Estimating internationally imported cases during the early COVID-19 pandemic

Menkir, Tigist F.; Chin, Taylor; Hay, James A.; Surface, E D; Salazar, Pablo; Buckee, Caroline O.; Watts, Alexander; Khan, Kamran; Sherbo, Ryan; Yan, Aimin; Mina, Michael J.; Lipsitch, Marc; Niehus, René

doi:10.1038/s41467-020-20219-8

Cited by 40 publications

(35 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, human mobility was recognized to be the source of the early epidemic growth rate in China ( Kraemer et al, 2020 ). Menkir et al (2021) argued that predictions of international outbreaks were mainly based on imported cases from Wuhan (China), potentially missing imports from other cities. The model used by these scholars suggests that some COVID-19 cases were imported to African destinations and 90% of imported cases arrived between the 17 th of January and the 7 th of February 2020, before the first case detections.…”

Section: Introductionmentioning

confidence: 99%

Can commercial trade represent the main indicator of the COVID-19 diffusion due to human-to-human interactions? A comparative analysis between Italy, France, and Spain

Bontempi

Coccia

Vergalli

et al. 2021

Environmental Research

View full text Add to dashboard Cite

The main goal of this study is to analyze the relation between commercial trade and pandemic severity in society, in order to support new hypotheses which can explain transmission dynamics of COVID-19, as well as promote policy responses to cope with future epidemics similar to COVID-19. This study considers the role of trade in the dynamics of pandemic diffusion, within and between countries, which has not been investigated yet in this emerging field of research. We focus on three large countries in Europe: Italy, France, and Spain. The analysis is performed at regional level (involving in total 52 European regions). Results suggest that the association between trade and pandemic severity seems to be supported by empirical evidence, making it possible to introduce new hypotheses for explaining transmission dynamics of COVID-19 within and between countries. In particular, international trade data is supposed to be used as a comprehensive indicator accounting for population density, economic dynamism, and human mobility. The statistical analyses, also in a multivariate context, strongly support this hypothesis and suggest that crisis management has to focus in the very first place on infections occurring outside the national boundaries, in order to cope with pandemic threat of new waves of COVID-19 and future similar epidemics/pandemics.

show abstract

Section: Introductionmentioning

confidence: 99%

Can commercial trade represent the main indicator of the COVID-19 diffusion due to human-to-human interactions? A comparative analysis between Italy, France, and Spain

Bontempi

Coccia

Vergalli

et al. 2021

Environmental Research

View full text Add to dashboard Cite

show abstract

“…At the beginning of the coronavirus disease 2019 (COVID-19) pandemic, travellers formed a high proportion of total incidence, 1 , 2 leading countries to impose travel restrictions, border closures, quarantining of travellers, temperature screening and, when tests became available, testing protocols. 3 , 4 The virus responsible, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can undergo genomic rearrangement and has structural advantages to spread easily between hosts, 5 thus has facilitated for ongoing widespread community transmission globally.…”

Section: Introductionmentioning

confidence: 99%

Determining quarantine length and testing frequency for international border opening during the COVID-19 pandemic

Dickens¹,

Koo

Lim

et al. 2021

Journal of Travel Medicine

View full text Add to dashboard Cite

Background The COVID-19 pandemic has resulted in the closure or partial closure of international borders in almost all countries. Here we investigate the efficacy of imported case detection considering quarantine length and different testing measures for travellers on arrival. Methods We examine 8 broad border control strategies from utilising quarantine alone, pretesting, entry and exit testing, and testing during quarantine. In comparing the efficacy of these strategies, we calculate the probability of detecting travellers who have been infected up to 2 weeks pre-departure according to their estimated incubation and infectious period. We estimate the number of undetected infected travelers permitted entry for these strategies across a prevalence range of 0.1%–2% per million travelers. Results At 14-day quarantine, on average 2.2% (Range: 0.5%–8.2%) of imported infections are missed across the strategies, leading to 22 (5–82) imported cases at 0.1% prevalence per million travellers, increasing up to 430 (106–1641) at 2%. The strategy utilising exit testing results in 3.9% (3.1%–4.9%) of imported cases being missed at 7-day quarantine, down to 0.4% (0.3%–0.7%) at 21-day quarantine, and the introduction of daily testing, as the most risk averse strategy, reduces the proportion further to 2.5%–4.2% at day 7 and 0.1–0.2% at day 21 dependent on the tests used. Rapid antigen testing every 3 days in quarantine leads to 3% being missed at 7 days and 0.7% at 14 days, which is comparable to PCR testing with a 24-hour turnaround. Conclusions Mandatory testing, at a minimal of pre-testing and on arrival, is strongly recommended where the length of quarantining should then be determined by the destination country’s level of risk averseness, pandemic preparedness and origin of travellers. Repeated testing during quarantining should also be utilised to mitigate case importation risk and reduce the quarantining duration required.

show abstract

“…Another evident predictor variable is transportation. The virus spread to different countries has been attributed to air travellers [7,[56][57][58][59][60][61][62][63]. The surrounding areas of transport hubs such as airports and large train stations should witness the appearance of the virus earlier than other less connected zones, increasing its transmission [43,[64][65][66][67].…”

Section: Introductionmentioning

confidence: 99%

Early Spread of COVID-19 in the Air-Polluted Regions of Eight Severely Affected Countries

Pansini

Fornacca

2021

Atmosphere

View full text Add to dashboard Cite

COVID-19 escalated into a pandemic posing several humanitarian as well as scientific challenges. We here investigated the geographical character of the early spread of the infection and correlated it with several annual satellite and ground indexes of air quality in China, the United States, Italy, Iran, France, Spain, Germany, and the United Kingdom. The time of the analysis corresponded with the end of the first wave infection in China, namely June 2020. We found more viral infections in those areas afflicted by high PM 2.5 and nitrogen dioxide values. Higher mortality was also correlated with relatively poor air quality. In Italy, the correspondence between the Po Valley pollution and SARS-CoV-2 infections and induced mortality was the starkest, originating right in the most polluted European area. Spain and Germany did not present a noticeable gradient of pollution levels causing non-significant correlations. Densely populated areas were often hotspots of lower air quality levels but were not always correlated with a higher viral incidence. Air pollution has long been recognised as a high risk factor for several respiratory-related diseases and conditions, and it now appears to be a risk factor for COVID-19 as well. As such, air pollution should always be included as a factor for the study of airborne epidemics and further included in public health policies.

show abstract

Estimating internationally imported cases during the early COVID-19 pandemic

Cited by 40 publications

References 24 publications

Can commercial trade represent the main indicator of the COVID-19 diffusion due to human-to-human interactions? A comparative analysis between Italy, France, and Spain

Can commercial trade represent the main indicator of the COVID-19 diffusion due to human-to-human interactions? A comparative analysis between Italy, France, and Spain

Determining quarantine length and testing frequency for international border opening during the COVID-19 pandemic

Early Spread of COVID-19 in the Air-Polluted Regions of Eight Severely Affected Countries

Contact Info

Product

Resources

About