Estimating the number of undetected COVID-19 cases among travellers from mainland China [version 2; peer review: 1 approved, 2 approved with reservations]
oleh: Sangeeta Bhatia, Natsuko Imai, Gina Cuomo-Dannenburg, Marc Baguelin, Adhiratha Boonyasiri, Anne Cori, Zulma Cucunubá, Ilaria Dorigatti, Rich FitzJohn, Han Fu, Katy Gaythorpe, Azra Ghani, Arran Hamlet, Wes Hinsley, Daniel Laydon, Gemma Nedjati-Gilani, Lucy Okell, Steven Riley, Hayley Thompson, Sabine van Elsland, Erik Volz, Haowei Wang, Yuanrong Wang, Charles Whittaker, Xiaoyue Xi, Christl A. Donnelly, Neil M. Ferguson
| Format: | Article |
|---|---|
| Diterbitkan: | Wellcome 2021-09-01 |
Deskripsi
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.