Travel-related control measures to contain the COVID-19 pandemic: a rapid review

Effectiveness of non-pharmaceutical interventions as implemented in the UK during the COVID-19 pandemic: a rapid review

BACKGROUND

Although non-pharmaceutical inventions (NPIs) were used globally to control the spread of COVID-19, their effectiveness remains uncertain. We aimed to assess the evidence on NPIs as implemented in the UK, to allow public health bodies to prepare for future pandemics.

METHODS

We used rapid systematic methods (search date: January 2024) to identify, critically appraise and synthesize interventional, observational and modelling studies reporting on NPI effectiveness in the UK.

RESULTS

Eighty-five modelling, nine observational and three interventional studies were included. Modelling studies had multiple quality issues; six of the 12 non-modelling studies were high quality. The best available evidence was for test and release strategies for case contacts (moderate certainty), which was suggestive of a protective effect. Although evidence for school-related NPIs and universal lockdown was also suggestive of a protective effect, this evidence was considered low certainty. Evidence certainty for the remaining NPIs was very low or inconclusive.

CONCLUSION

The validity and reliability of evidence on the effectiveness of NPIs as implemented in the UK during the COVID-19 pandemic is weak. To improve evidence generation and support decision-making during future pandemics or other public health emergencies, it is essential to build evaluation into the design of public health interventions.

Impact of non-pharmaceutical interventions on COVID-19 incidence and deaths: cross-national natural experiment in 32 European countries

PURPOSE

Non-pharmaceutical interventions (NPIs) have been the cornerstone of COVID-19 pandemic control, but evidence on their effectiveness varies according to the methods and approaches taken to empirical analysis. We analysed the impact of NPIs on incident SARS-CoV-2 across 32 European countries (March-December 2020) using two NPI trackers: the Corona Virus Pandemic Policy Monitor - COV-PPM, and the Oxford Covid-19 Government Response Tracker - OxCGRT.

METHODS

NPIs were summarized through principal component analysis into three sets, stratified by two waves (C1-C3, weeks 5-25, and C4-C6, weeks 35-52). Longitudinal, multi-level mixed-effects negative binomial regression models were fitted to estimate incidence rate ratios for cases and deaths considering different time-lags and reverse causation (i.e. changing incidence causing NPIs), stratified by waves and geographical regions (Western, Eastern, Northern, Southern, Others).

RESULTS

During the first wave, restrictions on movement/mobility, public transport, public events, and public spaces (C1) and healthcare system improvements, border closures and restrictions to public institutions (C2) were associated with a reduction in SARS-CoV-2 incidence after 28 and 35-days. Mask policies (C3) were associated with a reduction in SARS-CoV-2 incidence (except after 35-days). During wave 1, C1 and C2 were associated with a decrease in deaths after 49-days and C3 after 21, 28 and 35-days. During wave 2, restrictions on movement/mobility, public transport and healthcare system improvements (C5) were also associated with a decrease in SARS-CoV-2 cases and deaths across all countries.

CONCLUSION

In the absence of pre-existing immunity, vaccines or treatment options, our results suggest that the observed implementation of different categories of NPIs, showed varied associations with SARS-CoV-2 incidence and deaths across regions, and varied associations across waves. These relationships were consistent across components of NPIs derived from two policy trackers (CoV-PPM and OxCGRT).

Measures implemented in the school setting to contain the COVID-19 pandemic

BACKGROUND

More than 767 million coronavirus 2019 (COVID-19) cases and 6.9 million deaths with COVID-19 have been recorded as of August 2023. Several public health and social measures were implemented in schools to contain the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and prevent onward transmission. We built upon methods from a previous Cochrane review to capture current empirical evidence relating to the effectiveness of school measures to limit SARS-CoV-2 transmission.

OBJECTIVES

To provide an updated assessment of the evidence on the effectiveness of measures implemented in the school setting to keep schools open safely during the COVID-19 pandemic.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register, Educational Resources Information Center, World Health Organization (WHO) COVID-19 Global literature on coronavirus disease database, and the US Department of Veterans Affairs Evidence Synthesis Program COVID-19 Evidence Reviews on 18 February 2022.

SELECTION CRITERIA

Eligible studies focused on measures implemented in the school setting to contain the COVID-19 pandemic, among students (aged 4 to 18 years) or individuals relating to the school, or both. We categorized studies that reported quantitative measures of intervention effectiveness, and studies that assessed the performance of surveillance measures as either 'main' or 'supporting' studies based on design and approach to handling key confounders. We were interested in transmission-related outcomes and intended or unintended consequences.

DATA COLLECTION AND ANALYSIS

Two review authors screened titles, abstracts and full texts. We extracted minimal data for supporting studies. For main studies, one review author extracted comprehensive data and assessed risk of bias, which a second author checked. We narratively synthesized findings for each intervention-comparator-outcome category (body of evidence). Two review authors assessed certainty of evidence.

MAIN RESULTS

The 15 main studies consisted of measures to reduce contacts (4 studies), make contacts safer (7 studies), surveillance and response measures (6 studies; 1 assessed transmission outcomes, 5 assessed performance of surveillance measures), and multicomponent measures (1 study). These main studies assessed outcomes in the school population (12), general population (2), and adults living with a school-attending child (1). Settings included K-12 (kindergarten to grade 12; 9 studies), secondary (3 studies), and K-8 (kindergarten to grade 8; 1 study) schools. Two studies did not clearly report settings. Studies measured transmission-related outcomes (10), performance of surveillance measures (5), and intended and unintended consequences (4). The 15 main studies were based in the WHO Regions of the Americas (12), and the WHO European Region (3). Comparators were more versus less intense measures, single versus multicomponent measures, and measures versus no measures. We organized results into relevant bodies of evidence, or groups of studies relating to the same 'intervention-comparator-outcome' categories. Across all bodies of evidence, certainty of evidence ratings limit our confidence in findings. Where we describe an effect as 'beneficial', the direction of the point estimate of the effect favours the intervention; a 'harmful' effect does not favour the intervention and 'null' shows no effect either way. Measures to reduce contact (4 studies) We grouped studies into 21 bodies of evidence: moderate- (10 bodies), low- (3 bodies), or very low-certainty evidence (8 bodies). The evidence was very low to moderate certainty for beneficial effects of remote versus in-person or hybrid teaching on transmission in the general population. For students and staff, mostly harmful effects were observed when more students participated in remote teaching. Moderate-certainty evidence showed that in the general population there was probably no effect on deaths and a beneficial effect on hospitalizations for remote versus in-person teaching, but no effect for remote versus hybrid teaching. The effects of hybrid teaching, a combination of in-person and remote teaching, were mixed. Very low-certainty evidence showed that there may have been a harmful effect on risk of infection among adults living with a school student for closing playgrounds and cafeterias, a null effect for keeping the same teacher, and a beneficial effect for cancelling extracurricular activities, keeping the same students together and restricting entry for parents and caregivers. Measures to make contact safer (7 studies) We grouped studies into eight bodies of evidence: moderate- (5 bodies), and low-certainty evidence (3 bodies). Low-certainty evidence showed that there may have been a beneficial effect of mask mandates on transmission-related outcomes. Moderate-certainty evidence showed full mandates were probably more beneficial than partial or no mandates. Evidence of a beneficial effect of physical distancing on risk of infection among staff and students was mixed. Moderate-certainty evidence showed that ventilation measures probably reduce cases among staff and students. One study (very low-certainty evidence) found that there may be a beneficial effect of not sharing supplies and increasing desk space on risk of infection for adults living with a school student, but showed there may be a harmful effect of desk shields. Surveillance and response measures (6 studies) We grouped studies into seven bodies of evidence: moderate- (3 bodies), low- (1 body), and very low-certainty evidence (3 bodies). Daily testing strategies to replace or reduce quarantine probably helped to reduce missed school days and decrease the proportion of asymptomatic school contacts testing positive (moderate-certainty evidence). For studies that assessed the performance of surveillance measures, the proportion of cases detected by rapid antigen detection testing ranged from 28.6% to 95.8%, positive predictive value ranged from 24.0% to 100.0% (very low-certainty evidence). There was probably no onward transmission from contacts of a positive case (moderate-certainty evidence) and replacing or shortening quarantine with testing may have reduced missed school days (low-certainty evidence). Multicomponent measures (1 study) Combining multiple measures may have led to a reduction in risk of infection among adults living with a student (very low-certainty evidence).

AUTHORS' CONCLUSIONS

A range of measures can have a beneficial effect on transmission-related outcomes, healthcare utilization and school attendance. We rated the current findings at a higher level of certainty than the original review. Further high-quality research into school measures to control SARS-CoV-2 in a wider variety of contexts is needed to develop a more evidence-based understanding of how to keep schools open safely during COVID-19 or a similar public health emergency.

Characteristic analysis of China's actions against the COVID-19 in schools and comparison with other countries

BACKGROUND

The outbreak of the COVID-19 poses a great threat to students globally. China has taken steps to keep students from becoming infected for more than 30 months, while other countries have also taken steps. Comparing the intentions, implementation, immediate and long-term effects of these initiatives can shed more light on the care of adolescents in schools.

OBJECTIVE

The focus of the study is to describe the full range of school prevention measures in China, identifying when they work and when they do not. At the same time, some typical measures taken in other countries' schools are presented and compared to provide a comprehensive discussion.

METHODS

This study attempted to combine data comparison, information analysis, policy interpretation, and participatory observation to form a comprehensive analytical network.

RESULTS

China's schools have gone through of lucky periods, safety periods, difficult periods, and crisis periods. These efforts are due to the government's intense control measures, strict accountability of school administrators, frequent nucleic acid testing, widespread vaccination, and widely implemented online learning. In comparison, the measures taken by China are difficult to implement, and the price paid by the government, schools and students needs to be further assessed and reflected upon.

CONCLUSIONS

The virus is able to destroy the school's defence with ease. There should be a consensus among countries for a permanent virus control strategy, but the severity of the various measures needs to be appropriately determined, strict control measures can also have negative effects.

An analysis of WHO's Temporary Recommendations on international travel and trade measures during Public Health Emergencies of International Concern

During Public Health Emergencies of International Concern (PHEICs), The International Health Regulations (IHR) require the WHO to issue Temporary Recommendations on the use of international travel and trade measures. During the COVID-19 pandemic, WHO's initial recommendation against 'any travel or trade restriction' has been questioned, and virtually all countries subsequently used international travel measures. WHO's Recommendations to States Parties also changed over the course of the pandemic. There is a need to understand how WHO's treatment of this issue compared with other PHEICs and why States Parties' actions diverged from WHO's initial Recommendations. This first analysis of WHO's Temporary Recommendations on international travel and trade measures during all seven PHEICs compares the guidance for clarity and consistency in several areas of substance and process. We find that lack of clarity and inconsistency in WHO guidance makes it difficult to interpret and relate back to IHR obligations. Based on this analysis, we offer recommendations to increase consistency and clarity of WHO's guidance on this issue during global health emergencies.

Spatio-temporal dynamic of the COVID-19 epidemic and the impact of imported cases in Rwanda

INTRODUCTION

Africa was threatened by the coronavirus disease 2019 (COVID-19) due to the limited health care infrastructure. Rwanda has consistently used non-pharmaceutical strategies, such as lockdown, curfew, and enforcement of prevention measures to control the spread of COVID-19. Despite the mitigation measures taken, the country has faced a series of outbreaks in 2020 and 2021. In this paper, we investigate the nature of epidemic phenomena in Rwanda and the impact of imported cases on the spread of COVID-19 using endemic-epidemic spatio-temporal models. Our study provides a framework for understanding the dynamics of the epidemic in Rwanda and monitoring its phenomena to inform public health decision-makers for timely and targeted interventions.

RESULTS

The findings provide insights into the effects of lockdown and imported infections in Rwanda's COVID-19 outbreaks. The findings showed that imported infections are dominated by locally transmitted cases. The high incidence was predominant in urban areas and at the borders of Rwanda with its neighboring countries. The inter-district spread of COVID-19 was very limited due to mitigation measures taken in Rwanda.

CONCLUSION

The study recommends using evidence-based decisions in the management of epidemics and integrating statistical models in the analytics component of the health information system.

Factors associated with having COVID-19 among unvaccinated pregnant and non-pregnant women in Metro Manila, Philippines: a multicentre longitudinal cohort study

OBJECTIVE

To determine the potential risk factors associated with having COVID-19 among unvaccinated pregnant and non-pregnant women.

DESIGN

A multicentre prospective cohort study among eligible women in Metro Manila, Philippines, from 2020 to 2022.

SETTING

Five national and local hospital research sites altogether recruited and screened 500 consenting eligible individuals.

PARTICIPANTS

Pregnant and non-pregnant participants meeting the eligibility criteria were admitted for a reverse-transcription PCR determination of SARS-CoV-2, pregnancy testing and ultrasound, and an interview with an administered questionnaire.

EXPOSURES

Primary exposure was pregnancy; secondary exposures involve sociodemographic, lifestyle and obstetric-gynaecologic factors.

OUTCOME MEASURE

Outcome being measured was COVID-19 status.

RESULTS

The significant COVID-19 risk factors were: pregnancy (PR=1.184, 95% CI 1.096, 1.279), having a white-collar job (PR=1.123, 95% CI 1.02, 1.235), travelling abroad (PR=1.369, 95% CI 1.083, 1.173) and being infected by at least one vaccine-preventable disease (VPD) (PR=1.208, 95% CI 1.113, 1.310). Protective factors included having graduate-level education (PR=0.787, 95% CI 0.649, 0.954), immunisation against a VPD (PR=0.795, 95% CI 0.733, 0.862) and practising contraception (PR=0.889, 95% CI 0.824, 0.960).

CONCLUSION

This study is the first in the country to determine the risks influencing COVID-19 infection among unvaccinated pregnant and non-pregnant women. Pregnancy is a significant risk for COVID-19 among women in Metro Manila. Educational attainment and positive health behaviours seem to confer protection. Occupations and activities that increase the frequency of interactions, as well as history of communicable diseases may predispose women to COVID-19. Further studies are needed to elucidate the development of the disease in pregnant women, including the maternal and neonatal effects of COVID-19 via potential vertical mechanisms of transmission.

Metrics of Mobility: Assessing the Impact of COVID-19 on Travel Behavior

The COVID-19 pandemic disrupted typical travel behavior worldwide. In the United States (U.S.), government entities took action to limit its spread through public health messaging to encourage reduced mobility and thus reduce the spread of the virus. Within statewide responses to COVID-19, however, there were different responses locally. Likely some of these variations were a result of individual attitudes toward the government and health messaging, but there is also likely a portion of the effects that were because of the character of the communities. In this research, we summarize county-level characteristics that are known to affect travel behavior for 404 counties in the U.S., and we investigate correlates of mobility between April and September (2020). We do this through application of three metrics that are derived via changepoint analysis-initial post-disruption mobility index, changepoint on restoration of a "new normal," and recovered mobility index. We find that variables for employment sectors are significantly correlated and had large effects on mobility during the pandemic. The state dummy variables are significant, suggesting that counties within the same state behaved more similarly to one another than to counties in different states. Our findings indicate that few travel characteristics that typically correlate with travel behavior are related to pandemic mobility, and that the number of COVID-19 cases may not be correlated with mobility outcomes.

Transportation as a Disease Vector in COVID-19: Border Mobility and Disease Spread

More than a year after COVID-19 was declared a pandemic by the World Health Organization, the U.S.A. and Mexico rank first and fourth, respectively, with regard to the number of deaths. From March 2020, nonessential travelers were not allowed to cross the border into the U.S.A. from Mexico via international land ports of entry, which resulted in a more than 50% decrease in the number of people crossing the border. However, border communities still face a higher number of cases and faster community spread compared with those without international land ports of entry. This paper established an econometric model to understand the effects of cross-border mobility and other socioeconomic parameters on the speed of spread. The model was developed at the U.S. county level using data from all 3,141 counties in the U.S.A. Additionally, a follow-up U.S. county comparative analysis was developed to examine the significance of having a border crossing between the U.S.A. and Mexico for U.S. counties. The findings of the analysis revealed that the variables having a significant effect are as follows: population density; number of people per household; population in the 15-65 age group; median household income; mask use; number of visits to transit stations; number of visits to workplace; overall mobility; and having a border crossing to Mexico within county limits. The comparative analysis found that U.S. counties with border crossings have an average of 123 cases per 1,000 population whereas their counterparts without border crossings only have 90 cases per 1,000 population.

The challenge of estimating the direct and indirect effects of COVID-19 interventions - Toward an integrated economic and epidemiological approach

Decisions on public health measures to contain a pandemic are often based on parameters such as expected disease burden and additional mortality due to the pandemic. Both pandemics and non-pharmaceutical interventions to fight pandemics, however, produce economic, social, and medical costs. The costs are, for example, caused by changes in access to healthcare, social distancing, and restrictions on economic activity. These factors indirectly influence health outcomes in the short- and long-term perspective. In a narrative review based on targeted literature searches, we develop a comprehensive perspective on the concepts available as well as the challenges of estimating the overall disease burden and the direct and indirect effects of COVID-19 interventions from both epidemiological and economic perspectives, particularly during the early part of a pandemic. We review the literature and discuss relevant components that need to be included when estimating the direct and indirect effects of the COVID-19 pandemic. The review presents data sources and different forms of death counts, and discusses empirical findings on direct and indirect effects of the pandemic and interventions on disease burden as well as the distribution of health risks.

Facilitators and barriers of preventive behaviors against COVID-19 during Ramadan: A phenomenology of Indonesian adults

Introduction

Intercity mobility restriction, physical distancing, and mask-wearing are preventive behaviors to reduce the transmission of COVID-19. However, strong cultural and religious traditions become particular challenges in Indonesia. This study uses the Behavior Change Wheel to explore barriers and facilitators for intercity mobility restriction, physical distancing, and mask-wearing during Ramadan.

Methods

Semi-structured in-depth interviews with 50 Indonesian adults were conducted between 10 April and 4 June 2020. Having mapped codes into the Capacity, Opportunity, Motivation - Behavior (COM-B), and Theoretical Domain Framework (TDF) model, we conducted summative content analysis to analyze the most identified factors to preventive behaviors and proposed interventions to address those factors.

Results

Belief about the consequence of preventive behaviors was the most mentioned facilitator to all preventive behaviors among compliers. However, optimism as a TDF factor was commonly mentioned as a barrier to preventive behaviors among non-compliers, while environmental context and resources were the most commonly mentioned factors for intercity mobility restriction.

Conclusions

Public health intervention should be implemented considering the persuasion and involvement of religious and local leaders. Concerning job and economic context, policy related to the intercity mobility restriction should be reconsidered to prevent a counterproductive effect.

Cross-border healthcare: A review and applicability to North America during COVID-19

Cross-border healthcare is an international agreement for the provision of out of country healthcare for citizens of partnered countries. The European Union (EU) has established itself as a world leader in cross-border healthcare. During the Coronavirus disease of 2019 (COVID-19) pandemic, the EU used this system to maximize utilization of resources. Countries with capacity accepted critically ill patients from overwhelmed nations, borders remained open to healthcare workers and those seeking medical care in an effort to share the burden of this pandemic. Significant research into the challenges and successes of cross-border healthcare was completed prior to COVID-19, which demonstrated significant benefit for patients. In North America, the response to the COVID-19 crisis has been more isolationist. The Canada-United States border has been closed and bans placed on healthcare workers crossing the border for work. Prior to COVID-19, cross-border healthcare was rare in North America despite its need. We reviewed the literature surrounding cross-border healthcare in the EU, as well as the need for a similar system in North America. We found the EU cross-border healthcare agreements are generally mutually beneficial for participating countries. The North American literature suggested a cross-border healthcare system is feasible. A number of challenges could be identified based on the EU experience. A prior agreement may have been beneficial during the COVID-19 crisis as many Canadian healthcare institutions-maintained capacity to accept critically ill patients.

Assessing the effectiveness of quarantine measures during the COVID-19 pandemic in Chile using Bayesian structural time series models

Background

With the emergence of the COVID-19 pandemic, all existing health protocols were tested under the worst health crisis humanity has experienced since the Black Death in the 14th century. Countries in Latin America have been the epicenter of the COVID-19 pandemic, with more than 1.5 million people killed. Worldwide health measures have included quarantines, border closures, social distancing, and mask use, among others. In particular, Chile implemented total or partial quarantine measures depending on the number of infections in each region of the country. Therefore, it is necessary to study the effectiveness of these quarantines in relation to the public health measures implemented by government entities at the national level.

Objective

The main objective of this study is to analyze the effectiveness of national- and region-level quarantines in Chile during the pandemic based on information published by the Chilean Ministry of Health, and answers to the following question are sought: Were quarantine measures in Chile effective during the COVID-19 pandemic?

Methods

The causal effect between the rates of COVID-19 infections and the population rates in Phase 1 and Phase 2 quarantines in the period from March 2020 to March 2021 in different regions of Chile were evaluated using intervention analyses obtained through Bayesian structural time series models. In addition, the Kendall correlation coefficient obtained through the copula approach was used to evaluate the comovement between these rates.

Results

In 75% of the Chilean regions under study (12 regions out of a total of 16), an effective Phase 1 quarantine, which was implemented to control and reduce the number of cases of COVID-19 infection, was observed. The main regions that experienced a decrease in cases were those located in the north and center of Chile. Regarding Phase 2, the COVID-19 pandemic was effectively managed in 31% (5 out of 16) of the regions. In the south-central and extreme southern regions of Chile, the effectiveness of these phases was null.

Conclusion

The findings indicate that in the northern and central regions of Chile, the Phase 1 quarantine application period was an effective strategy to prevent an increase in COVID-19 infections. The same observation was made with respect to Phase 2, which was effective in five regions of northern Chile; in the rest of the regions, the effectiveness of these phases was weak or null.

Randomized trials on non-pharmaceutical interventions for COVID-19: a scoping review

OBJECTIVE

We aimed at providing a systematic overview of randomised trials assessing non-pharmaceutical interventions (NPIs) to prevent COVID-19.

DESIGN

Scoping review.

METHODS

We included all randomised trials assessing NPIs to prevent COVID-19 in any country and setting registered in ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform using the COVID-evidence platform (until 17 August 2021). We searched for corresponding publications in MEDLINE/PubMed, Google Scholar, the Living Overview of Evidence platform, and the Cochrane COVID-19 registry as well as for results posted in registries (until 14 November 2021). Descriptive statistics using numbers and percentages were used in the narrative synthesis of the results.

RESULTS

We identified 41 randomised trials. Of them, 12 were completed (29.3%) including 9 with published results. The 41 trials planned to recruit a median of 1700 participants (IQR 588-9500, range 30-35 256 399) with a median planned duration of 8 months (IQR 3-14, range 1-24). Most came from the USA (n=11, 26.8%). The trials mostly assessed protective equipment (n=11, 26.8%), COVID-19-related information and education programmes (n=9, 22.0%), access to mass events under specific safety measures (n=5, 12.2%), testing and screening strategies (n=5, 12.2%) and hygiene management (n=5, 12.2%).

CONCLUSIONS

Worldwide, 41 randomised trials assessing NPIs have been initiated with published results available to inform policy decisions for only 9 of them. A long-term research agenda including behavioural, environmental, social and systems level interventions is urgently needed to guide policies and practices in the current and future public health emergencies.

A Survey of Public Health Failures During COVID-19

The prolonged coronavirus disease 2019 (COVID-19) pandemic has raised concerns about the failures in the public health measures used to manage the spread of this deadly virus. This review focuses its attention on research papers that at their core highlight the individual public health measures instituted by organizations, institutions, and the government of the United States (US) since the start of the COVID-19 pandemic and that were published in 2019 to 2022. Together, these sources help paint a well-rounded view of the US management of this pandemic so that conclusions may be drawn from mistakes that were made and this country may respond better in the future to such situations. This paper is unique because it highlights the areas where improvement is needed, whereas other published work describes the measures taken and how they were carried out, not the failures, which leaves a gap in the literature that this paper hopes to fill. Through a deep dive into public health measures, seven areas in which improvements could be made were pinpointed by the authors. Such measures included mask mandates, social distancing, lockdown/quarantine, hand hygiene, COVID-19 testing, travel screening, and vaccine hesitancy. In exploring each measure, a discussion was carried out about its benefits and shortcomings in alleviating the ramifications of a global pandemic. In addition to the poor supply chain for critical products like personal protective equipment (PPE), the miscommunication between states and federal policies did not allow for the entirety of the US to respond cohesively in the face of the COVID-19 pandemic. This general review is crucial to know what is working and what needs to be changed to increase the benefits provided to the population.

Evolving trend change during the COVID-19 pandemic

Coronavirus disease (COVID-19) has caused unimaginable damage to public health and socio-economic structures worldwide; thus, an epidemiological depiction of the global evolving trends of this disease is necessary. As of March 31, 2022, the number of cases increased gradually over the four waves of the COVID-19 pandemic, indicating the need for continuous countermeasures. The highest total cases per million and total deaths per million were observed in Europe (240,656.542) and South America (2,912.229), despite these developed countries having higher vaccination rates than other continents, such as Africa. In contrast, the lowest of the above two indices were found in undeveloped African countries, which had the lowest number of vaccinations. These data indicate that the COVID-19 pandemic is positively related to the socio-economic development level; meanwhile, the data suggest that the vaccine currently used in these continents cannot completely prevent the spread of COVID-19. Thus, rethinking the feasibility of a single vaccine to control the disease is needed. Although the number of cases in the fourth wave increased exponentially compared to those of the first wave, ~43.1% of deaths were observed during the first wave. This was not only closely linked to multiple factors, including the inadequate preparation for the initial response to the COVID-19 pandemic, the gradual reduction in the severity of additional variants, and the protection conferred by prior infection and/or vaccination, but this also indicated the change in the main driving dynamic in the fourth wave. Moreover, at least 12 variants were observed globally, showing a clear spatiotemporal profile, which provides the best explanation for the presence of the four waves of the pandemic. Furthermore, there was a clear shift in the trend from multiple variants driving the spread of disease in the early stage of the pandemic to a single Omicron lineage predominating in the fourth wave. These data suggest that the Omicron variant has an advantage in transmissibility over other contemporary co-circulating variants, demonstrating that monitoring new variants is key to reducing further spread. We recommend that public health measures, along with vaccination and testing, are continually implemented to stop the COVID-19 pandemic.

Transmission and control of SARS-CoV-2 on ground public transport: A rapid review of the literature up to May 2021

Background

During a pandemic, public transport is strategically important for keeping the country going and getting people where they need to be. The essential nature of public transport puts into focus the risk of transmission of SARS-CoV-2 in this sector; rapid and diverse work has been done to attempt to understand how transmission happens in this context and what factors influence risk.

Objectives

This review aimed to provide a narrative overview of the literature assessing transmission, or potential for transmission, of SARS-CoV-2 on ground-based public transport, as well as studies assessing the effectiveness of control measures on public transport during the early part of the pandemic (up to May 2021).

Methods

An electronic search was conducted using Web of Science, Ovid, the Cochrane Library, ProQuest, Pubmed, and the WHO global COVID database. Searches were run between December 2020 and May 2021.

Results

The search strategy identified 734 papers, of which 28 papers met the inclusion criteria for the review; 10 papers assessed transmission of SARS-CoV-2, 11 assessed control measures, and seven assessed levels of contamination. Eleven papers were based on modelling approaches; 17 studies were original studies reporting empirical COVID-19 data.

Conclusions

The literature is heterogeneous, and there are challenges for measurement of transmission in this setting. There is evidence for transmission in certain cases, and mixed evidence for the presence of viral RNA in transport settings; there is also evidence for some reduction of risk through mitigation. However, the routes of transmission and key factors contributing to transmission of SARS-CoV-2 on public transport were not clear during the early stage of the pandemic. Gaps in understanding are discussed and six key questions for future research have been posed. Further exploration of transmission factors and effectiveness of mitigation strategies is required in order to support decision making.

Prevalence and Dynamics of SARS-CoV-2 Antibodies in the Population of St. Petersburg, Russia

Background

The aim of the study was to assess the prevalence of seropositive status for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-IgA, -IgM, and -IgG; its dynamics in connection with restrictive measures during the coronavirus disease (COVID-19) pandemic; and the quantitative dynamics of antibody levels in the population of St. Petersburg, Russia.

Methods

From May to November 2020, a retrospective analysis of Saint Petersburg State University Hospital laboratory database was performed. The database included 158,283 test results of 87,067 patients for SARS-CoV-2 detection by polymerase chain reaction (PCR) and antibody detection of SARS-CoV-2-IgA, -IgM, and -IgG. The dynamics of antibody level was assessed using R v.3.6.3.

Results

The introduction of a universal lockdown was effective in containing the spread of COVID-19. The proportion of seropositive patients gradually decreased; approximately 50% of these patients remained seropositive for IgM after 3–4 weeks; for IgG, by follow-up week 22; and for IgA, by week 12. The maximum decrease in IgG and IgA was observed 3–4 months and 2 months after the detection of the seropositive status, respectively.

Conclusions

The epidemiological study of post-infection immunity to COVID-19 demonstrates significant differences in the dynamics of IgA, IgM, and IgG seropositivity and in PCR test results over time, which is linked to the introduction of restrictive measures. Both the proportion of seropositive patients and the level of all antibodies decreased in terms of the dynamics, and only approximately half of these patients remained IgG-positive 6 months post-infection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44197-022-00041-9.

Optimal use of COVID-19 Ag-RDT screening at border crossings to prevent community transmission: A modeling analysis

Countries around the world have implemented restrictions on mobility, especially cross-border travel to reduce or prevent SARS-CoV-2 community transmission. Rapid antigen testing (Ag-RDT), with on-site administration and rapid turnaround time may provide a valuable screening measure to ease cross-border travel while minimizing risk of local transmission. To maximize impact, we developed an optimal Ag-RDT screening algorithm for cross-border entry. Using a previously developed mathematical model, we determined the daily number of imported COVID-19 cases that would generate no more than a relative 1% increase in cases over one month for different effective reproductive numbers (Rt) and COVID-19 prevalence within the recipient country. We then developed an algorithm-for differing levels of Rt, arrivals per day, mode of travel, and SARS-CoV-2 prevalence amongst travelers-to determine the minimum proportion of people that would need Ag-RDT testing at border crossings to ensure no greater than the relative 1% community spread increase. When daily international arrivals and/or COVID-19 prevalence amongst arrivals increases, the proportion of arrivals required to test using Ag-RDT increases. At very high numbers of international arrivals/COVID-19 prevalence, Ag-RDT testing is not sufficient to prevent increased community spread, especially when recipient country prevalence and Rt are low. In these cases, Ag-RDT screening would need to be supplemented with other measures to prevent an increase in community transmission. An efficient Ag-RDT algorithm for SARS-CoV-2 testing depends strongly on the epidemic status within the recipient country, volume of travel, proportion of land and air arrivals, test sensitivity, and COVID-19 prevalence among travelers.

Children and Adolescents' Behavioral Patterns in Response to Escalating COVID-19 Restriction Reveal Sex and Age Differences

PURPOSE

The COVID-19 pandemic affects students in a myriad of different ways. Our prospective, longitudinal study in a cohort of students in Hannover, Germany explores behavioral patterns during escalating COVID-19 restrictions.

METHODS

In total, 777 students between the age of 9 and 20 were assessed for their activity engagement, travel patterns, and self-assessed compliance with protective recommendations at six time points between June 2020 and June 2021 (3,564 observations) and were monitored for severe acute respiratory syndrome coronavirus 2 infection by nasal swab polymerase chain reaction and serum antibody titers.

RESULTS

Activity engagement decreased, but self-assessed compliance with measures such as mask wearing and social distancing was stable during escalating restrictions. Although we found no sex difference during the summer break, when incidence was lowest, females engaged in a higher variety of activities than males for all other time points. Older students engaged in more activities and self-assigned themselves lower compliance values than younger ones. Greater involvement in different activities was seen in households which traveled more frequently. Infection rate in our cohort was low (0.03% acute infections, 1.94% positive seroprevalence).

DISCUSSION

Our study supports the view that, overall, students show high compliance with COVID-19 recommendations and restrictions. The identification of subsets, such as female and older students, with higher risk behavioral patterns should be considered when implementing public information campaigns. In light of the low infection rate in our cohort, we conclude that in-person learning can occur safely if extensive protective measures are in place and the incidence in the general population remains moderate.

Estimating the effect of non-pharmaceutical interventions to mitigate COVID-19 spread in Saudi Arabia

BACKGROUND

The Kingdom of Saudi Arabia (KSA) quickly controlled the spread of SARS-CoV-2 by implementing several non-pharmaceutical interventions (NPIs), including suspension of international and national travel, local curfews, closing public spaces (i.e., schools and universities, malls and shops), and limiting religious gatherings. The KSA also mandated all citizens to respect physical distancing and to wear face masks. However, after relaxing some restrictions during June 2020, the KSA is now planning a strategy that could allow resuming in-person education and international travel. The aim of our study was to evaluate the effect of NPIs on the spread of the COVID-19 and test strategies to open schools and resume international travel.

METHODS

We built a spatial-explicit individual-based model to represent the whole KSA population (IBM-KSA). The IBM-KSA was parameterized using country demographic, remote sensing, and epidemiological data. A social network was created to represent contact heterogeneity and interaction among age groups of the population. The IBM-KSA also simulated the movement of people across the country based on a gravity model. We used the IBM-KSA to evaluate the effect of different NPIs adopted by the KSA (physical distancing, mask-wearing, and contact tracing) and to forecast the impact of strategies to open schools and resume international travels.

RESULTS

The IBM-KSA results scenarios showed the high effectiveness of mask-wearing, physical distancing, and contact tracing in controlling the spread of the disease. Without NPIs, the KSA could have reported 4,824,065 (95% CI: 3,673,775-6,335,423) cases by June 2021. The IBM-KSA showed that mandatory mask-wearing and physical distancing saved 39,452 lives (95% CI: 26,641-44,494). In-person education without personal protection during teaching would have resulted in a high surge of COVID-19 cases. Compared to scenarios with no personal protection, enforcing mask-wearing and physical distancing in schools reduced cases, hospitalizations, and deaths by 25% and 50%, when adherence to these NPIs was set to 50% and 70%, respectively. The IBM-KSA also showed that a quarantine imposed on international travelers reduced the probability of outbreaks in the country.

CONCLUSIONS

This study showed that the interventions adopted by the KSA were able to control the spread of SARS-CoV-2 in the absence of a vaccine. In-person education should be resumed only if NPIs could be applied in schools and universities. International travel can be resumed but with strict quarantine rules. The KSA needs to keep strict NPIs in place until a high fraction of the population is vaccinated in order to reduce hospitalizations and deaths.

Effectiveness of International Travel Controls for Delaying Local Outbreaks of COVID-19

During the coronavirus disease pandemic, international travel controls have been widely adopted. To determine the effectiveness of these measures, we analyzed data from 165 countries and found that early implementation of international travel controls led to a mean delay of 5 weeks in the first epidemic peak of cases.

International travel in times of the COVID-19 pandemic: The case of German school breaks

The COVID-19 pandemic has triggered severe global restrictions on international travel with the intention of limiting the spread of SARS-CoV-2 across countries. This paper studies the causal effect of the partial relaxation of these travel restrictions in Europe on the COVID-19 incidence in Germany during the summer months of 2020. It exploits the staggered start of the summer school breaks across German states as an exogenous shock to the travel opportunities of the population. While the school breaks also increased mobility within Germany, the event-study type regressions precisely control for domestic mobility and local COVID-19-related restrictions. The intention-to-treat effects of the relaxed travel restrictions show a significant and sizable increase of the COVID-19 incidence in German counties during the later weeks of the school breaks. Part of the increase can be attributed to a mandatory testing regime for travel returnees from high-incidence areas.

The Organic Turn: Coping With Pandemic and Non-pandemic Challenges by Integrating Evidence-, Theory-, Experience-, and Context-Based Knowledge in Advising Health Policy

The COVID-19 pandemic has posed an extraordinary challenge for public health and health policy. Questions have arisen concerning the main strategies to cope with this situation and the lessons to be learned from the pandemic. This conceptual paper aims to clarify these questions via sociological concepts. Regarding coping strategies used during the pandemic, there is a strong tendency for health policymakers to rely on expert knowledge rather than on evidence-based knowledge. This has caused the evidence-based healthcare community to respond to urgent demands for advice by rapidly processing new knowledge. Nonetheless, health policymakers still mainly rely on experts in making policy decisions. Our sociological analysis of this situation identified three lessons for coping with pandemic and non-pandemic health challenges: (1) the phenomenon of accelerating knowledge processing could be interpreted from the organizational innovation perspective as a shift from traditional mechanistic knowledge processing to more organic forms of knowledge processing. This can be described as an "organic turn." (2) The return of experts is part of this organic turn and shows that experts provide both evidence-based knowledge as well as theoretical, experiential, and contextual knowledge. (3) Experts can use theory to expeditiously provide advice at times when there is limited evidence available and to provide complexity-reducing orientation for decisionmakers at times where knowledge production leads to an overload of knowledge; thus, evidence-based knowledge should be complemented by theory-based knowledge in a structured two-way interaction to obtain the most comprehensive and valid recommendations for health policy.

Effectiveness of public health measures in reducing the incidence of covid-19, SARS-CoV-2 transmission, and covid-19 mortality: systematic review and meta-analysis

OBJECTIVE

To review the evidence on the effectiveness of public health measures in reducing the incidence of covid-19, SARS-CoV-2 transmission, and covid-19 mortality.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, CINAHL, Biosis, Joanna Briggs, Global Health, and World Health Organization COVID-19 database (preprints).

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Observational and interventional studies that assessed the effectiveness of public health measures in reducing the incidence of covid-19, SARS-CoV-2 transmission, and covid-19 mortality.

MAIN OUTCOME MEASURES

The main outcome measure was incidence of covid-19. Secondary outcomes included SARS-CoV-2 transmission and covid-19 mortality.

DATA SYNTHESIS

DerSimonian Laird random effects meta-analysis was performed to investigate the effect of mask wearing, handwashing, and physical distancing measures on incidence of covid-19. Pooled effect estimates with corresponding 95% confidence intervals were computed, and heterogeneity among studies was assessed using Cochran's Q test and the I2 metrics, with two tailed P values.

RESULTS

72 studies met the inclusion criteria, of which 35 evaluated individual public health measures and 37 assessed multiple public health measures as a "package of interventions." Eight of 35 studies were included in the meta-analysis, which indicated a reduction in incidence of covid-19 associated with handwashing (relative risk 0.47, 95% confidence interval 0.19 to 1.12, I2=12%), mask wearing (0.47, 0.29 to 0.75, I2=84%), and physical distancing (0.75, 0.59 to 0.95, I2=87%). Owing to heterogeneity of the studies, meta-analysis was not possible for the outcomes of quarantine and isolation, universal lockdowns, and closures of borders, schools, and workplaces. The effects of these interventions were synthesised descriptively.

CONCLUSIONS

This systematic review and meta-analysis suggests that several personal protective and social measures, including handwashing, mask wearing, and physical distancing are associated with reductions in the incidence covid-19. Public health efforts to implement public health measures should consider community health and sociocultural needs, and future research is needed to better understand the effectiveness of public health measures in the context of covid-19 vaccination.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020178692.

Role of urban planning characteristics in forming pandemic resilient cities - Case study of Covid-19 impacts on European cities within England, Germany and Italy

In recent decades, the world has witnessed a variety of emerging infectious diseases, some of which developed to pandemic world threatening outbreaks, the ongoing COVID-19 is known to be taking the lead in claiming lives around the globe and thus, urging people to trail its increasing figures. Therefore, this research aims to emphasize the role of urban planning in containing such outbreaks through running a series of analytical and statistical studies on European cities, worst inflicted region, to analyze the main urban features they share and that may be propagating the disease spread according to their population size, density, form, intracity connectivity and intercity connectivity. This study, as far as we know of, is the first practice to evaluate both the individual and combined impacts of these factors on recorded rates of infections. According to the context of this research, it is concluded that the diversity found in urban features are, to a large degree, related to cities being more vulnerable than others. Intracity connectivity through public transport is found to be the possible prime factor of this study, and is followed by population size, density, and intercity connectivity. Urban morphology seems to also contribute to such outbreak, with both radial and grid cities being associated to higher infections rates as to linear cities. Henceforth, setting priorities in post-pandemic urban planning schemes is essential for planning resilient cities that are capable to thrive and maintain functionality with lowest possible infections amid else possible diseases that are to follow in severity.

COVID-19 border closures cause humanitarian crew change crisis at sea

The COVID-19 pandemic has caused many countries to close their borders to travellers, in an attempt to contain the spread of the virus. Given the initially indiscriminate travel restrictions adopted in March 2020, many seafarers have been stranded on their ships, well beyond their initial labour contracts. Notwithstanding repeated calls by the United Nations, the shipping industry, and maritime unions to designate seafarers as "key workers" in all jurisdictions, many countries still do not allow crew change. While crew change is however generally possible in many ports, the number of people stranded at sea remains unacceptably high, which signals wide-spread breaches of the United Nations 2006 Maritime Labour Convention (MLC, 2006). This humanitarian crisis needs to be resolved soon, as its continuation risks eroding the hard-won Maritime Labour Convention.

COVID-19 pandemic: health impact of staying at home, social distancing and 'lockdown' measures-a systematic review of systematic reviews

BACKGROUND

To systematically review the evidence published in systematic reviews (SR) on the health impact of staying at home, social distancing and lockdown measures. We followed a systematic review approach, in line with PRISMA guidelines.

METHODS

In October 2020, we searched the databases Cochrane Database of Systematic Reviews, Ovid Medline, Ovid Embase and Web of Science, using a pre-defined search strategy.

RESULTS

The literature search yielded an initial list of 2172 records. After screening of titles and abstracts, followed by full-text screening, 51 articles were retained and included in the analysis. All of them referred to the first wave of the coronavirus disease 2019 pandemic. The direct health impact that was covered in the greatest number (25) of SR related to mental health, followed by 13 SR on healthcare delivery and 12 on infection control. The predominant areas of indirect health impacts covered by the included studies relate to the economic and social impacts. Only three articles mentioned the negative impact on education.

CONCLUSIONS

The focus of SR so far has been uneven, with mental health receiving the most attention. The impact of measures to contain the spread of the virus can be direct and indirect, having both intended and unintended consequences.

HIGHLIGHTS

Institutional and behaviour-change interventions to support COVID-19 public health measures: a review by the Lancet Commission Task Force on public health measures to suppress the pandemic

The Lancet COVID-19 Commission Task Force for Public Health Measures to Suppress the Pandemic was launched to identify critical points for consideration by governments on public health interventions to control coronavirus disease 2019 (COVID-19). Drawing on our review of published studies of data analytics and modelling, evidence synthesis and contextualisation, and behavioural science evidence and theory on public health interventions from a range of sources, we outline evidence for a range of institutional measures and behaviour-change measures. We cite examples of measures adopted by a range of countries, but especially jurisdictions that have, thus far, achieved low numbers of COVID-19 deaths and limited community transmission of severe acute respiratory syndrome coronavirus 2. Finally, we highlight gaps in knowledge where research should be undertaken. As countries consider long-term measures, there is an opportunity to learn, improve the response and prepare for future pandemics.

Rapid COVID-19 Antigen Testing in Croatia: Risk Perception Plays an Important Role in the Epidemic Control

Aim: To explore the clinical presentation and epidemiological history of the subjects who underwent SARS-CoV-2 antigen testing. Methods: We included 1,000 consecutive subjects who presented themselves at the diagnostic clinic in Croatia and analyzed their symptoms and epidemiological history. All subjects were classified into three groups, according to their reason of arrival; symptomatic, contacts of confirmed patients, and those who were tested due to administrative reasons. Results: On average, there were 24% of positive antigen results; the positivity rate was 51% among symptomatic, 16% in contacts, and 5% of administrative patients. The commonest symptoms of the disease included febrility and anosmia. We developed a clinical score to predict SARS-CoV-2 positivity, which had an area under the curve of 79.3 [95% confidence intervals (CI) 75.8-82.8]. Contact with the isolated person [odds ratio 0.54 (95% CI 0.31-0.94)] and international travel had a protective effect [0.20 (0.09-0.43)], suggesting that risk perception and mandatory pretravel measures had a key role in the determination of the infection risk. Conclusions: A combination of clinical symptoms can have reasonable predictive power for an antigen-positive test result. Risk perception seems to have a role in the epidemic spread, probably via stricter adherence to personal preventative measures.

COVID-19 international border surveillance at Toronto's Pearson Airport: a cohort study

OBJECTIVES

The primary objective was to estimate the positivity rate of air travellers coming to Toronto, Canada in September and October 2020, on arrival and on day 7 and day 14. The secondary objectives were to estimate the degree of risk based on country of origin and to assess knowledge and attitudes towards COVID-19 control measures and subjective well-being during the quarantine period.

DESIGN

Prospective cohort of arriving international travellers.

SETTING

Toronto Pearson Airport Terminal 1, Toronto, Canada.

PARTICIPANTS

Participants of this study were passengers arriving on international flights. Inclusion criteria were those aged 18 or older who had a final destination within 100 km of the airport, spoke English or French, and provided consent. Excluded were those taking a connecting flight, had no internet access, exhibited symptoms of COVID-19 on arrival or were exempted from quarantine.

MAIN OUTCOME MEASURES

Positive for SARS-CoV-2 virus on reverse transcription PCR with self-administered oral-nasal swab and general well-being using the WHO-5 Well-being Index.

RESULTS

Of 16 361 passengers enrolled, 248 (1.5%, 95% CI 1.3% to 1.7%) tested positive. Of these, 167 (67%) were identified on arrival, 67 (27%) on day 7, and 14 (6%) on day 14. The positivity rate increased from 1% in September to 2% in October. Average well-being score declined from 19.8 (out of a maximum of 25) to 15.5 between arrival and day 7 (p<0.001).

CONCLUSIONS

A single arrival test will pick up two-thirds of individuals who will become positive by day 14, with most of the rest detected on the second test on day 7. These results support strategies identified through mathematical models that a reduced quarantine combined with testing can be as effective as a 14-day quarantine.

Pervasive systemic drivers underpin COVID-19 vulnerabilities in migrants

Asylum seekers, refugees and undocumented foreign nationals have always been identified as a vulnerable population owing to the longstanding structural barriers and inequalities that they continually face. Their vulnerabilities have become more conspicuous and exacerbated since the advent of the Coronavirus disease of 2019 (COVID-19) pandemic. The plights of these migrants around the world, in the COVID-19 era, are therefore underpinned by not-so-new but enforced, re-emerging and adapting pre-existing systemic inequality drivers. Long-standing and pre-existing systemic drivers such as nationalism and anti-migrant or xenophobic stigma, in the context of the COVID-19 pandemic, have metamorphosed into COVID-19 nationalism and COVID-19-related xenophobic stigma respectively, fomenting discriminatory and segregation-laden policies and programmes. Transformative changes of asylum policies taking holistic and systematic perspectives while fostering the involvement of migrants in government planning and policy processes to redesign better policies are required to tackle the pervasive systemic drivers that underpin COVID-19 vulnerabilities in the identified migrant groups.

Managing borders during public health emergencies of international concern: a proposed typology of cross-border health measures

BACKGROUND

The near universal adoption of cross-border health measures during the COVID-19 pandemic worldwide has prompted significant debate about their effectiveness and compliance with international law. The number of measures used, and the range of measures applied, have far exceeded previous public health emergencies of international concern. However, efforts to advance research, policy and practice to support their effective use has been hindered by a lack of clear and consistent definition.

RESULTS

Based on a review of existing datasets for cross-border health measures, such as the Oxford Coronavirus Government Response Tracker and World Health Organization Public Health and Social Measures, along with analysis of secondary and grey literature, we propose six categories to define measures more clearly and consistently - policy goal, type of movement (travel and trade), adopted by public or private sector, level of jurisdiction applied, stage of journey, and degree of restrictiveness. These categories are then brought together into a proposed typology that can support research with generalizable findings and comparative analyses across jurisdictions. Addressing the current gaps in evidence about travel measures, including how different jurisdictions apply such measures with varying effects, in turn, enhances the potential for evidence-informed decision-making based on fuller understanding of policy trade-offs and externalities. Finally, through the adoption of standardized terminology and creation of an agreed evidentiary base recognized across jurisdictions, the typology can support efforts to strengthen coordinated global responses to outbreaks and inform future efforts to revise the WHO International Health Regulations (2005).

CONCLUSIONS

The widespread use of cross-border health measures during the COVID-19 pandemic has prompted significant reflection on available evidence, previous practice and existing legal frameworks. The typology put forth in this paper aims to provide a starting point for strengthening research, policy and practice.

Canada's response to international travel during COVID-19 pandemic - a media analysis

Background

The media play a critical role in informing the public about the COVID-19 pandemic. Throughout the pandemic, international travel has been a highly contested subject at both the international and national levels. We examined Canadian media reporting on international travel restrictions during the pandemic, how these restrictions aligned with the International Health Regulations (IHR 2005), and how the narrative around international travel evolved over time.

Methods

We analysed articles from Canada’s top three national newspapers by circulation – The Globe and Mail, The National Post and The Toronto Star - published between Jan 1, 2020 - May 31, 2020. Our search yielded a total of 378 articles across the three newspapers. After removing duplicates and screening the remaining articles, we included a total of 62 articles for the analysis. We conducted a qualitative media content analysis by using an inductive coding approach.

Results

Three major themes were identified within the articles. These included: 1) The role of scientific and expert evidence in implementing travel restrictions; 2) Federal legislation, regulation and enforcement of international travel measures; and 3) Compliance with World Health Organization (WHO) guidelines in travel restriction policy- and decision-making. The federal government relied primarily on scientific evidence for implementing international travel restrictions and fully exercised its powers under the Quarantine Act to enforce travel regulations and comply with the IHR 2005. The government embraced a rules-based international order by following WHO recommendations on international travel, contributing to a delay in border closure and travel restrictions until mid-March.

Conclusion

The media focussed significantly on international travel-related issues during the early phase of the pandemic. The dominant media narrative surrounded the need for earlier travel restrictions against international travel.

Estimating the impact of control measures to prevent outbreaks of COVID-19 associated with air travel into a COVID-19-free country

We aimed to estimate the risk of COVID-19 outbreaks associated with air travel to a COVID-19-free country [New Zealand (NZ)]. A stochastic version of the SEIR model CovidSIM v1.1, designed specifically for COVID-19 was utilised. We first considered historical data for Australia before it eliminated COVID-19 (equivalent to an outbreak generating 74 new cases/day) and one flight per day to NZ with no interventions in place. This gave a median time to an outbreak of 0.2 years (95% range of simulation results: 3 days to 1.1 years) or a mean of 110 flights per outbreak. However, the combined use of a pre-flight PCR test of saliva, three subsequent PCR tests (on days 1, 3 and 12 in NZ), and various other interventions (mask use and contact tracing) reduced this risk to one outbreak after a median of 1.5 years (20 days to 8.1 years). A pre-flight test plus 14 days quarantine was an even more effective strategy (4.9 years; 2,594 flights). For a much lower prevalence (representing only two new community cases per week in the whole of Australia), the annual risk of an outbreak with no interventions was 1.2% and had a median time to an outbreak of 56 years. In contrast the risks associated with travellers from Japan and the United States was very much higher and would need quarantine or other restrictions. Collectively, these results suggest that multi-layered interventions can markedly reduce the risk of importing the pandemic virus via air travel into a COVID-19-free nation. For some low-risk source countries, there is the potential to replace 14-day quarantine with alternative interventions. However, all approaches require public and policy deliberation about acceptable risks, and continuous careful management and evaluation.

Reducing travel-related SARS-CoV-2 transmission with layered mitigation measures: symptom monitoring, quarantine, and testing

BACKGROUND

Balancing the control of SARS-CoV-2 transmission with the resumption of travel is a global priority. Current recommendations include mitigation measures before, during, and after travel. Pre- and post-travel strategies including symptom monitoring, antigen or nucleic acid amplification testing, and quarantine can be combined in multiple ways considering different trade-offs in feasibility, adherence, effectiveness, cost, and adverse consequences.

METHODS

We used a mathematical model to analyze the expected effectiveness of symptom monitoring, testing, and quarantine under different estimates of the infectious period, test-positivity relative to time of infection, and test sensitivity to reduce the risk of transmission from infected travelers during and after travel.

RESULTS

If infection occurs 0-7 days prior to travel, immediate isolation following symptom onset prior to or during travel reduces risk of transmission while traveling by 30-35%. Pre-departure testing can further reduce risk, with testing closer to the time of travel being optimal even if test sensitivity is lower than an earlier test. For example, testing on the day of departure can reduce risk while traveling by 44-72%. For transmission risk after travel with infection time up to 7 days prior to arrival at the destination, isolation based on symptom monitoring reduced introduction risk at the destination by 42-56%. A 14-day quarantine after arrival, without symptom monitoring or testing, can reduce post-travel risk by 96-100% on its own. However, a shorter quarantine of 7 days combined with symptom monitoring and a test on day 5-6 after arrival is also effective (97--100%) at reducing introduction risk and is less burdensome, which may improve adherence.

CONCLUSIONS

Quarantine is an effective measure to reduce SARS-CoV-2 transmission risk from travelers and can be enhanced by the addition of symptom monitoring and testing. Optimal test timing depends on the effectiveness of quarantine: with low adherence or no quarantine, optimal test timing is close to the time of arrival; with effective quarantine, testing a few days later optimizes sensitivity to detect those infected immediately before or while traveling. These measures can complement recommendations such as social distancing, using masks, and hand hygiene, to further reduce risk during and after travel.

International travel-related control measures to contain the COVID-19 pandemic: a rapid review

BACKGROUND

In late 2019, the first cases of coronavirus disease 2019 (COVID-19) were reported in Wuhan, China, followed by a worldwide spread. Numerous countries have implemented control measures related to international travel, including border closures, travel restrictions, screening at borders, and quarantine of travellers.

OBJECTIVES

To assess the effectiveness of international travel-related control measures during the COVID-19 pandemic on infectious disease transmission and screening-related outcomes.

SEARCH METHODS

We searched MEDLINE, Embase and COVID-19-specific databases, including the Cochrane COVID-19 Study Register and the WHO Global Database on COVID-19 Research to 13 November 2020.

SELECTION CRITERIA

We considered experimental, quasi-experimental, observational and modelling studies assessing the effects of travel-related control measures affecting human travel across international borders during the COVID-19 pandemic. In the original review, we also considered evidence on severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). In this version we decided to focus on COVID-19 evidence only. Primary outcome categories were (i) cases avoided, (ii) cases detected, and (iii) a shift in epidemic development. Secondary outcomes were other infectious disease transmission outcomes, healthcare utilisation, resource requirements and adverse effects if identified in studies assessing at least one primary outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts and subsequently full texts. For studies included in the analysis, one review author extracted data and appraised the study. At least one additional review author checked for correctness of data. To assess the risk of bias and quality of included studies, we used the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool for observational studies concerned with screening, and a bespoke tool for modelling studies. We synthesised findings narratively. One review author assessed the certainty of evidence with GRADE, and several review authors discussed these GRADE judgements.

MAIN RESULTS

Overall, we included 62 unique studies in the analysis; 49 were modelling studies and 13 were observational studies. Studies covered a variety of settings and levels of community transmission. Most studies compared travel-related control measures against a counterfactual scenario in which the measure was not implemented. However, some modelling studies described additional comparator scenarios, such as different levels of stringency of the measures (including relaxation of restrictions), or a combination of measures. Concerns with the quality of modelling studies related to potentially inappropriate assumptions about the structure and input parameters, and an inadequate assessment of model uncertainty. Concerns with risk of bias in observational studies related to the selection of travellers and the reference test, and unclear reporting of certain methodological aspects. Below we outline the results for each intervention category by illustrating the findings from selected outcomes. Travel restrictions reducing or stopping cross-border travel (31 modelling studies) The studies assessed cases avoided and shift in epidemic development. We found very low-certainty evidence for a reduction in COVID-19 cases in the community (13 studies) and cases exported or imported (9 studies). Most studies reported positive effects, with effect sizes varying widely; only a few studies showed no effect. There was very low-certainty evidence that cross-border travel controls can slow the spread of COVID-19. Most studies predicted positive effects, however, results from individual studies varied from a delay of less than one day to a delay of 85 days; very few studies predicted no effect of the measure. Screening at borders (13 modelling studies; 13 observational studies) Screening measures covered symptom/exposure-based screening or test-based screening (commonly specifying polymerase chain reaction (PCR) testing), or both, before departure or upon or within a few days of arrival. Studies assessed cases avoided, shift in epidemic development and cases detected. Studies generally predicted or observed some benefit from screening at borders, however these varied widely. For symptom/exposure-based screening, one modelling study reported that global implementation of screening measures would reduce the number of cases exported per day from another country by 82% (95% confidence interval (CI) 72% to 95%) (moderate-certainty evidence). Four modelling studies predicted delays in epidemic development, although there was wide variation in the results between the studies (very low-certainty evidence). Four modelling studies predicted that the proportion of cases detected would range from 1% to 53% (very low-certainty evidence). Nine observational studies observed the detected proportion to range from 0% to 100% (very low-certainty evidence), although all but one study observed this proportion to be less than 54%. For test-based screening, one modelling study provided very low-certainty evidence for the number of cases avoided. It reported that testing travellers reduced imported or exported cases as well as secondary cases. Five observational studies observed that the proportion of cases detected varied from 58% to 90% (very low-certainty evidence). Quarantine (12 modelling studies) The studies assessed cases avoided, shift in epidemic development and cases detected. All studies suggested some benefit of quarantine, however the magnitude of the effect ranged from small to large across the different outcomes (very low- to low-certainty evidence). Three modelling studies predicted that the reduction in the number of cases in the community ranged from 450 to over 64,000 fewer cases (very low-certainty evidence). The variation in effect was possibly related to the duration of quarantine and compliance. Quarantine and screening at borders (7 modelling studies; 4 observational studies) The studies assessed shift in epidemic development and cases detected. Most studies predicted positive effects for the combined measures with varying magnitudes (very low- to low-certainty evidence). Four observational studies observed that the proportion of cases detected for quarantine and screening at borders ranged from 68% to 92% (low-certainty evidence). The variation may depend on how the measures were combined, including the length of the quarantine period and days when the test was conducted in quarantine.

AUTHORS' CONCLUSIONS

With much of the evidence derived from modelling studies, notably for travel restrictions reducing or stopping cross-border travel and quarantine of travellers, there is a lack of 'real-world' evidence. The certainty of the evidence for most travel-related control measures and outcomes is very low and the true effects are likely to be substantially different from those reported here. Broadly, travel restrictions may limit the spread of disease across national borders. Symptom/exposure-based screening measures at borders on their own are likely not effective; PCR testing at borders as a screening measure likely detects more cases than symptom/exposure-based screening at borders, although if performed only upon arrival this will likely also miss a meaningful proportion of cases. Quarantine, based on a sufficiently long quarantine period and high compliance is likely to largely avoid further transmission from travellers. Combining quarantine with PCR testing at borders will likely improve effectiveness. Many studies suggest that effects depend on factors, such as levels of community transmission, travel volumes and duration, other public health measures in place, and the exact specification and timing of the measure. Future research should be better reported, employ a range of designs beyond modelling and assess potential benefits and harms of the travel-related control measures from a societal perspective.

COVID-19 Is Not the Flu: Four Graphs From Four Countries

Background: COVID-19 has caused a global public health emergency. Government mitigation strategies included a series of behavior-based prevention policies that had a likely impact on the spread of other contagious respiratory illnesses, such as seasonal influenza. Our aim was to explore how 2019-2020 influenza tracked onto COVID-19 pandemic and its mitigation methods. Materials and Methods: We linked the WHO FluNet database and COVID-19 confirmed cases (Johns Hopkins University) for four countries across the northern (Canada, the United States) and southern hemispheres (Australia, Brazil) for the period 2016-2020. Graphical presentations of longitudinal data were provided. Results: There was a notable reduction in influenza cases for the 2019-2020 season. Northern hemisphere countries experienced a quicker ending to the 2019-2020 seasonal influenza cases (shortened by 4-7 weeks) and virtually no 2020 fall influenza season. Countries from the southern hemisphere experienced drastically low levels of seasonal influenza, with consistent trends that were approaching zero cases after the introduction of COVID-19 measures. Conclusions: It is likely that the COVID-19 mitigation measures played a notable role in the marked decrease in influenza, with little to no influenza activity in both the northern and southern hemispheres. In spite of this reduction in influenza cases, there was still community spread of COVID-19, highlighting the contagiousness of SARS-CoV-2 compared to influenza. These results, together with the higher mortality rate from SARS-CoV-2 compared to influenza, highlight that COVID-19 is a far greater health threat than influenza.

Evidence of the effectiveness of travel-related measures during the early phase of the COVID-19 pandemic: a rapid systematic review

OBJECTIVE

To review the effectiveness of travel measures implemented during the early stages of the COVID-19 pandemic to inform changes on how evidence is incorporated in the International Health Regulations (2005) (IHR).

DESIGN

We used an abbreviated Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols to identify studies that investigated the effectiveness of travel-related measures preprinted or published by 1 June 2020.

RESULTS

We identified 29 studies, of which 26 were modelled. Thirteen studies investigated international measures, while 17 investigated domestic measures (one investigated both). There was a high level of agreement that the adoption of travel measures led to important changes in the dynamics of the early phases of the COVID-19 pandemic: the Wuhan measures reduced the number of cases exported internationally by 70%-80% and led to important reductions in transmission within Mainland China. Additional travel measures, including flight restrictions to and from China, may have led to additional reductions in the number of exported cases. Few studies investigated the effectiveness of measures implemented in other contexts. Early implementation was identified as a determinant of effectiveness. Most studies of international travel measures did not account for domestic travel measures thus likely leading to biased estimates.

CONCLUSION

Travel measures played an important role in shaping the early transmission dynamics of the COVID-19 pandemic. There is an urgent need to address important evidence gaps and also a need to review how evidence is incorporated in the IHR in the early phases of a novel infectious disease outbreak.