/physical space restraints and complementary determining regions (CDR) mutagenesis of the identified existing antibodies. The proposed antibodies show in silico a high affinity for SARS-CoV-2 spike RBD and can be used as reference antibodies also for building new high affinity antibodies against present and future coronavirus able to invade human cells through interactions of their spike proteins with the human ACE2. More in general, our analysis provides indications for the set-up of the right biological molecular context for investigating spike RBD-ACE2 interactions for the development of new vaccines, diagnosis kits and other treatments based on the usage or the targeting of SARS-CoV-2 spike protein."
AUTHORS
Francesco Busto
Ciro Leonardo Pierri
Ivan Mercurio
Vincenzo Tragni
Anna De Grassi
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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No Place like Home: A Cross-National Assessment of the Efficacy of Social Distancing during the COVID-19 Pandemic (Preprint)
"
BACKGROUND
In the absence of a cure in the time of pandemics, social distancing measures seem to be the most effective intervention to slow down the spread of disease. Various simulation-based studies have been conducted in the past to investigate the effectiveness of such measures. While those studies unanimously confirm the mitigating effect of social distancing on the disease spread, the reported effectiveness varies from 10% to more than 90% reduction in the number of infections. This level of uncertainty is mostly due to the complex dynamics of epidemics and their time-variant parameters. A real transactional data, however, can reduce the uncertainty and provide a less noisy picture of social distancing effectiveness.


OBJECTIVE
In this paper, we integrate multiple transactional data sets (GPS mobility data from Google and Apple as well as disease statistics data from ECDC) to study the role of social distancing policies in 26 countries wherein the transmission rate of the COVID-19 pandemic is analyzed over a course of five weeks.


METHODS
Relying on the SIR model and official COVID-19 reports we first calculated weekly transmission rate (β) of the coronavirus disease in 26 countries for five consecutive weeks. Then we integrated that with the Google’s and Apple’s mobility data sets for the same time frame and used a machine learning approach to investigate the relationship between mobility factors and β values.


RESULTS
Gradient Boosted Trees (GBT) regression analysis showed that changes in mobility patterns, resulted from social distancing policies, explain around 47% of variation in the disease transmission rate.


CONCLUSIONS
Consistent with simulation-based studies, real cross-national transactional data confirms the effectiveness of social distancing interventions in slowing down spread of the disease. Apart from providing a less noisy and more generalizable support for the whole social distancing idea, we provide specific insights for public health policy makers as to what locations should be given a higher priority for enforcing social distancing measures.


CLINICALTRIAL
N/A
"
AUTHORS
Behrooz Davazdahemami
Enes Eryarsoy
Dursun Delen
PUBLISHED
2020 in JMIR Publications Inc.

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The Spread of Social Distancing
You can view the abstract at: https://doi.org/10.2139/ssrn.3610504
AUTHORS
Sami Smalling
Noah Newberger
Jonathan A Cook
PUBLISHED
2020 in SSRN Electronic Journal

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Early transmission dynamics and control of COVID-19 in a southern hemisphere setting: Lima-Peru, February 29th-March 30th, 2020 .
"The COVID-19 pandemic that emerged in Wuhan China rapidly spread around the world. The daily incidence trend has been rapidly rising in Latin America since March 2020 with the great majority of the cases reported in Brazil (28320) followed by Peru (11475) as of April 15th, 2020. Although Peru implemented social distancing measures soon after the confirmation of its first case on March 6th, 2020, the daily number of new COVID-19 cases continues to increase. We assessed the early COVID-19 transmission dynamics and the effect of social distancing interventions in Lima, Peru. We estimate the transmission potential of COVID-19, R, during the early phase of the outbreak, from the daily series of imported and autochthonous cases by the date of symptoms onset as of March 30th, 2020. We also assessed the effect of social distancing interventions in Lima by generating short-term forecasts grounded on the early transmission dynamics before interventions were put in place. Prior to the implementation of the social distancing measures in Lima, we estimated the reproduction number at 2.3 (95% CI: 2.0, 2.5). Our analysis indicates that school closures and other social distancing interventions have helped stem the spread of the virus, with the nearly exponential growth trend shifting to an approximately linear growth trend after the national emergency declaration. The COVID-19 epidemic in Lima followed an early exponential growth trend, which slowed down and turned into an almost linear growth trend after broad scale social distancing interventions were put in place by the government."
AUTHORS
Leonardo Rojas-Mezarina
Andree Valle
Mary F. Reyes
Gabriela G Soto-Cabezas
Amna Tariq
Cesar V. Munayco et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Decline in global COVID-19 transmission
"We analyzed COVID-19 data through April 15, 2020 using a partially observed Markov process.
Our method uses a hybrid deterministic and stochastic formalism that allows for time variable transmission rates and detection probabilities. The model was fit using iterated particle filtering to case count and death count time series from 51 countries. We found evidence for a declining transmission rate in 42 of the 51 examined countries. Of those 42 countries 34 have significant evidence for subcritical transmission rates, although the decline in new cases are relatively slow compared to the initial growth rates. This suggests that global scale social distancing efforts to slow the spread of COVID-19 are effective although they need to be strengthened in many regions and maintained in others to avoid further resurgence of COVID-19. The slow decline also suggests alternative strategies to control the virus are needed before social distancing efforts are partially relaxed."
AUTHORS
Grant Meadors
Nick Hengartner
Ethan Obie Romero-Severson
Ruian Ke
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Corona kills corona: convalescent sera option for global war against corona virus disease 2019
"On December 31st, 2019 China reported first case of atypical pneumonia in Wuhan, the capital of Hubei province. The causative virus was found to be a beta coronavirus, closely related to the severe acute respiratory syndrome coronavirus (SARS-CoV-1) from 2003 and similar to Sarbeco viruses isolated from bats. It was therefore termed SARS-CoV-2 and the disease was named corona virus disease 2019 (COVID-19). The outbreak in Wuhan expanded quickly and led to the lockdown of Wuhan and other parts of China. While the lockdown, at least temporarily, brought the situation under control in China, but SARS-CoV-2 spread globally causing a pandemic with more than 4 lakh infections and about 19000 fatalities (as of March 25, 2020). Nucleic acid tests that detect the SARS-CoV-2 RNA genome were quickly developed and are now widely employed to diagnose COVID-19."
AUTHORS
Babita .
Mahavir Jangra
S. K. Jha
Anita Punia
PUBLISHED
2020 in International Journal Of Community Medicine And Public Health

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Coronavirus Disease 2019 (COVID-19): Prevention and Disinfection
"The successful prevention of spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection depends on the routine application of preventive measures taken to prevent this spread. Strategies for preventing transmission of the disease include practices such as social/physical distancing, self-quarantine and isolation when appropriate, maintaining overall good personal hygiene practices like of handwashing and protecting others from coughs and sneezes by wearing Personal Protective Equipment (PPE). Moreover, Transmission of coronavirus occurs through contaminated surfaces where it may remain viable for hours to days. It is recommended to clean visibly dirty surfaces followed by disinfection through applying surface-appropriate disinfectants. In this review, we summarized the recommendations on the prevention, cleaning, and disinfection of the novel beta-coronavirus, SARS-CoV-2, in order to help lower the chances of contracting Covid-19 and spreading it to someone else.

Keywords: SARS-CoV-2; Coronavirus Disease; COVID-19, Disinfection"
AUTHORS
Nabih Mohammad Lawand Samaa Al Tabbah
Nabih Mohammad Lawand
PUBLISHED
2020 in International Journal of Biology and Medicine

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Early Mandated Social Distancing is a Strong Predictor of Reduction in Highest Number of New COVID-19 cases per Day within Various Geographic Regions
"Mandated social distancing has been globally applied to limit the spread of corona virus disease 2019 (COVID-19) from highly pathogenic severe acute respiratory syndrome (SARS) -associated coronavirus 2 (SARS-CoV-2). The benefit of this community-based intervention in limiting COVID-19 has not been proven nor quantified. We examined the effect of timing of mandated social distancing on the rate of COVID-19 in 119 geographic regions derived from 41 states within United States and 78 countries. We found that highest number of new COVID-19 cases per day per million persons was significantly associated with total number of COVID-19 cases per million persons on the day before mandated social distancing (Beta;=0.66, p&lt;0.0001). Our findings suggest that the initiation of mandated social distancing for each doubling in number of existing COVID-19 cases would result in eventual peak with 58% higher number of COVID-19 infections per day. Subgroup analysis on those regions where the highest number of new COVID-19 cases per day have peaked increased Beta to .85 (p&lt;0.0001). We demonstrate that initiating mandated social distancing at a 10 times smaller number of COVID-19 cases will reduce the number of daily new COVID-19 cases at peak by 80% highlighting the importance of this community-based intervention."
AUTHORS
Adnan I Qureshi
Ayesha Khan Suri
Habibullah Khan Suri
Haitao Shu
M. Fareed K. Suri
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Exploring Dependence of COVID-19 on Environmental Factors and Spread Prediction in India
"Abstract
The pandemic of “Corona Virus Disease 2019” or COVID-19 has taken the world by storm. Majority of nations of the world have been challenged by the novel coronavirus, which is supposedly of zoonotic origin and is known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The present work attempts to evaluate the spread of COVID-19 in India. The methodology of assessment uses SEIR (Susceptible-Exposed-Infectious-Removed) model to establish the impact of socio-behavioural aspect, especially social distancing, affecting the numbers of COVID-19 cases per day. The lockdown initiated by Government of India (GoI) scenario is weighed against a scenario with a possible initiation of community spread due to crowded gatherings in India. The resultant changes, as against the lockdown scenario, has been reported in terms of the increase in the number of cases and stretch of the timeline to mitigate the COVID-19 spread. Impact of environmental factors like temperature and relative humidity have also been analyzed using statistical methods, including Response Surface Methodology (RSM) and Correlation. It has been found that the spread of cases is dependent on environmental conditions, i.e. temperature and relative humidity. This study is expected to help the policymakers and stakeholders to device an improved action plan to alleviate the COVID-19 spread, especially in India."
AUTHORS
Rakesh Kumar
Avneesh Anshul
Saima Anjum
Ankit Gupta
Hemant Bherwani
PUBLISHED
2020 in Research Square

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Favipiravir strikes the SARS-CoV-2 at its Achilles heel, the RNA polymerase
"The ongoing Corona Virus Disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has emphasized the urgent need for antiviral therapeutics. The viral RNA-dependent-RNA-polymerase (RdRp) is a promising target with polymerase inhibitors successfully used for the treatment of several viral diseases. Here we show that Favipiravir exerts an antiviral effect as a nucleotide analogue through a combination of chain termination, slowed RNA synthesis and lethal mutagenesis. The SARS-CoV RdRp complex is at least 10-fold more active than any other viral RdRp known. It possesses both unusually high nucleotide incorporation rates and high-error rates allowing facile insertion of Favipiravir into viral RNA, provoking C-to-U and G-to-A transitions in the already low cytosine content SARS-CoV-2 genome. The coronavirus RdRp complex represents an Achilles heel for SARS-CoV, supporting nucleoside analogues as promising candidates for the treatment of COVID-19."
AUTHORS
Veronique Fattorini
Genevieve Piorkowski
Franck Touret
Johanna Huchting
Thi-Tuyet-Nhung Le
Barbara Selisko et al
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Conditions for a second wave of COVID-19 due to interactions between disease dynamics and social processes
"In May 2020, many jurisdictions around the world began lifting physical distancing restrictions against the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), giving rise to concerns about a possible second wave of coronavirus disease 2019 (COVID-19). These restrictions were imposed as a collective population response to the presence of COVID-19 in communities. However, lifting restrictions is also a population response to their socio-economic impacts, and is expected to increase COVID-19 cases, in turn. This suggests that the COVID-19 pandemic exemplifies a coupled behaviour-disease system. Here we develop a minimal mathematical model of the interaction between social support for school and workplace closure and the transmission dynamics of SARS-CoV-2. We find that a second wave of COVID-19 occurs across a broad range of plausible model input parameters, on account of instabilities generated by behaviour-disease interactions. We conclude that second waves of COVID-19--should they materialize--can be interpreted as the outcomes of nonlinear interactions between disease dynamics and population behaviour."
AUTHORS
Chris T Bauch
Madhur Anand
Jean M Tcheunche
Peter Jentsch
Frank T Ndjomatchoua
Sansao A Pedro
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Modeling the dynamics of COVID19 spread during and after social distancing
"Non-pharmaceutical intervention measures, such as social distancing, have so far been the only means to slow the spread of COVID19. In the United States, strict social distancing has resulted in different types infection dynamics. In some states, such as New York, extensive infection spread was followed by a pronounced decline of infection levels. In other states, such as California, less infection spread occurred before strict social distancing, and a different pattern was observed. Instead of a pronounced infection decline, a long-lasting plateau is evident, characterized by similar daily new infection levels. While these plateau dynamics cannot be readily reproduced with standard SIR infection models, we show that network models, in which individuals and their social contacts are explicitly tracked, can reproduce the plateau if network connections are cut due to social distancing measures. The reason is that in networks characterized by a degree of 2D spatial structure, infection tends to spread quadratically with time, but as edges are randomly removed, the infection spreads along nearly one-dimensional infection "corridors", resulting in plateau dynamics. Interestingly, the plateau dynamics are predicted to eventually transition into an infection decline phase without any further increase in social distancing measures. Additionally, the models suggest that a potential second wave becomes significantly less pronounced if social distancing is only relaxed once the dynamics have transitioned to the decline phase. The network models analyzed here allow us to interpret and reconcile different infection dynamics during social distancing observed in various US states."
AUTHORS
Dominik Wodarz
Natalia L. Komarova
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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SHELTER IN PLACE ORDER CONTAINED COVID-19 GROWTH RATE IN GREECE
"Background: The Greek authorities implemented the strong social distancing measures within the first few weeks after the first confirmed case of the virus to curtail the COVID-19 growth rate.
Objectives: To estimate the effect of the two-stage strong social distancing measures, the closure of all non-essential shopping centers and businesses on March 16 and the shelter in place orders (SIPOs) on March 23 on the COVID-19 growth rate in Greece
Methods: We obtained data on COVID-19 cases in Greece from February 26th through May 4th from publicly available sources. An interrupted time-series regression analysis was used to estimate the effect of the measures on the exponential growth of confirmed COVID-19 cases, controlling for the number of daily testing, and weekly fixed-effects.
Results: The growth rate of the COVID-19 cases in the pre-policies implementation period was positive as expected (p=0.003). Based on the estimates of the interrupted time-series, our results indicate that the SIPO on March 23 significantly slowed the growth rate of COVID-19 in Greece (p=0.04). However, we did not find evidence on the effectiveness of standalone and partial measures such as the non-essential business closures implemented on March 16 on the COVID-19 spread reduction.
Discussion: The combined social distancing measures implemented by the Greek authorities within the first few weeks after the first confirmed case of the virus reduced the COVID-19 growth rate. These findings provide evidence and highlight the effectiveness of these measures to flatten the curve and to slow the spread of the virus. "
AUTHORS
Kyriakos Souliotis
Evangelia Steletou
Ilias Christodoulou
Aris Giannouchos
Theodoros Giannouchos
PUBLISHED
2020 in Cold Spring Harbor Laboratory

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Social Distancing, Lockdown Obligatory, and Response Satisfaction During COVID-19 Pandemic: Perception of Nigerian Social Media Users
"Background: Pandemics are challenging for clinical and public health agencies and policymakers because of the scientific and medical uncertainty that accompanies novel viruses like COVID-19 makes an increase of morbidity and mortality prominent. Consequently, there is a need to evaluate the public perception of social distancing, lockdown obligatory, and response satisfactory during the pandemic.&#x0D;
Methods: This cross-sectional survey used an anonymous online google based questionnaire to collect data from respondents via social media platforms. The online survey was conducted among social media users from 1st to 30th April 2020. A snowball sampling technique was employed to recruit respondents for the survey. A total of 1,131 respondents responded across the country.&#x0D;
Results: Nine out of every ten respondents believed that social distancing is an effective measure to reduce the spread of COVID-19. Also, 8 out of every ten respondents agreed with the lockdown measures. However, just 36.8% think their government is doing enough to stop the outbreak, and only 25% of the respondents were satisfied with the country’s response to the worldwide epidemic. The age of respondents was found to be significantly associated with satisfaction with emergency response during pandemics.&#x0D;
Conclusion: It could be concluded that Nigerian public accepted social distancing as an effective way of curbing the spread of COVID-19 and general acceptance on lockdown obligatory; however, more than half of respondents expressed non-satisfactory with government and other agencies responses during the pandemics."
AUTHORS
Obasanjo Afolabi Bolarinwa
Olalekan Seun Olagunju
Tesleem Kayode Babalola
PUBLISHED
2020 in Advanced Journal of Social Science

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Nationwide results of COVID-19 contact tracing in South Korea: Individual participant data from an epidemiological survey (Preprint)
"
BACKGROUND
Evidence regarding the effectiveness of contact tracing of coronavirus disease 2019 (COVID-19) and the related social distancing is limited and inconclusive.


OBJECTIVE
To investigate the epidemiological characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in South Korea and evaluate whether a social distancing campaign is effective in mitigating the spread of COVID-19.


METHODS
We used contract tracing data to investigate the epidemic characteristics of transmission of SARS-CoV-2 in South Korea and evaluate whether a social distancing campaign is effective to mitigate the spread of COVID-19. We calculated the mortality rate for COVID-19 by infection type (cluster versus non-cluster) and tested whether new confirmed COVID-19 trends changed after a social distancing campaign.


RESULTS
There were 2537 patients with confirmed COVID-19 who completed the epidemiologic survey: 1305 (51.4%) cluster cases and 1232 (48.6%) non-cluster cases. The mortality rate was significantly higher in cluster cases linked to medical facilities (0.41% versus 7.70%; adjusted percentage difference, 7.99%; 95% confidence interval [CI], 5.83 to 10.14) and long-term care facilities (0.41% versus 8.60%; adjusted percentage difference, 7.56%; 95% CI, 5.66 to 9.47) than in non-cluster cases. The change in trends of newly confirmed COVID-19 cases before and after the social distancing campaign was significantly negative in the entire cohort (adjusted trend difference, -2.28; 95% CI, -3.88 to -0.68) and the cluster infection group (adjusted trend difference, -0.96; 95% CI, -1.83 to -0.09).


CONCLUSIONS
In a nationwide contact tracing study in South Korea, COVID-19 linked to medical and long-term care facilities significantly increased the risk of mortality compared to non-cluster COVID-19. A social distancing campaign decreased the spread of COVID-19 in South Korea and differentially affected cluster infections of SARS-CoV-2.


CLINICALTRIAL
N/ACOVID-19; contact tracing; coronavirus.
"
AUTHORS
Hyun Yong Koh
In Kyung Yoo
Yoon-Sik Cho
Jee Myung Yang
Woontak Yuh
Seung Won Lee et al
PUBLISHED
2020 in JMIR Publications Inc.

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Literature review
Blood Safety in SARS-CoV-2 Infection
": SARS-CoV-2 is a novel infectious agent that rapidly spread from a single city in China to all parts of the world. Right now, the world is facing a major pandemic crisis and every infected patient can infect the other two to three persons. The non-specific symptoms at the early stages of coronavirus 2019 (Covid-19) and also the presence of infected asymptomatic patients result in the absence of accurate estimation of infected patients. Although coronaviruses often affect the upper or lower respiratory tract, viral shedding in plasma or serum can occur and therefore, there is a theoretical risk regarding the transmission of these viruses by transfusion. Experience with other viruses from the corona family group (SARS-CoV and MERS-CoV) tells us that Covid-19 might have a significant impact on blood supply. Until now, SARS-CoV-2 has not been identified as a transfusion transmissible virus and viremia has only been diagnosed in serious patients who would not be allowed for blood donation. In this review article, the safety of blood products during the Covid-19 outbreak is discussed."
AUTHOR
Mozhgan Hashemieh
PUBLISHED
2020 in Archives of Pediatric Infectious Diseases

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Novel dangerous emergent coronavirus infection
"The genetic diversity of coronaviruses and their variability are provided by high frequency of recombination of their genomic RNA that assists spontaneous emergence of viruses with new characteristics, which potentially may be agents of novel extremely dangerous and exotic infectious diseases. In December 2019 – January 2020 the novel coronavirus disease, caused by SARS-CoV-2 virus, subsequently named COVID-19 (Corona Virus Disease 2019), was revealed in China. The aim of this work is to analyze the possible mechanism of COVID-19 outbreak and the properties of the possible etiological agent of the disease, SARS-CoV-2 virus. A comparison of zoonotic reservoirs of highly pathogenic human coronaviruses, agents of severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and SARS-CoV-2, as well as the clinical signs of the diseases, caused by them, are presented. The possible mechanism of epidemic outbreaks is considered. The chronology of COVID-19 outbreak (later escalated into a pandemic) from the beginning of December to the end of March, taxonomical and molecular-biological characteristics of ethiological agent of disease, SARS-CoV-2 virus, and its place on phylogenetic tree of coronaviruses are presented. The main directions of the struggle with the spread of the infection are considered"
PUBLISHED
2020 in Пандемия COVID-19

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