The prevalence of SARS-CoV-2 antibodies in quarantine workers and high-risk communities in Vietnam

Tasnim Hasan; Pham Ngoc Thach; Nguyen Thu Anh; Le Thi Thu Hien; Nguyen Thi Mai An; Dang Thi Thuy; Le Van Duyet; Nguyen Thi Dung; Tran Thi Diep; Hoang Van Huynh; Brett G Toelle; Guy B Marks; Greg J Fox

doi:10.1016/j.ijregi.2021.12.001

The prevalence of SARS-CoV-2 antibodies in quarantine workers and high-risk communities in Vietnam

IJID Reg. 2022 Mar:2:137-140. doi: 10.1016/j.ijregi.2021.12.001. Epub 2021 Dec 11.

Authors

Tasnim Hasan^{1

2}, Pham Ngoc Thach³, Nguyen Thu Anh², Le Thi Thu Hien², Nguyen Thi Mai An⁴, Dang Thi Thuy³, Le Van Duyet³, Nguyen Thi Dung⁵, Tran Thi Diep⁵, Hoang Van Huynh⁶, Brett G Toelle^{1

2

7}, Guy B Marks^{2

8}, Greg J Fox^{1

2}

Affiliations

¹ Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia.
² The Woolcock Institute of Medical Research, Glebe, NSW 2037, Australia.
³ National Hospital for Tropical Diseases, Hanoi, Vietnam.
⁴ Department of Planning and Finance, Ministry of Health.
⁵ Quang Ninh Center for Disease Control, Quang Ninh, Vietnam.
⁶ Hai Duong Centre for Disease Control, Hai Duong, Vietnam.
⁷ Sydney Local Health District, NSW, Australia.
⁸ South Western Sydney Clinical School, The University of New South Wales, Liverpool, NSW, Australia.

Abstract

Objective: The aim of this study was to determine the seroprevalence of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibodies in high-risk communities and quarantine workers in Vietnam.

Methods: The prevalence of SARS-CoV-2 antibodies was measured in household contacts, close contacts, community members, and migrant workers from two sub-communes in which COVID-19 outbreaks occurred in early 2021: Bac Ma 1 and Tien. The prevalence of SARS-CoV-2 antibodies was also evaluated among quarantine workers at two facilities responsible for quarantining of contacts of COVID-19 cases.

Results: Among 2069 participants from the two sub-communes, six individuals (0.3%) had detectable SARS-CoV-2 antibodies despite no history of COVID-19. This included one Vietnamese migrant worker, two community members, two household contacts, and one close contact of known COVID-19 cases. Among 50 workers at two COVID-19 quarantine facilities, including 15 health care workers (HCWs), one of the HCWs tested positive for SARS-CoV-2 antibodies (1/50, 2.0%) despite no known disease.

Conclusion: The prevalence of SARS-CoV-2 antibodies was low in Vietnamese 'hotspots', suggesting limited community transmission.