scholarly journals A viral perspective on worldwide non-pharmaceutical interventions against COVID-19

2020 ◽  
Author(s):  
Jean-Philippe Rasigade ◽  
Anaïs Barray ◽  
Julie Teresa Shapiro ◽  
Charlène Coquisart ◽  
Yoann Vigouroux ◽  
...  
Keyword(s):  
Large Scale ◽  
Reproduction Number ◽  
Cumulative Effect ◽  
Epidemiological Data ◽  
Time And Space ◽  
Minimal Set ◽  
Genomic Divergence ◽  
The Impact ◽  
Pharmaceutical Interventions

AbstractQuantifying the effectiveness of large-scale non-pharmaceutical interventions (NPIs) against COVID-19 is critical to adapting responses against future waves of the pandemic. Most studies of NPIs thus far have relied on epidemiological data. Here, we report the impact of NPIs on the evolution of SARS-CoV-2, taking the perspective of the virus. We examined how variations through time and space of SARS-CoV-2 genomic divergence rates, which reflect variations of the epidemic reproduction number Rt, can be explained by NPIs and combinations thereof. Based on the analysis of 5,198 SARS-CoV-2 genomes from 57 countries along with a detailed chronology of 9 non-pharmaceutical interventions during the early epidemic phase up to May 2020, we find that home containment (35% Rt reduction) and education lockdown (26%) had the strongest predicted effectiveness. To estimate the cumulative effect of NPIs, we modelled the probability of reducing Rt below 1, which is required to stop the epidemic, for various intervention combinations and initial Rt values. In these models, no intervention implemented alone was sufficient to stop the epidemic for Rt’s above 2 and all interventions combined were required for Rt’s above 3. Our approach can help inform decisions on the minimal set of NPIs required to control the epidemic depending on the current Rt value.

scholarly journals A viral perspective on worldwide non-pharmaceutical interventions against COVID-19

2020 ◽  
Author(s):  
Jean-Philippe Rasigade ◽  
Anaïs Barray ◽  
Julie Teresa Shapiro ◽  
Charlène Coquisart ◽  
Yoann Vigouroux ◽  
...  
Keyword(s):  
Large Scale ◽  
Reproduction Number ◽  
Cumulative Effect ◽  
Epidemiological Data ◽  
Time And Space ◽  
Minimal Set ◽  
Genomic Divergence ◽  
The Impact ◽  
Pharmaceutical Interventions

Abstract Quantifying the effectiveness of large-scale non-pharmaceutical interventions (NPIs) against COVID-19 is critical to adapting responses against future waves of the pandemic. Most studies of NPIs thus far have relied on epidemiological data. Here, we report the impact of NPIs on the evolution of SARS-CoV-2, taking the perspective of the virus. We examined how variations through time and space of SARS-CoV-2 genomic divergence rates, which reflect variations of the epidemic reproduction number Rt, can be explained by NPIs and combinations thereof. Based on the analysis of 5,198 SARS-CoV-2 genomes from 57 countries along with a detailed chronology of 9 non-pharmaceutical interventions during the early epidemic phase up to May 2020, we find that home containment (35% Rt reduction) and education lockdown (26%) had the strongest predicted effectiveness. To estimate the cumulative effect of NPIs, we modelled the probability of reducing Rt below 1, which is required to stop the epidemic, for various intervention combinations and initial Rt values. In these models, no intervention implemented alone was sufficient to stop the epidemic for Rt’s above 2 and all interventions combined were required for Rt’s above 3. Our approach can help inform decisions on the minimal set of NPIs required to control the epidemic depending on the current Rt value.

scholarly journals Determining the optimal strategy for reopening schools, work and society in the UK: balancing earlier opening and the impact of test and trace strategies with the risk of occurrence of a secondary COVID-19 pandemic wave

2020 ◽  
Author(s):  
Jasmina Panovska-Griffiths ◽  
Cliff Kerr ◽  
Robyn Margaret Stuart ◽  
Dina Mistry ◽  
Daniel Klein ◽  
...  
Keyword(s):  
Large Scale ◽  
Reproduction Number ◽  
Epidemiological Data ◽  
Contact Tracing ◽  
Cumulative Number ◽  
Social Distancing ◽  
Uk Government ◽  
The Uk ◽  
The Impact ◽  
Pandemic Wave

Background In order to slow down the spread of SARS-CoV-2, the virus causing the COVID-19 pandemic, the UK government has imposed strict physical distancing (lockdown) measures including school 'dismissals' since 23 March 2020. As evidence is emerging that these measures may have slowed the spread of the pandemic, it is important to assess the impact of any changes in strategy, including scenarios for school reopening and broader relaxation of social distancing. This work uses an individual-based model to predict the impact of a suite of possible strategies to reopen schools in the UK, including that currently proposed by the UK government. Methods We use Covasim, a stochastic agent-based model for transmission of COVID-19, calibrated to the UK epidemic. The model describes individuals' contact networks stratified as household, school, work and community layers, and uses demographic and epidemiological data from the UK. We simulate a range of different school reopening strategies with a society-wide relaxation of lockdown measures and in the presence of different non-pharmaceutical interventions, to estimate the number of new infections, cumulative cases and deaths, as well as the effective reproduction number with different strategies. To account for uncertainties within the stochastic simulation, we also simulated different levels of infectiousness of children and young adults under 20 years old compared to older ages. Findings We found that with increased levels of testing of people (between 25% and 72% of symptomatic people tested at some point during an active COVID-19 infection depending on scenarios) and effective contact-tracing and isolation for infected individuals, an epidemic rebound may be prevented across all reopening scenarios, with the effective reproduction number (R) remaining below one and the cumulative number of new infections and deaths significantly lower than they would be if testing did not increase. If UK schools reopen in phases from June 2020, prevention of a second wave would require testing 51% of symptomatic infections, tracing of 40% of their contacts, and isolation of symptomatic and diagnosed cases. However, without such measures, reopening of schools together with gradual relaxing of the lockdown measures are likely to induce a secondary pandemic wave, as are other scenarios for reopening. When infectiousness of <20 year olds was varied from 100% to 50% of that of older ages, our findings remained unchanged. Interpretation To prevent a secondary COVID-19 wave, relaxation of social distancing including reopening schools in the UK must be implemented alongside an active large-scale population-wide testing of symptomatic individuals and effective tracing of their contacts, followed by isolation of symptomatic and diagnosed individuals. Such combined measures have a greater likelihood of controlling the transmission of SARS-CoV-2 and preventing a large number of COVID-19 deaths than reopening schools and society with the current level of implementation of testing and isolation of infected individuals.

scholarly journals The effects of non-pharmaceutical interventions on SARS-CoV-2 transmission in different socioeconomic populations in Kuwait: a modeling study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fatima Khadadah ◽  
Abdullah A. Al-Shammari ◽  
Ahmad Alhashemi ◽  
Dari Alhuwail ◽  
Bader Al-Saif ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Reproduction Number ◽  
Transmission Model ◽  
Socioeconomic Groups ◽  
Before And After ◽  
Cross Transmission ◽  
Community Transmission ◽  
The Impact ◽  
Pharmaceutical Interventions ◽  
The Basic Reproduction Number

Abstract Background Aggressive non-pharmaceutical interventions (NPIs) may reduce transmission of SARS-CoV-2. The extent to which these interventions are successful in stopping the spread have not been characterized in countries with distinct socioeconomic groups. We compared the effects of a partial lockdown on disease transmission among Kuwaitis (P1) and non-Kuwaitis (P2) living in Kuwait. Methods We fit a modified metapopulation SEIR transmission model to reported cases stratified by two groups to estimate the impact of a partial lockdown on the effective reproduction number ($$ {\mathcal{R}}_e $$ R e ). We estimated the basic reproduction number ($$ {\mathcal{R}}_0 $$ R 0 ) for the transmission in each group and simulated the potential trajectories of an outbreak from the first recorded case of community transmission until 12 days after the partial lockdown. We estimated $$ {\mathcal{R}}_e $$ R e values of both groups before and after the partial curfew, simulated the effect of these values on the epidemic curves and explored a range of cross-transmission scenarios. Results We estimate $$ {\mathcal{R}}_e $$ R e at 1·08 (95% CI: 1·00–1·26) for P1 and 2·36 (2·03–2·71) for P2. On March 22nd, $$ {\mathcal{R}}_e $$ R e for P1 and P2 are estimated at 1·19 (1·04–1·34) and 1·75 (1·26–2·11) respectively. After the partial curfew had taken effect, $$ {\mathcal{R}}_e $$ R e for P1 dropped modestly to 1·05 (0·82–1·26) but almost doubled for P2 to 2·89 (2·30–3·70). Our simulated epidemic trajectories show that the partial curfew measure greatly reduced and delayed the height of the peak in P1, yet significantly elevated and hastened the peak in P2. Modest cross-transmission between P1 and P2 greatly elevated the height of the peak in P1 and brought it forward in time closer to the peak of P2. Conclusion Our results indicate and quantify how the same lockdown intervention can accentuate disease transmission in some subpopulations while potentially controlling it in others. Any such control may further become compromised in the presence of cross-transmission between subpopulations. Future interventions and policies need to be sensitive to socioeconomic and health disparities.

Overburdened Gauls: the case of Florus and Sacrovir’s revolt of 21 CE

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jared Kreiner
Keyword(s):  
Interest Rates ◽  
Large Scale ◽  
Cumulative Effect ◽  
Short Term ◽  
Local Economies ◽  
Scale Resistance ◽  
Military Campaigns ◽  
The Impact

Abstract In 21 CE, a series of localized movements broke out in Gallia Comata due to heavy debts among provincials according to Tacitus. Modern scholars have long argued that the indebtedness occurred because of rising interest rates, resulting from dwindling currency in circulation after decades of free-spending following Augustus’ victory at Actium, and that Gallic communities were subjected to an additional tribute to support the wars of Germanicus (14–16 CE), which continued unabated after the wars and pushed Gauls beyond their means. These claims are misguided, however, in that there is no certain evidence of a special tax to support Germanicus’ wars and that the argument for a dwindling circulation of currency in Gaul falters under closer inspection. Rather, the pressing statal and military needs imposed on communities in Gallia Comata after 9 CE on top of routine exactions could significantly increase burden levels levied on provincial populations, thus contributing to rising debts. Through examining how Roman logistics and conscription operated in this period, it is possible to trace how populations were impacted by such demands and which communities were most heavily affected by them, too. Individually, the impact of each factor is unlikely to have been burdensome enough to have caused large-scale resistance, it is only the cumulative effect that these explanations had on top of routine Roman extraction schemes that could create the conditions for this revolt. This paper argues that in extraordinary circumstances, such as the period after the Varian Disaster for Gallia Comata, the costs of supporting military campaigns places real short-term strains on local economies, which creates the conditions for revolt. The benefit of this approach is that it may explain other episodes of anti-fiscal resistance that broke out during or within a decade of wars in neighboring regions.

scholarly journals The effects of non-pharmaceutical interventions on SARS-CoV-2 transmission in different socioeconomic populations in Kuwait: A modelling study

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Fatima Khadadah ◽  
Abdullah A. Al-Shammari ◽  
Ahmad Alhashemi ◽  
Dari Alhuwail ◽  
Bader Al-Saif ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Reproduction Number ◽  
Public Health Intervention ◽  
Population Level ◽  
Socioeconomic Groups ◽  
Before And After ◽  
Cross Transmission ◽  
Community Transmission ◽  
The Impact ◽  
Pharmaceutical Interventions

Background: Aggressive non-pharmaceutical interventions (NPIs) may reduce transmission of SARS-CoV2. The extent to which these interventions are successful in stopping the spread have not been characterized in countries with distinct socioeconomic groups. We compared the effects of a partial lockdown on disease transmission among Kuwaitis (P1) and non-Kuwaitis (P2) living in Kuwait. Methods: We fit a metapopulation Susceptible-Exposed-Infectious-Recovered (SEIR) model to reported cases stratified by two groups to estimate the impact of a lockdown on the effective reproduction number (Re). We estimated the basic reproduction number (R0) for the transmission in each group and simulated the potential trajectories of an outbreak from the first recorded case of community transmission until 12 days after the lockdown. We estimated R­e values of both groups before and after the lockdown, simulated the effect of these values on epidemic curves and explored a range of cross-transmission scenarios. Results: We estimate R0 at 1·06 (95% CI: 1·05-1·28) for P1 and 1·83 (1·58-2·33) for P2. On March 22nd, Re for P1 and P2 are estimated at 1·13 (1·07-1·17) and 1·38 (1·25-1·63) respectively. After the curfew had taken effect, Re for P1 dropped modestly to 1·04 (1·02-1·06) but almost doubled for P2 to 2·47 (1·98-3·45). Our simulated epidemic trajectories show that the partial curfew measure modestly reduced and delayed the height of the peak in P1, yet significantly elevated and hastened the peak in P2. Modest cross-transmission from P2 to P1 elevated the height of the peak in P1 and brought it forward in time closer to the peak of P2.    Conclusion: Our results demonstrate that a lockdown can reduce SARS-CoV2 transmission in one subpopulation but accelerate it in another. At the population level, the consequences of lockdowns may vary across the socioeconomic spectrum. Any public health intervention needs to be sensitive to disparities within populations.

scholarly journals Novel transdisciplinary methodology for cross-sectional analysis of snakebite epidemiology at national scale

2021 ◽  
Vol 15 (2) ◽  
pp. e0009023
Author(s):  
Gabriel Alcoba ◽  
Carlos Ochoa ◽  
Sara Babo Martins ◽  
Rafael Ruiz de Castañeda ◽  
Isabelle Bolon ◽  
...  
Keyword(s):  
Large Scale ◽  
Survey Methodology ◽  
Neglected Tropical Diseases ◽  
Animal Health ◽  
Epidemiological Data ◽  
World Health ◽  
Primary Data ◽  
Cross Sectional ◽  
High Resolution Satellite Images ◽  
The Impact

Background Worldwide, it is estimated that snakes bite 4.5–5.4 million people annually, 2.7 million of which are envenomed, and 81,000–138,000 die. The World Health Organization reported these estimates and recognized the scarcity of large-scale, community-based, epidemiological data. In this context, we developed the “Snake-Byte” project that aims at (i) quantifying and mapping the impact of snakebite on human and animal health, and on livelihoods, (ii) developing predictive models for medical, ecological and economic indicators, and (iii) analyzing geographic accessibility to healthcare. This paper exclusively describes the methodology we developed to collect large-scale primary data on snakebite in humans and animals in two hyper-endemic countries, Cameroon and Nepal. Methodology/Principal findings We compared available methods on snakebite epidemiology and on multi-cluster survey development. Then, in line with those findings, we developed an original study methodology based on a multi-cluster random survey, enhanced by geospatial, One Health, and health economics components. Using a minimum hypothesized snakebite national incidence of 100/100,000/year and optimizing design effect, confidence level, and non-response margin, we calculated a sample of 61,000 people per country. This represented 11,700 households in Cameroon and 13,800 in Nepal. The random selection with probability proportional to size generated 250 clusters from all Cameroonian regions and all Nepalese Terai districts. Our household selection methodology combined spatial randomization and selection via high-resolution satellite images. After ethical approval in Switerland (CCER), Nepal (BPKIHS), and Cameroon (CNERSH), and informed written consent, our e-questionnaires included geolocated baseline demographic and socio-economic characteristics, snakebite clinical features and outcomes, healthcare expenditure, animal ownership, animal outcomes, snake identification, and service accessibility. Conclusions/Significance This novel transdisciplinary survey methodology was subsequently used to collect countrywide snakebite envenoming data in Nepal and Cameroon. District-level incidence data should help health authorities to channel antivenom and healthcare allocation. This methodology, or parts thereof, could be easily adapted to other countries and to other Neglected Tropical Diseases.

scholarly journals Assessing the impact of adherence to Non-pharmaceutical interventions and indirect transmission on the dynamics of COVID-19: a mathematical modelling study

2021 ◽  
Author(s):  
Sarafa A. Iyaniwura ◽  
Musa Rabiu ◽  
Jummy F. David ◽  
Jude D. Kong
Keyword(s):  
Public Health ◽  
Reproduction Number ◽  
Health Policies ◽  
Public Health Policies ◽  
Indirect Transmission ◽  
Epidemic Size ◽  
Final Epidemic Size ◽  
The Impact ◽  
Size Relation ◽  
Pharmaceutical Interventions

AbstractAdherence to public health policies such as the non-pharmaceutical interventions implemented against COVID-19 plays a major role in reducing infections and controlling the spread of the diseases. In addition, understanding the transmission dynamics of the disease is also important in order to make and implement efficient public health policies. In this paper, we developed an SEIR-type compartmental model to assess the impact of adherence to COVID-19 non-pharmaceutical interventions and indirect transmission on the dynamics of the disease. Our model considers both direct and indirect transmission routes and stratifies the population into two groups: those that adhere to COVID-19 non-pharmaceutical interventions (NPIs) and those that do not adhere to the NPIs. We compute the control reproduction number and the final epidemic size relation for our model and study the effect of different parameters of the model on these quantities. Our results show that direct transmission has more effect on the reproduction number and final epidemic size, relative to indirect transmission. In addition, we showed that there is a significant benefit in adhering to the COVID-19 NPIs.

scholarly journals Synergetic measures needed to control infection waves and contain SARS-CoV-2 transmission

2021 ◽  
Author(s):  
Hang Su ◽  
Yafang Cheng ◽  
Ulrich Poeschl
Keyword(s):  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Scientific Discourse ◽  
Protective Measure ◽  
Protective Measures ◽  
Vaccination Rates ◽  
The Public ◽  
Individual Measure ◽  
The Impact ◽  
Pharmaceutical Interventions

The public and scientific discourse on how to mitigate the COVID-19 pandemic is often focused on the impact of individual protective measures, in particular on immunization by vaccination. In view of changing virus variants and conditions, however, it seems not clear if vaccination or any other single protective measure alone may suffice to contain the transmission of SARS-CoV-2. Here, we investigate the effectiveness and synergies of vaccination and different non-pharmaceutical interventions such as universal masking (surgical, N95/FFP2), distancing & ventilation, contact reduction, and testing & isolation as a function of compliance in the population. We find that it would be difficult to contain SARS-CoV-2 transmission by any individual measure as currently available under realistic conditions. Instead, we show how multiple synergetic measures can be and have to be combined to decrease and keep the effective reproduction number (Re) below unity, even for virus variants with increased basic reproduction number (R0). We suggest that the presented approach and results can be used to design and communicate efficient strategies for mitigating the COVID-19 pandemic, depending on R0 as well as the efficacy and compliance achieved with each protective measure. At vaccination rates around 70%, the combination and synergies of universal masking, distancing & ventilation, and testing & isolation with moderate compliances around 30% appear well suited to keep Re below 1 and prevent or suppress infection waves. Higher compliance or additional measures like contact reductions (confinement/lockdown) are required to effectively and swiftly break intense waves of infection. For schools, we find that the transmission of SARS-CoV-2 can be contained by 2-3 tests per week combined with distancing & ventilation and masking.

scholarly journals Large-scale Lassa fever outbreaks in Nigeria: quantifying the association between disease reproduction number and local rainfall

2020 ◽  
Vol 148 ◽  
Author(s):  
Shi Zhao ◽  
Salihu S. Musa ◽  
Hao Fu ◽  
Daihai He ◽  
Jing Qin
Keyword(s):  
Spatial Heterogeneity ◽  
Large Scale ◽  
Reproduction Number ◽  
Growth Models ◽  
Random Effect ◽  
Lassa Fever ◽  
Viral Haemorrhagic Fever ◽  
Average Monthly Rainfall ◽  
Sub Saharan ◽  
The Impact

Abstract Lassa fever (LF) is increasingly recognised as an important rodent-borne viral haemorrhagic fever presenting a severe public health threat to sub-Saharan West Africa. In 2017–18, LF caused an unprecedented epidemic in Nigeria and the situation was worsening in 2018–19. This work aims to study the epidemiological features of epidemics in different Nigerian regions and quantify the association between reproduction number (R) and state rainfall. We quantify the infectivity of LF by the reproduction numbers estimated from four different growth models: the Richards, three-parameter logistic, Gompertz and Weibull growth models. LF surveillance data are used to fit the growth models and estimate the Rs and epidemic turning points (τ) in different regions at different time periods. Cochran's Q test is further applied to test the spatial heterogeneity of the LF epidemics. A linear random-effect regression model is adopted to quantify the association between R and state rainfall with various lag terms. Our estimated Rs for 2017–18 (1.33 with 95% CI 1.29–1.37) was significantly higher than those for 2016–17 (1.23 with 95% CI: (1.22, 1.24)) and 2018–19 (ranged from 1.08 to 1.36). We report spatial heterogeneity in the Rs for epidemics in different Nigerian regions. We find that a one-unit (mm) increase in average monthly rainfall over the past 7 months could cause a 0.62% (95% CI 0.20%–1.05%)) rise in R. There is significant spatial heterogeneity in the LF epidemics in different Nigerian regions. We report clear evidence of rainfall impacts on LF epidemics in Nigeria and quantify the impact.

scholarly journals Vaccinations, Mobility and COVID-19 Transmission

2021 ◽  
Vol 19 (1) ◽  
pp. 97
Author(s):  
Jianfeng Guo ◽  
Chao Deng ◽  
Fu Gu
Keyword(s):  
Structural Equation Modeling ◽  
Structural Equation ◽  
Large Scale ◽  
Equation Modeling ◽  
World Population ◽  
Human Behaviors ◽  
The World ◽  
Positive Correlations ◽  
The Impact ◽  
Pharmaceutical Interventions

In order to prevent the spread of coronavirus disease 2019 (COVID-19), 52.4% of the world population had received at least one dose of a vaccine at17 November 2021, but little is known about the non-pharmaceutical aspect of vaccination. Here we empirically examine the impact of vaccination on human behaviors and COVID-19 transmission via structural equation modeling. The results suggest that, from a non-pharmaceutical perspective, the effectiveness of COVID-19 vaccines is related to human behaviors, in this case, mobility; vaccination slows the spread of COVID-19 in the regions where vaccination is negatively related to mobility, but such an effect is not observed in the regions where vaccination and mobility have positive correlations. This article highlights the significance of mobility in realizing the effectiveness of COVID-19 vaccines; even with large-scale vaccination, non-pharmaceutical interventions, such as social distancing, are still required to contain the transmission of COVID-19.

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