key: cord-0858588-7kgx0jtw
authors: Bou-Karroum, Lama; Khabsa, Joanne; Jabbour, Mathilda; Hilal, Nadeen; Haidar, Zeinab; Abi Khalil, Pamela; Khalek, Rima Abdul; Assaf, Jana; Honein-AbouHaidar, Gladys; Samra, Clara Abou; Hneiny, Layal; Al-Awlaqi, Sameh; Hanefeld, Johanna; El-Jardali, Fadi; Akl, Elie A.; Bcheraoui, Charbel El
title: Public Health Effects of Travel-Related Policies on the COVID-19 Pandemic: A Mixed-Methods Systematic Review
date: 2021-07-24
journal: J Infect
DOI: 10.1016/j.jinf.2021.07.017
sha: 72955e2dc3f83a93afdd83778a558d9bf418ad41
doc_id: 858588
cord_uid: 7kgx0jtw

OBJECTIVES: To map travel policies implemented due to COVID-19 during 2020, and conduct a mixed-methods systematic review of health effects of such policies, and related contextual factors. DESIGN: Policy mapping and systematic review DATA SOURCES AND ELIGIBILITY CRITERIA: for the policy mapping, we searched websites of relevant government bodies and used data from the Oxford COVID-19 Government Response Tracker for a convenient sample of 31 countries across different regions. For the systematic review, we searched Medline (Ovid), PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and COVID-19 specific databases. We included randomized controlled trial, non-randomized studies, modeling studies, and qualitative studies. Two independent reviewers selected studies, abstracted data and assessed risk of bias. RESULTS: Most countries adopted a total border closure at the start of the pandemic. For the remainder of the year, partial border closure banning arrivals from some countries or regions was the most widely adopted measure, followed by mandatory quarantine and screening of travelers. The systematic search identified 69 eligible studies, including 50 modeling studies. Both observational and modeling evidence suggest that border closure may reduce the number of COVID-19 cases, disease spread across countries and between regions, and slow the progression of the outbreak. These effects are likely to be enhanced when implemented early, and when combined with measures reducing transmission rates in the community. Quarantine of travelers may decrease the number of COVID-19 cases but its effectiveness depends on compliance and enforcement and is more effective if followed by testing, especially when less than 14 day-quarantine is considered. Screening at departure and/or arrival is unlikely to detect a large proportion of cases or to delay an outbreak. Effectiveness of screening may be improved with increased sensitivity of screening tests, awareness of travelers, asymptomatic screening, and exit screening at country source. While four studies on contextual evidence found that the majority of the public is supportive of travel restrictions, they uncovered concerns about the unintended harms of those policies. CONCLUSION: Most countries adopted full or partial border closure in response to COVID-19 in 2020. Evidence suggests positive effects on controlling the COVID-19 pandemic for border closure (particularly when implemented early), as well as quarantine of travelers (particularly with higher levels of compliance). While these positive effects are enhanced when implemented in combination with other public health measures, they are associated with concerns by the public regarding some unintended effects.

In December 2019, a cluster of pneumonia cases was reported in Wuhan, China 1 , marking the beginning of the COVID-19 outbreak. On 11 March 2020, the World Health Organization (WHO) declared the COVID-19 outbreak as a pandemic. As of March 10, 2021, the pandemic had resulted in more than 117 million cases of COVID-19 and caused more than 2.6 million deaths worldwide 2 .

In the absence of highly effective clinical treatments and while awaiting mass vaccination, governments have implemented strict policies and public health interventions to contain the pandemic. Those interventions included physical distancing, partial and full lockdowns, and travel-related control measures. The latter include total or partial border closure, airport screening, and quarantine of travelers. A Cochrane review published in June 2020 and updated November 2020 identified a lack of 'real-life' evidence for many travel-control measures since most of the evidence derives from modeling studies 3 .

As countries are facing recurrent waves of infections, it is crucial to map and understand the effectiveness of travel-related policies and contextual factors affecting these policies. The objectives of this study were (1) to map travel policies adopted by countries in response to the pandemic and (2) to systematically review the public health effects of travel policies related to the COVID-19 pandemic and related contextual factors. Our aim is to inform the debate of governments, policy-makers, researchers, and the broader public on whether and how to implement travel policies to control the COVID-19 and similar future pandemics.

We mapped travel restriction policies adopted by 31 countries to address the first objective and conducted a mixed-methods systematic review to address the second objective.

For a pre-determined sample of 31 countries across different regions (table 1), we searched websites of relevant government bodies including ministries of health and ministries of foreign affairs during December 2020. To report on a snapshot of policies adopted during this month, we abstracted data on name of the publishing organization, document access date, and details on policy including type of travel policy, time period, jurisdiction level, exceptions, and level of enforcement. We mapped travel policies over a one-year period (January 2020 to December 2020), using data from the Oxford COVID-19 Government Response Tracker 4 , which collects information on pandemic-related government policy measures. We charted the data by type of travel policy, region and time.

We followed the Cochrane Handbook for Systematic Reviews of Interventions, 5 and the 2020 update of the PRISMA guidelines for reporting systematic reviews 6 .

Population: Human populations exposed to COVID-19, without any restrictions. We did not include studies on populations exposed to SARS and MERS because of the differences in their transmissibility, infectivity and epidemic pattern when compared with COVID-19 7 8 .

Intervention/comparators: We considered policies affecting human travel across jurisdictional (whether national or subnational) borders, relating to any form of travel (air, land or maritime travel), and applied at either the entry or exit through a border. We considered as a policy any statement or position taken by a government or a government department in response to a public problem. Eligible policies included but were not limited to 9 :

 For international travel: screening/testing arrivals, quarantine of arrivals from some or all regions, banning arrivals from some regions, and banning arrivals from all regions or total border closure  For domestic travel: recommendation for not traveling between regions/cities and restrictions on internal movement between regions/cities The comparator could be either the absence of a travel policy, another travel policy, or a nontravel policy (e.g., lockdown, contact tracing in the community).

 Epidemiologic outcomes related to COVID-19: include but are not restricted to number of cases avoided, number of cases detected, positivity rate, change in outbreak pattern (e.g., delay in peak number of infections, flattening of the epidemic curve), transmission rates, spread across countries and regions, mortality rates;  Epidemiological outcomes related to non-COVID-19 infections (e.g., related to influenza infection);

 Health systems outcomes: include but are not restricted to healthcare utilization (e.g. number of cases requiring treatment in the intensive care unit (ICU), time until ICU capacity is reached), health services availability (e.g., number of available intensive care units beds);  Public health capacity: capacity (human and other) of public health agencies to perform contact tracing and testing (e.g. number of tests per day, number of skilled health workers, etc.);  Unintended harms of the interventions of interest.

Also eligible were studies on the following contextual factors:

 Resource requirements, including costs associated with implementing the intervention (e.g., additional personnel, number of tests required), and cost-effectiveness; We excluded studies that did not provide separate data for the effects of the travel policy.

We did not limit eligibility to specific geographical regions, countries, or political systems.

We included randomized controlled trials (RCTs), non-randomized studies (i.e., cohort studies, case-control studies, case series and case reports, interrupted time series), modeling studies, and qualitative studies. We also included research letters and abstracts. We excluded preprints, editorials, letters to editors, commentaries, correspondence.

At the end of December 2020, we searched the following general electronic databases: An information specialist developed the search strategies of different databases (appendix 1).

We used both index terms (where applicable) and free text words for COVID-19 and travel.

We did not limit the search to specific languages. We also screened the reference lists of relevant reviews.

We imported the search results from the different databases to Covidence (https://www.covidence.org/) and removed duplicates. Teams of two reviewers screened titles and abstracts of identified citations in duplicate and independently for potential eligibility.

We retrieved the full text for citations judged as potentially eligible by at least one reviewer.

Full texts were then screened in duplicate and independently. Disagreements were resolved by discussion, or consultation with a third reviewer as needed. Reviewers used standardized and pilot tested screening guides, and conducted a calibration exercise before starting the selection process to ensure validity.

Following calibration exercises where reviewers abstracted the same set of studies and compared their results, one reviewer abstracted data using a standardized and pilot tested form and a second reviewer verified the data. Reviewers resolved disagreements by discussion and with the help of a third reviewer as needed. We abstracted the following information from the included studies: year and language of publication, study design, setting, intervention characteristics (type of travel policy and form of travel addressed, date of policy, level of enforcement), outcomes assessed and related findings.

One reviewer assessed the risk of bias, and a second reviewer verified judgments.

Disagreements were resolved by discussion, or consultation with a third reviewer as needed.

For observational studies, we used the criteria proposed by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) working group 10 . For modeling studies, we adapted a tool from the quality matrix of the EVIDEM framework 11 .

We did not identify any qualitative study and, hence, were not able to conduct a mixedmethods systematic review 12 . A meta-analysis was not possible for quantitative data since included studies were highly heterogeneous in terms of types of interventions, comparators, outcomes assessed and their measures. We rated the certainty of evidence following the GRADE methodology for rating the certainty of evidence in the absence of a single estimate of effect 13 . We did not rate the certainty of the evidence derived from modeling studies since the GRADE working group has not yet operationalized its related guidance.

The mapping of travel policies across 31 countries showed that the four main policies adopted by governments to respond to the COVID-19 pandemic were total and partial border closure, quarantine/isolation of travelers, screening of travelers and passenger forms (Appendix 2a-2e). Partial border closure including travel corridors, mandatory quarantine of travelers, mandatory screening for travelers and requirements to fill a passenger form were among the most widely adopted measures across all the examined countries.

Most countries started to adopt a total border closure measure in March 2020. During April and May 2020, almost 40% of the countries had a bordure closure policy. Starting August 2020, we observed a relaxation in total border closure measures and a transition to partial border closure (ban arrival from some regions), quarantine of and screening arrivals. Figure 1 shows that partial border closure is the most widely used type of travel control measure during 2020.

Travel policies adopted by 31 countries over the period (January 2020 -December 2020) We observed some differences in travel policies across regions ( Figure 2 ). For example, while Australia was stricter in imposing total border closure across the one-year period, Europe was less strict. Table 2 presents the characteristics of included studies. Most of the studies were about effectiveness (n=65; 94%) and were based on statistical modeling (n=4; 72%). The country most assessed by the studies was China (23%), while 32% of the studies examined more than one country. The mostly assessed outcomes were spread across countries and regions (38%), outbreak progression (25%) and number of cases in the community (22%). Table 3 

Appendix 3 and 4 provides details of quality appraisal of modeling and observational studies respectively. Risk of bias was judged to be high for observational studies due to confounding effect in 47% of the studies, and high concern for, or unclear completeness of data in 73% of the studies. The majority of modeling studies did not report on sensitivity analyses (54%). A minority of studies poorly reported on parameters and estimates (12%), and time horizon (16%). No major concerns were noted for the rest of the quality domains.

Findings of included studies on effectiveness (n=65) Table 4 presents the number of observational and modeling studies included for each comparison of interest and the certainty of evidence for the observational studies. The latter was judged to be low to very low (see appendix 5 for evidence profiles of the different comparisons).

In appendix 6, we provide tables for each comparison of interest, detailing for each included study the countries evaluated, the study design, the travel-related policies assessed, the outcomes assessed, and the key findings. In the subsequent text, we summarize the findings in the following order: We included seven observational studies [14] [15] [16] [17] [18] [19] and twenty-four modeling studies .

Two studies evaluated the effect of limitation of air traffic in China imposed during January 2020 15 . Controlling for multiple factors, the authors found that air travel restrictions decreased existing 15 and confirmed 15 cases of COVID-19, and increased recovery rate of COVID-19 15 . This relationship marginally receded as the intervention strength intensified 15 . Three other studies found that border closure decreases the cumulative number of infections 24 25 29 . Three studies found an association between earlier timing and decreased cases 14 39 42 . When modeled, airport reopening in Cyprus with screening maintained was found not to increase cases during a limited period of two weeks 28 .

closure and a reduction in critical cases or overall mortality 14 . Costantino et al. found that the travel ban on travelers from China implemented by Australia close to the peak of the epidemic in China reduced deaths from COVID-19 24 .

Imported diseases: One observational study found that closure of national borders likely decreased 'imported diseases' (e.g. measles, dengue) and influenza cases in Australia 18 .

Border closure was found to slow outbreak spreading across countries 33 , and to decrease the number of imported cases 23 24 36 37 , the 'imported case risk' 39 , the risk flow of importation and exportation across countries 35 , 'cross-country spillovers' 30 , 'epidemic strength' (metric indicating spread potential) 22 , and 'connectedness' between states 19 and countries 16 . Travel ban in Wuhan prevented an increase in the overall cases 40 and virus spread in other regions of China 32 . Earlier timing of this ban was shown to be important 27 34 40 . Border closure in China was also found to reduce case importation to other countries 21 23 36 . On the other hand, while Nakamura et al. found that travel reduction can decrease the risk flow of cases, authors reported that the risk 'still exists' 35 higher local reproduction number 41 or how close the local epidemic is to the 'tipping point for exponential growth' (Rt=0.95-1.05) 37 , higher proportion of imported cases out of local incidence (e.g., higher than 1%) 37 , coupling with other measures to reduce community transmission 21 23 , and implementing the measures as a function infection number 22 .

2. Border closure policy vs. a non-travel policy (n=15)

We included two observational 43 44 and thirteen modeling studies [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] .

One modeling study, Tang et al., found that the quarantine rate of exposed individuals would need to be increased by 100 thousand times to achieve a similar impact as travel restrictions in Beijing 46 . Lifting bordure closure in Germany resulted in minimal to no effect in increasing the daily cases over a 90-day period while lifting contact restriction policies resulted in the highest increase. 51 52 . International travel controls were significantly associated with a reduction in epidemic acceleration across 62 countries 53 and were negatively associated with the initial growth rate of COVID-19 (p = 0.0617) at the early phases of the pandemic 54 . International travel restrictions had larger effect than workplace closure 54 and closure of public transportation 53 and smaller effect than contact tracing and stay-at-home restrictions 55 53 .

Mortality: An observational study found that international travel restrictions at early phase of the pandemic (P <0.001), school closing (P = 0.005) and cancelling public events (P = 0.006) significantly decreased per-capita mortality (while other measures such as workplace closing, restrictions on gatherings, closing public transport, stay-at-home requirements, internal movement restrictions, public information campaigns, testing, and contact tracing were not found to be significant (P > 0.05) 44 . Da Silva et al. found that delaying policies for international travel restrictions led to a higher case fatality rate to similar degrees as public information campaigns and testing. 56 .

We identified four observational [58] [59] [60] [61] and two modeling studies 62 63 .

Three studies, one observational 61 and two modeling 62 63 , found that mandatory quarantine for travelers from high prevalence countries decreased the number of COVID-19 cases per 10,000 people 61 

Three observational studies found that 14-day quarantine of travelers detected nine (0.5%) out of the 1914 travelers who were initially negative at the start of the mandatory quarantine in KSA 58 and nearly half of cases among travelers entering to Japan (5/12) which were missed by symptom-based screening and PCR testing 59 . Mandatory screening of people who are in self-quarantine before their release increased the effectiveness of self-quarantine through detecting COVID-19 cases 60 .

Outbreak progression: One modeling study showed that 2-week isolation for international travelers and their contacts was not effective compared to lockdown and mandatory quarantine in delaying the maximum peak of infection and significantly reducing the total number of infected individuals and deaths 64 .

We included three modeling studies [65] [66] [67] . found that universal screening was unlikely to delay case importation beyond the first 1-3 cases, and often will not delay the first importation at all in any context 66 .

We included two modeling studies. 68 69 Outbreak progression: Mandal et al. found that screening of only symptomatic arrivals would minimally delay the time to epidemic in India, and that screening of at least 75% of asymptomatic individuals -noted by the authors as not feasible-would achieve important delays. Alternatively, quarantining of symptomatic cases in the community was found to have a meaningful effect under an 'optimistic scenario' for COVID-19 transmission 68 . Brethouwer et al. examined a policy named 'stay nearby or get checked', in which individuals that travel and interact with many people are regularly tested. Authors found that this policy brings the second epidemic peak below the first peak and delays its occurrence; while the second wave peak remains above the first with other policies (i.e. social distancing without further regulations) 69 .

We included three modeling studies [70] [71] [72] . 

Wuhan city, expanded to Hubei province) were more effective than airport symptom screening at averting exported cases. The use of health questionnaires was found to catch 95% of cases traveling during the incubation period 70 . Dickens et al. found that quarantine of all travelers for 7 days without pre-release testing, or screening of all passengers with prohibition of entry for those testing positive were less effective policies than quarantine with pre-release testing, or quarantine of all travelers in reducing case importation and secondary cases. Added benefit of pre-release testing was higher when considering 7-day, as compared to 14-day quarantine 72 .

We included two observational 73 74 and two modeling studies 75 76 .

Outbreak progression: In Hong Kong, aggressive escalation of border control including mandatory 14-day quarantine for inbound travelers was correlated with a decrease in the reproduction number (Rt) during the first and second waves of the epidemic 74 . The combination of testing, isolation, contact-tracing and public mask-wearing and physical distancing, without border closure and quarantine of travelers, can suppress R0 to below 1, preventing the imported cases from initiating and escalating domestic transmission 75 .

beginning March 20 in Brunei led to a reduction in the mean duration from symptom onset to diagnosis among imported cases (from 7.3 to 1.3 days, respectively) 73 .

Reopening of borders without quarantine of travelers measures was found to rapidly increase the number of new COVID-19 cases in two provinces in Canada. 76 .

Lifting of travel restrictions was found to lead to a rapid increase in infection spread in 

Four observational studies assessed the contextual factors related to travel policies [77] [78] [79] [80] . Two studies found that the public was supportive of bordure closure policies but showed concerns about the ability of residents to return and the availability of living supplies, including food and household goods and believed that their life was affected by bordure closure 77 78 . One study found the use telehealth can be a cost-effective strategy to provide timely assessment and care for quarantined individuals 80 while one study found no significant impact of sanctions on the compliance rate with self-quarantine 79 .

We identified 69 eligible studies that evaluated the effects of travel-related policies on COVID-19 pandemic, of which four examined contextual factors related to travel policies.

Only a quarter of the studies were observational, while the remaining employed mathematical modeling. Most studies addressed East Asia and South Pacific region. The certainty of the evidence for these studies was judged to be low to very low. Quarantine of travelers may decrease the number of cases of COVID-19 but its effectiveness depends on compliance, and increases when made mandatory. However, lockdown is likely more effective than quarantine of travelers in controlling outbreak progression. Quarantine followed by testing seems to be more effective in reducing spread across countries than quarantine alone, especially when less than 14 day-quarantine is considered. Screening at departure and/or arrival is unlikely to detect a large proportion of cases or to delay an outbreak. Effectiveness of screening may be increased with increased sensitivity of screening test, screening a large proportion of asymptomatic travelers, and exit screening at country source. The effectiveness of screening was also shown to increase when coupled with increasing awareness of travelers on their symptoms and encourage self-reporting. Airport symptom screening seems to be less effective than border closure in decreasing spread across countries.

Although this review highlights the importance of travel policies in containing the COVID-19 pandemic, it found scarcity of evidence assessing acceptability, perceptions and attitudes of the public towards these travel policies. The included studies showed concerns from the public about the availability of living supplies due to border closure and the ability of residents to return home and believed that their life was affected by bordure closure. A review exploring the socio-economic implications of the COVID-19 pandemic showed the devastating impact of travel restrictions on different sectors mainly hospitality, tourism and aviation industries 81 . Another review assessing the impact of mass quarantine including restrictions on local, regional and international travel found that these restrictions can have negative implications on mental health and the economic situations of people. In this regard, public health measures must be complemented with social measures such as physical assistance and social protection schemes to make sure people are protected against the negative implications of restrictions policies 82 . Governments around the world realized the drastic economic and social implications of travel restriction and started relaxing their border closure measures to recover their economy.

This review has two main strengths. First, we have conducted the review using standard, explicit, and rigorous methods and we followed standard methods for reporting systematic reviews. We have run a very comprehensive search using a variety of relevant search words on seven general and COVID-19 specific databases. We also searched published versions of pre-prints and screened reference lists of relevant reviews. One limitation of this review is the use of risk of bias tool for modeling studies that is more about reporting and we might not have been able to capture flaws and associated risk of bias of these studies.

Comparison with other relevant reviews Two previous reviews assessed the effectiveness of travel-control measures to contain the COVID-19 pandemic, and found similar results to our review 3 83 . Table 5 

Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China

WHO. WHO Coranavirus Disease (COVID-19) Dashboard 2021

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

Cochrane Handbook for Systematic Reviews of Interventions. Version 5.1.0 ed: The Cochrane Collaboration

PRISMA 2020 explanation and elaboration: updated guidance and exemplars for reporting systematic reviews

Novel coronavirus 2019-nCoV: prevalence, biological and clinical characteristics comparison with SARS-CoV and MERS-CoV

From SARS and MERS to COVID-19: a brief summary and comparison of severe acute respiratory infections caused by three highly pathogenic human coronaviruses

Implementation of public health genomics in Pakistan

GRADE guidelines: 4. Rating the quality of evidence--study limitations (risk of bias)

Evidence and Value: Impact on DEcisionMaking--the EVIDEM framework and potential applications

Defining and Designing Mixed Research Synthesis Studies

Rating the certainty in evidence in the absence of a single estimate of effect

A country level analysis measuring the impact of government actions, country preparedness and socioeconomic factors on COVID-19 mortality and related health outcomes

The airline transport regulation and development of public health crisis in megacities of China

Analysis of travel restrictions for COVID-19 control in Latin America through network connectedness

The first 100 days of SARS-CoV-2 control in Vietnam

The effect of COVID-19 public health measures on nationally notifiable diseases in Australia: preliminary analysis

Pandemic Risk of COVID-19 Outbreak in the United States: An Analysis of Network Connectedness with Air Travel Data

A data-driven assessment of early travel restrictions related to the spreading of the novel COVID-19 within mainland China

Assessing the impact of reduced travel on exportation dynamics of novel coronavirus infection (Covid-19)

Modeling and interpreting the COVID-19 intervention strategy of China: A human mobility view

The effect of travel restrictions on the spread of the 2019 novel coronavirus (COVID-19) outbreak

The effectiveness of full and partial travel bans against COVID-19 spread in Australia for travellers from China during and after the epidemic peak in China

The dynamics of COVID-19 spread: Evidence from Lebanon

Mobility restrictions for the control of epidemics: When do they work?

Analysis and prediction of the coronavirus disease epidemic in China based on an individual-based model

Response to COVID-19 in Cyprus: policy changes and epidemic trends

The Effects of Border Shutdowns on the Spread of COVID-19

The spatial econometrics of the coronavirus pandemic

A Network-Based Stochastic Epidemic Simulator: Controlling COVID-19 With Region-Specific Policies

Effect of non-pharmaceutical interventions to contain COVID-19 in China

Outbreak dynamics of COVID-19 in Europe and the effect of travel restrictions

Population movement, city closure in Wuhan and geographical expansion of the 2019-nCoV pneumonia infection in China in

Airport risk of importation and exportation of the COVID-19 pandemic

Tracing and analysis of 288 early SARS-CoV-2 infections outside China: A modeling study

The effect of travel restrictions on the geographical spread of COVID-19 between large cities in China: a modelling study

Travel restrictions and sars-cov-2 transmission: An effective distance approach to estimate impact

Impact of population movement on the spread of 2019-nCoV in China

Measuring imported case risk of COVID-19 from inbound international flights ---A case study on

Risk assessment of novel coronavirus COVID-19 outbreaks outside

SARS-Cov-2 trajectory predictions and scenario simulations from a global perspective: a modelling study

Estimating the impact of physical distancing measures in containing COVID-19: An empirical analysis

Association of Country-wide Coronavirus Mortality with Demographics, Testing, Lockdowns, and Public Wearing of Masks

The effects of border control and quarantine measures on the spread of COVID-19

Estimation of the transmission risk of the 2019-nCoV and its implication for public health interventions

Preparing for a future COVID-19 wave: insights and limitations from a data-driven evaluation of non-pharmaceutical interventions in Germany

Optimal Strategies for Control of COVID-19: A Mathematical Perspective

Interplay of social distancing and border restrictions for pandemics via the epidemic renormalisation group framework

The impact of travel and timing in eliminating COVID-19

An investigation of transmission control measures during the first 50 days of the COVID-19 epidemic in China

Mathematical Model of COVID-19 Transmission Dynamics in South Korea: The Impacts of Travel Restrictions, Social Distancing, and Early Detection

Growth Rate and Acceleration Analysis of the COVID-19 Pandemic Reveals the Effect of Public Health Measures in Real Time

The impact of non-pharmaceutical interventions, demographic, social, and climatic factors on the initial growth rate of COVID-19: A cross-country study

Empirical assessment of government policies and flattening of the COVID19 curve

Policy determinants of COVID-19 pandemic-induced fatality rates across nations

Not all interventions are equal for the height of the second peak

Incidence of COVID-19 among returning travelers in quarantine facilities: A longitudinal study and lessons learned

Severe Acute Respiratory Syndrome Coronavirus 2 Infection among Returnees to Japan from Wuhan, China

The Importance of Mandatory COVID-19 Diagnostic Testing Prior to Release from Quarantine

Coronavirus Disease-19: Quarantine Framework for Travelers Entering Korea. Osong public health and research perspectives 2020

Construction of the infection curve of local cases of COVID-19 in hong kong using back-projection

Estimation of the excess covid-19 cases in Seoul, South Korea by the students arriving from China

Forecasting the effect of social distancing on covid-19 autumn-winter outbreak in the metropolitan area of buenos aires

Effectiveness of interventions targeting air travellers for delaying local outbreaks of SARS-CoV-2

Estimated effectiveness of symptom and risk screening to prevent the spread of COVID-19

Effectiveness of airport screening at detecting travelers infected with novel coronavirus (2019-nCoV)

Prudent public health intervention strategies to control the coronavirus disease 2019 transmission in India: A mathematical model-based approach

Stay nearby or get checked": A Covid-19 control strategy

Impact of international travel and border control measures on the global spread of the novel 2019 coronavirus outbreak

Risk assessment and evaluation of China's policy to prevent COVID-19 cases imported by plane

Strategies at points of entry to reduce importation risk of COVID-19 cases and re-open travel

Epidemiological Investigation of the First 135 COVID-19 Cases in Brunei: Implications for Surveillance, Control, and Travel Restrictions

Stringent containment measures without complete city lockdown to achieve low incidence and mortality across two waves of COVID-19 in Hong Kong

The Role of Border Quarantine in National Strategy to Contain COVID-19

Is it safe to lift COVID-19 travel bans? The Newfoundland story

Impact assessment of non-pharmaceutical interventions against coronavirus disease 2019 and influenza in Hong Kong: an observational study

Public Perceptions and Attitudes Toward COVID-19

Nonpharmaceutical Interventions Across Six Countries: A Topic Modeling Analysis of Twitter Data

Self-quarantine non-compliance during the COVID-19 pandemic in South Korea

Use and Cost-Effectiveness of a Telehealth Service at a Centralized COVID-19 Quarantine Center in Taiwan: Cohort Study

The socio-economic implications of the coronavirus pandemic (COVID-19): A review

Social consequences of mass quarantine during epidemics: a systematic review with implications for the COVID-19 response

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