TY - JOUR
T1 - Estimating the number of undetected COVID-19 cases among travellers from mainland China
AU - Donnelly, Christl A.
AU - Bhatia, Sangeeta
AU - Imai, Natsuko
AU - Cuomo-Dannenburg, Gina
AU - Baguelin, Marc
AU - Boonyasiri, Adhiratha
AU - Cori, Anne
AU - Cucunubá, Zulma
AU - Dorigatti, Ilaria
AU - FitzJohn, Rich
AU - Fu, Han
AU - Gaythorpe, Katy
AU - Ghani, Azra
AU - Hamlet, Arran
AU - Hinsley, Wes
AU - Laydon, Daniel
AU - Nedjati-Gilani, Gemma
AU - Okell, Lucy
AU - Riley, Steven
AU - Thompson, Hayley
AU - van Elsland, Sabine
AU - Volz, Erik
AU - Wang, Haowei
AU - Wang, Yuanrong
AU - Whittaker, Charles
AU - Xi, Xiaoyue
AU - Ferguson, Neil M.
N1 - Publisher Copyright:
© 2021 Bhatia S et al.
PY - 2021
Y1 - 2021
N2 - Background: As of August 2021, every region of the world has been affected by the COVID-19 pandemic, with more than 196,000,000 cases worldwide. Methods: We analysed COVID-19 cases among travellers from mainland China to different regions and countries, comparing the region- and country-specific rates of detected and confirmed cases per flight volume to estimate the relative sensitivity of surveillance in different regions and countries. Results: Although travel restrictions from Wuhan City and other cities across China may have reduced the absolute number of travellers to and from China, we estimated that up to 70% (95% CI: 54% - 80%) of imported cases could remain undetected relative to the sensitivity of surveillance in Singapore. The percentage of undetected imported cases rises to 75% (95% CI 66% - 82%) when comparing to the surveillance sensitivity in multiple countries. Conclusions: Our analysis shows that a large number of COVID-19 cases remain undetected across the world. These undetected cases potentially resulted in multiple chains of human-to-human transmission outside mainland China.
AB - Background: As of August 2021, every region of the world has been affected by the COVID-19 pandemic, with more than 196,000,000 cases worldwide. Methods: We analysed COVID-19 cases among travellers from mainland China to different regions and countries, comparing the region- and country-specific rates of detected and confirmed cases per flight volume to estimate the relative sensitivity of surveillance in different regions and countries. Results: Although travel restrictions from Wuhan City and other cities across China may have reduced the absolute number of travellers to and from China, we estimated that up to 70% (95% CI: 54% - 80%) of imported cases could remain undetected relative to the sensitivity of surveillance in Singapore. The percentage of undetected imported cases rises to 75% (95% CI 66% - 82%) when comparing to the surveillance sensitivity in multiple countries. Conclusions: Our analysis shows that a large number of COVID-19 cases remain undetected across the world. These undetected cases potentially resulted in multiple chains of human-to-human transmission outside mainland China.
KW - COVID-19
KW - Epidemiology
KW - International
KW - Novel coronavirus
KW - SARS-CoV-2
UR - https://www.scopus.com/pages/publications/85116649961
U2 - 10.12688/wellcomeopenres.15805.2
DO - 10.12688/wellcomeopenres.15805.2
M3 - Article
AN - SCOPUS:85116649961
SN - 2398-502X
VL - 5
JO - Wellcome Open Research
JF - Wellcome Open Research
M1 - 143
ER -