Association of public health interventions and COVID-19 incidence in Vietnam, January to December 2020.
Ha-Linh Quach, Khanh Cong Nguyen, Ngoc-Anh Hoang, Thai Quang Pham, Duong Nhu Tran, Mai Thi Quynh Le, Hung Thai Do, Chien Chinh Vien, Lan Trong Phan, Nghia Duy Ngu, Tu Anh Tran, Dinh Cong Phung, Quang Dai Tran, Tan Quang Dang, Duc-Anh Dang, Florian Vogt
Author Information
Ha-Linh Quach: Department of Epidemiology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam; National Centre for Epidemiology and Population Health, Research School of Population Health, College of Health and Medicine, Australian National University, Canberra, ACT, Australia.
Khanh Cong Nguyen: Department of Epidemiology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam. Electronic address: nck@nihe.org.vn.
Ngoc-Anh Hoang: Department of Epidemiology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam; National Centre for Epidemiology and Population Health, Research School of Population Health, College of Health and Medicine, Australian National University, Canberra, ACT, Australia. Electronic address: ngoc-anh.hoang@anu.edu.au.
Thai Quang Pham: Department of Epidemiology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam; School of Preventive Medicine and Public Health, Hanoi Medical University, Hanoi, Vietnam.
Duong Nhu Tran: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Mai Thi Quynh Le: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Hung Thai Do: Nha Trang Pasteur Institute, Nha Trang City, Khanh Hoa, Vietnam.
Chien Chinh Vien: Tay Nguyen Institute of Hygiene and Epidemiology, Dak Lak, Vietnam.
Lan Trong Phan: Ho Chi Minh Pasteur Institute, Ho Chi Minh City, Vietnam.
Nghia Duy Ngu: Department of Epidemiology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Tu Anh Tran: Department of Epidemiology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Dinh Cong Phung: National Agency for Science and Technology Information, Ministry of Science and Technology, Hanoi, Vietnam.
Quang Dai Tran: General Department of Preventive Medicine, Ministry of Health, Hanoi, Vietnam.
Tan Quang Dang: General Department of Preventive Medicine, Ministry of Health, Hanoi, Vietnam.
Duc-Anh Dang: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Florian Vogt: National Centre for Epidemiology and Population Health, Research School of Population Health, College of Health and Medicine, Australian National University, Canberra, ACT, Australia; The Kirby Institute, University of New South Wales, Sydney, NSW, Australia.
BACKGROUND: Vietnam implemented various public health interventions such as contact tracing and testing, mandatory quarantine, and lockdowns in response to coronavirus disease 2019 (COVID-19). However, the effects of these measures on the epidemic remain unclear. METHODS: This article describes the public health interventions in relation to COVID-19 incidence. Maximum likelihood estimations were used to assess containment delays (time between symptom onset and start of isolation) and multivariable regression was employed to identify associated factors between interventions and COVID-19 incidence. The effective reproductive numbers (Rt) were calculated based on transmission pairs. RESULTS: Interventions were introduced periodically in response to the epidemic. Overall, 817 (55.4%) among 1474 COVID-19 cases were imported. Based on a serial interval of 8.72 ± 5.65 days, it was estimated that Rt decreased to below 1 (lowest at 0.02, 95% CI 0-0.12) during periods of strict border control and contact tracing, and increased ahead of new clusters. The main method to detect cases shifted over time from passive notification to active case-finding at immigration or in lockdown areas, with containment delays showing significant differences between modes of case detection. CONCLUSIONS: A combination of early, strict, and consistently implemented interventions is crucial to control COVID-19. Low-middle income countries with limited capacity can contain COVID-19 successfully using non-pharmaceutical interventions.
