scholarly journals Differential impact of physical distancing strategies on social contacts relevant for the spread of SARS-CoV-2: evidence from a cross-national online survey, March–April 2020

BMJ Open ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. e050651
Author(s):  
Emanuele Del Fava ◽  
Jorge Cimentada ◽  
Daniela Perrotta ◽  
André Grow ◽  
Francesco Rampazzo ◽  
...  
Keyword(s):  
Online Survey ◽  
Age Groups ◽  
Social Contact ◽  
Face Mask ◽  
Infection Transmission ◽  
Contact Patterns ◽  
The Face ◽  
Gradual Introduction ◽  
The Usa ◽  
Net Reproduction

ObjectivesWe investigate changes in social contact patterns following the gradual introduction of non-pharmaceutical interventions and their implications for infection transmission in the early phase of the pandemic.Design, setting and participantsWe conducted an online survey based on targeted Facebook advertising campaigns across eight countries (Belgium, France, Germany, Italy, the Netherlands, Spain, UK and USA), achieving a sample of 51 233 questionnaires in the period 13 March–12 April 2020. Poststratification weights based on census information were produced to correct for selection bias.Outcome measuresParticipants provided data on social contact numbers, adoption of protective behaviours and perceived level of threat. These data were combined to derive a weekly index of infection transmission, the net reproduction number Rt .ResultsEvidence from the USA and UK showed that the number of daily contacts mainly decreased after governments issued the first physical distancing guidelines. In mid-April, daily social contact numbers had decreased between 61% in Germany and 87% in Italy with respect to pre-COVID-19 levels, mostly due to a contraction in contacts outside the home. Such reductions, which were uniform across age groups, were compatible with an Rt equal or smaller than one in all countries, except Germany. This indicates lower levels of infection transmission, especially in a period of gradual increase in the adoption rate of the face mask outside the home.ConclusionsWe provided a comparable set of statistics on social contact patterns during the COVID-19 pandemic for eight high-income countries, disaggregated by week and other demographic factors, which could be leveraged by the scientific community for developing more realistic epidemic models of COVID-19.

scholarly journals Lockdown impact on age-specific contact patterns and behaviours in France

2020 ◽  
Author(s):  
Paolo Bosetti ◽  
Bich-Tram Huynh ◽  
Armiya Youssouf Abdou ◽  
Marie Sanchez ◽  
Catherine Eisenhauer ◽  
...  
Keyword(s):  
Online Survey ◽  
Age Groups ◽  
Social Contact ◽  
First Trimester ◽  
Professional Activity ◽  
Epidemic Dynamics ◽  
Contact Patterns ◽  
Specific Contact ◽  
Set Up ◽  
The Impact

AbstractIn the first trimester 2020, a significant number of countries implemented general lockdowns of their populations to contain the quickly expanding SARS-CoV-2 epidemic and avoid major saturation of health care capacity. Understanding how these unprecedented measures impacted population behaviour and contact patterns is key to predict more accurately the health, social and economic impacts of such extreme actions if they were to be applied to future outbreaks. We set up an online survey to measure how the lockdown affected social contact patterns in France, and collected information from 42,036 participants aged 18 years and over between April 10 and April 28, 2020. Among the participants who normally worked outside home prior to the lockdown (72% of the survey population), 68% reported that they had moved to working from home and 17% reported being unemployed during the lockdown.Only 2% of participants used public transport during lockdown, as opposed to 37% before it. Participants reported increased frequency of washing hands, switch in greeting behaviour, but generally limited use of masks outside home. 138,934 contacts were reported, with an average 3.3 contacts per individual per day (1.7 for individuals aged >65 years old compared to 3.6 for younger age-groups). This represented a 70% reduction compared with previous surveys, consistent with reductions in transmission rates measured during the lockdown. Contacts in workplaces, shops, and transports on the previous day were respectively reported in only 11%, 31% and 0.5% of the participants. For those who maintained a professional activity outside home, the frequency of contacts at work dropped by 79%. This study shows that the lockdown dramatically affected population’s behavior, work, risk perception and contact patterns. Both frequency and heterogeneity of contacts were affected, impacting potential important features of virus dissemination. Such surveys are essential to evaluate more accurately the impact of past or future lockdowns and anticipate epidemic dynamics in these conditions.

scholarly journals The differential impact of physical distancing strategies on social contacts relevant for the spread of COVID-19: Evidence from a multi-country survey

2020 ◽  
Author(s):  
Emanuele Del Fava ◽  
Jorge Cimentada ◽  
Daniela Perrotta ◽  
André Grow ◽  
Francesco Rampazzo ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Age Groups ◽  
Social Contact ◽  
The United States ◽  
Social Contacts ◽  
Contact Patterns ◽  
The Uk ◽  
Facebook Advertising ◽  
Net Reproduction ◽  
The Impact

AbstractPhysical distancing measures are intended to mitigate the spread of COVID-19, even though their impact on social contacts and disease transmission remains unclear. Obtaining timely data on social contact patterns can help to assess the impact of such protective measures. We conducted an online opt-in survey based on targeted Facebook advertising campaigns across seven European countries (Belgium, France, Germany, Italy, Netherlands, Spain, United Kingdom (UK)) and the United States (US), achieving a sample of 53,708 questionnaires in the period March 13–April 13, 2020. Post-stratification weights were produced to correct for biases. Data on social contact numbers, as well as on protective behaviour and perceived level of threat were collected and used to the expected net reproduction number by week, Rt, with respect to pre-pandemic data. Compared to social contacts reported prior to COVID-19, in mid-April daily social contact numbers had decreased between 49% in Germany and 83% in Italy, ranging from below three contacts per day in France, Spain, and the UK up to four in Germany and the Netherlands. Such reductions were sufficient to bring Rt to one or even below in all countries, except Germany. Evidence from the US and the UK showed that the number of daily social contacts mainly decreased after governments issued the first physical distancing guidelines. Finally, although contact numbers decreased uniformly across age groups, older adults reported the lowest numbers of contacts, indicating higher levels of protection. We provided a comparable set of statistics on social contact patterns during the COVID-19 pandemic for eight high-income countries, disaggregated by week. As these estimates offer a more grounded alternative to the theoretical assumptions often used in epidemiological models, the scientific community could draw on this information for developing more realistic epidemic models of COVID-19.

scholarly journals Lockdown impact on age-specific contact patterns and behaviours, France, April 2020

2021 ◽  
Vol 26 (48) ◽  
Author(s):  
Paolo Bosetti ◽  
Bich-Tram Huynh ◽  
Armiya Youssouf Abdou ◽  
Marie Sanchez ◽  
Catherine Eisenhauer ◽  
...  
Keyword(s):  
Online Survey ◽  
Age Groups ◽  
Professional Activity ◽  
Population Mixing ◽  
Epidemic Dynamics ◽  
Contact Patterns ◽  
Rapid Spread ◽  
Specific Contact ◽  
Transmission Reduction ◽  
The Impact

Background Many countries implemented national lockdowns to contain the rapid spread of SARS-CoV-2 and avoid overburdening healthcare capacity. Aim We aimed to quantify how the French lockdown impacted population mixing, contact patterns and behaviours. Methods We conducted an online survey using convenience sampling and collected information from participants aged 18 years and older between 10 April and 28 April 2020. Result Among the 42,036 survey participants, 72% normally worked outside their home, and of these, 68% changed to telework during lockdown and 17% reported being unemployed during lockdown. A decrease in public transport use was reported from 37% to 2%. Participants reported increased frequency of hand washing and changes in greeting behaviour. Wearing masks in public was generally limited. A total of 138,934 contacts were reported, with an average of 3.3 contacts per individual per day; 1.7 in the participants aged 65 years and older compared with 3.6 for younger age groups. This represented a 70% reduction compared with previous surveys, consistent with SARS-CoV2 transmission reduction measured during the lockdown. For those who maintained a professional activity outside home, the frequency of contacts at work dropped by 79%. Conclusion The lockdown affected the population's behaviour, work, risk perception and contact patterns. The frequency and heterogeneity of contacts, both of which are critical factors in determining how viruses spread, were affected. Such surveys are essential to evaluate the impact of lockdowns more accurately and anticipate epidemic dynamics in these conditions.

scholarly journals Assessing Age-Specific Vaccination Strategies and Post-Vaccination Reopening Policies for COVID-19 Control Using SEIR Modeling Approach

2021 ◽  
Author(s):  
Xia Wang ◽  
Hulin Wu ◽  
Sanyi Tang
Keyword(s):  
Age Structure ◽  
Age Groups ◽  
Social Contact ◽  
The Elderly ◽  
Vaccination Rate ◽  
Social Contacts ◽  
Post Vaccination ◽  
Vaccination Strategies ◽  
Contact Patterns ◽  
Effect Of Age

AbstractBackgroundAs the availability of COVID-19 vaccines, it is badly needed to develop vaccination guidelines to prioritize the vaccination delivery in order to effectively stop COVID-19 epidemic and minimize the loss.MethodsWe evaluated the effect of age-specific vaccination strategies on the number of infections and deaths using an SEIR model, considering the age structure and social contact patterns for different age groups for each of different countries.ResultsIn general, the vaccination priority should be given to those younger people who are active in social contacts to minimize the number of infections; while the vaccination priority should be given to the elderly to minimize the number of deaths. But this principle may not always apply when the interaction of age structure and age-specific social contact patterns is complicated. Partially reopening schools, workplaces or households, the vaccination priority may need to be adjusted accordingly.ConclusionsPrematurely reopening social contacts could initiate a new outbreak or even a new pandemic out of control if the vaccination rate and the detection rate are not high enough. Our result suggests that it requires at least nine months of vaccination before fully reopening social contacts in order to avoid a new pandemic.

scholarly journals Adherence to COVID-19 Preventive Measures in Mozambique: Two Consecutive Online Surveys

2021 ◽  
Vol 18 (3) ◽  
pp. 1091
Author(s):  
António Júnior ◽  
Janeth Dula ◽  
Sérgio Mahumane ◽  
Olivier Koole ◽  
Sónia Enosse ◽  
...  
Keyword(s):  
Online Survey ◽  
Preventive Measures ◽  
Compliance Rate ◽  
Face Mask ◽  
Healthcare Sector ◽  
Low Grade ◽  
Cross Sectional ◽  
Preventive Behaviour ◽  
The Face ◽  
Definition Of

We assessed adherence to government recommendations implemented shortly after the introduction of COVID-19 in Mozambique in March 2020, through two online cross-sectional surveys in April and June 2020. We quantified adherence to preventive measures by a composite score comprising of five measures: physical distancing, face mask use, hand hygiene, cough hygiene, and avoidance of touching the face. 3770 and 1115 persons participated in the first and second round respectively. Wearing face masks, regular handwashing and cough hygiene all reached compliance rates of over 90% while physical distancing and avoiding to touch the face reached a compliance rate of 80–90%. A multivariable model investigating factors associated with adherence found that being older, more educated, and belonging to the healthcare sector increased the odds for higher adherence. Private workers and retired people, respondents receiving COVID-19 information through social media, and those who reported flu-like symptoms were less likely to adhere. 6% of respondents reported flu-like symptoms which aligned with the WHO clinical definition of COVID-19, suggesting low level community transmission. In conclusion, most respondents in this online survey in Mozambique complied well with strategies to prevent COVID-19. Whether the good preventive behaviour explains the low grade COVID-19 transmission requires further study.

scholarly journals Face masks to prevent transmission of respiratory diseases: Systematic review and meta-analysis of randomized controlled trials*

2020 ◽  
Author(s):  
Hanna M. Ollila ◽  
Markku Partinen ◽  
Jukka Koskela ◽  
Riikka Savolainen ◽  
Anna Rotkirch ◽  
...  
Keyword(s):  
Systematic Review ◽  
Randomized Controlled Trials ◽  
Respiratory Infections ◽  
Meta Analysis ◽  
Age Groups ◽  
Face Mask ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
The Face ◽  
Intent To Treat

AbstractObjectiveTo examine the effect of face mask intervention in respiratory infections across different exposure settings and age groups.DesignSystematic review and meta-analysis.Data sourcesPubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science were searched for randomized controlled trials investigating the effect of face masks on respiratory infections published by November 18th 2020. Our reporting follows the PRISMA guidelines.Eligibility criteria for selecting studiesRandomized controlled trials investigating the effect of face masks in respiratory infections and influenza-like illness across different exposure settings and age groups. Two reviewers independently performed the search, extracted the data, and assessed the risk of bias. A random effects meta-analysis with risk ratio, risk difference, and number needed to treat were performed. Findings in exposure settings, age groups, and role of non-compliance were examined using a subgroup analysis.ResultsTotal of 17 studies were included, with N = 11, 601 individuals in intervention and N = 10, 286 in the control group with follow-up duration from 4 days to 19 months). 14 trials included adults (and children) and 3 included children only. 12 studies suffered from non-compliance in the treatment arm and 11 in the control arm. All studies were intent-to-treat analyses, and, thus, non-compliance can bias individual intent-to-treat estimates towards zero. Four out of seventeen studies supported use of face masks. A meta-analysis of all 17 studies found no association between face mask intervention and respiratory infections (RR = 0.9046 [0.777 - 1.053], p = 0.196, p fixed effect = 0.0006). However, a meta-analysis using odds ratios adjusted for age, sex, and vaccination (when available) suggests protective effect of the face mask intervention (17 studies, OR = 0.850 [0.736 - 0.982], p=0.027). A subgroup meta-analysis among adults with (unadjusted) risk ratios found a decrease in respiratory infections (14 studies, RR = 0.859 [0.750 - 0.983], p = 0.026, and 4 studies with a combined face masks and hand hygiene intervention RR = 0.782 [0.696 - 0.879], p < 0.0001). Finally, the face mask use is also supported by a meta-regression adjusting the effect estimates for non-compliance in the controls (17 studies RR = 0.87 [0.780 - 0.980], p = 0.017).ConclusionOur findings support the use of face masks to prevent respiratory infections.

Psychological Impact of COVID-19 lockdown_PREPRINT

2020 ◽  
Author(s):  
Valerie van Mulukom ◽  
Barbara Muzzulini ◽  
Bastiaan T Rutjens ◽  
Caspar J. Van Lissa ◽  
Miguel Farias
Keyword(s):  
Social Isolation ◽  
Online Survey ◽  
Psychological Impact ◽  
Social Contact ◽  
Anxiety And Depression ◽  
Negative Effects ◽  
Health Crisis ◽  
Public Health Crisis ◽  
Mitigating Factors ◽  
The Usa

This study addressed the psychological impact of the COVID-19 pandemic on mental health and examined factors exacerbating or mitigating the negative effects of lockdown. Results from a large multi-country online survey (N=8,229) showed average elevated levels of anxiety and depression (especially in the USA, UK, and Brazil), associated with feelings of low control and social isolation. Although social isolation increased with the duration of quarantine, it was mitigated by frequent communication with close others. Other mitigating factors include adaptive but not maladaptive coping, and the perception and trust that one’s government is dealing with the outbreak. Taking individual actions to avoid contracting the virus were associated with higher anxiety, except when done professionally by essential workers. We suggest that the psychological detrimental effects of lockdown can be alleviated by maintaining frequent social contact, adaptive coping, and governmental actions which show capability, benevolence, and integrity in managing a public health crisis.

scholarly journals Influence of heterogeneous age-group contact patterns on critical vaccination rates for herd immunity to SARS-CoV-2

2021 ◽  
Author(s):  
Joan Saldana ◽  
Caterina M Scoglio
Keyword(s):  
Vaccination Coverage ◽  
Herd Immunity ◽  
Age Groups ◽  
Social Contact ◽  
Vaccination Strategy ◽  
Primary Concern ◽  
Vaccination Rates ◽  
Contact Patterns ◽  
Group Contact ◽  
Age Structured

Currently, several western countries have more than half of their population fully vaccinated against COVID-19. At the same time, some of them are experiencing a fourth or even a fifth wave of cases, most of them concentrated in sectors of the populations whose vaccination coverage is lower than the average. So, the initial scenario of vaccine prioritization has given way to a new one where achieving herd immunity is the primary concern. Using an age-structured vaccination model with waning immunity, we show that, under a limited supply of vaccines, a vaccination strategy based on minimizing the basic reproduction number allows for the deployment of a number of vaccine doses lower than the one required for maximizing the vaccination coverage. Such minimization is achieved by giving greater protection to those age groups that, for a given social contact pattern, have smaller fractions of susceptible individuals at the endemic equilibrium without vaccination, that is, to those groups that are more vulnerable to infection.

scholarly journals Students’ Perceptions of Verbal and Non-Verbal Communication Behaviors during and after the COVID-19 Pandemic

2021 ◽  
Vol 11 (18) ◽  
pp. 8282
Author(s):  
Gabriel-Mugurel Dragomir ◽  
Marcela Alina Fărcașiu ◽  
Simona Șimon
Keyword(s):  
Interpersonal Communication ◽  
Online Survey ◽  
Face Mask ◽  
Verbal Communication ◽  
Human Beings ◽  
Communication Behaviors ◽  
Personal Lives ◽  
The Face

Aiming at shedding light on the implications the COVID-19 pandemic has had on the students’ social and personal lives, this study has focused on the verbal and non-verbal communication and on the surveyees’ personal lives during the pandemic as well as on the perspective of changing their communication behaviors after the pandemic. The 409 respondents, students at Politehnica University of Timisoara, took part in a survey, conducted between 1 April and 30 May 2021, that was posted on isondaje.ro, a Romanian online survey platform. The research has suggested the following results: the adjustment of the verbal communication by speaking in a more articulated manner or more loudly; the overuse of the upper part of the face to compensate for the concealed parts of the face due to face mask wearing; the analysis of the factors underlying the respondents’ actions, i.e., relational attitudes, various greeting forms, various non-verbal reactions, which are aspects that are likely to change even after the pandemic. The results have also presented the changes that interpersonal communication could go through under the pressure of the restrictions imposed by the pandemic, but also the ways through which people try to protect their most valuable asset, i.e., communication, which defines humanity and makes us unique as human beings.

scholarly journals Social contact patterns among employees in 3 U.S. companies during early phases of the COVID-19 pandemic, April to June 2020

2020 ◽  
Author(s):  
Moses C. Kiti ◽  
Obianuju G. Aguolu ◽  
Carol Y. Liu ◽  
Ana R. Mesa ◽  
Rachel Regina ◽  
...  
Keyword(s):  
Race And Ethnicity ◽  
Control Strategies ◽  
Age Groups ◽  
Social Contact ◽  
The United States ◽  
Median Number ◽  
Cross Sectional ◽  
Contact Patterns ◽  
The Uk ◽  
Spread Of Infection

2.AbstractImportanceDevising control strategies against diseases such as COVID-19 require understanding of contextual social mixing and contact patterns. There has been no standardized multi-site social contact study conducted in workplace settings in the United States that can be used to broadly inform pandemic preparedness policy in these settings.ObjectiveThe study aimed to characterize the patterns of social contacts and mixing across workplace environments, including on-site or when teleworking.DesignThis was a cross-sectional non-probability survey that used standardized social contact diaries to collect data. Employees were requested to record their physical and non-physical contacts in a diary over two consecutive days, documented at the end of each day. Employees from each company were enrolled through email and electronic diaries sent as individual links. Data were collected from April to June 2020.SettingTwo multinational consulting companies and one university administrative department, all located in Georgia, USA.ParticipantsEmployees opted into the study by accepting the invitation on a link sent via email.Main OutcomeThe outcome was median number of contacts per person per day. This was stratified by day of data collection, age, sex, race and ethnicity.ResultsOf 3,835 employees approached, 357 (9.3%) completed the first day of contact diary of which 304 completed both days of contact diary. There was a median of 2 contacts (IQR: 1-4, range: 0-21) per respondent on both day one and two. The majority (55%) of contacts involved conversation only, occurred at home (64%), and cumulatively lasted more than 4 hours (38%). Most contacts were repeated, and within same age groups, though participants aged 30-59 years reported substantial inter-generational mixing with children.ConclusionParticipating employees in 3 surveyed workplaces reported few contacts, similar to studies from the UK and China when shelter-in-place orders were in effect during the pandemic. Many contacts were repeated which may limit the spread of infection. Future rounds are planned to assess changes in contact patterns when employees resume work in the office after the lockdown due to COVID-19 pandemic.

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