Understanding the transmission dynamics of a large-scale measles outbreak in Southern Vietnam

Autor: Thi Huyen Trang Nguyen, Thuong Vu Nguyen, Quang Chan Luong, Thang Vinh Ho, Christel Faes, Niel Hens
Přispěvatelé: NGUYEN, Trang, Nguyen, Thuong Vu, Luong, Quang Chan, Ho, Thang Vinh, FAES, Christel, HENS, Niel
Rok vydání: 2022
Předmět:
Zdroj: International journal of infectious diseases
ISSN: 1878-3511
1201-9712
Popis: Objectives: Southern Vietnam experienced a large measles outbreak of over 26,0 0 0 cases during 20182020. We aimed to understand and quantify the measles spread in space-time dependence and the transmissibility during the outbreak.Methods: Measles surveillance reported cases between January 2018 and June 2020, vaccination coverage, and population data at provinicial level were used. To illustrate the spatio-temporal pattern of disease spread, we employed the endemic-epidemic multivariate time series model decomposing measles risk additively into autoregressive, spatio-temporal, and endemic components. Likelihood-based estimation procedures were performed to determine the time-varying reproductive number R e of measles. Results: Our analysis showed that the incidence of measles was associated with vaccination coverage heterogeneity and spatial interaction between provincial units. The risk of infections was dominated by between-province transmission (36.1% to 78.8%), followed by local endogenous transmission (4.1% to 61.5%). In contrast, the endemic behavior had a relatively small contribution (2.4% to 33.4%) across provinces. In the exponential phase of the epidemic, R e was above the threshold with a maximum value of 2.34 (95% CI: 2.20-2.46).Conclusion: Local vaccination coverage and human mobility are important factors contributing to the measles dynamics in Southern Vietnam, and the high risk of inter-provincial transmission is of most concern. Strengthening the disease surveillance is recommended, and further research is essential to understand the relative contribution of population immunity and control measures in measles epidemics. (c) 2022 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. We would like to thank the VLIR-UOS for awarding T.H.T.N. a scholarship to study the Master of Epidemiology at the University of Antwerp, Belgium. We are pleased to acknowledge the Pasteur Institute in Ho Chi Minh City including the Board of Directors for supporting the research endeavor in terms of data use, colleagues of the Outbreak Control Unit (Pham Duy Quang, Nguyen Thi Phuong Thuy, Tran Cong Kha, Doan Ngoc Minh Quan, Nguyen Quoc Kien, Tran Anh Tuan, Phan Thi Ngoc Uyen, Nguyen Viet Thinh, Hoang Thi Lien, and Phan Cong Hung), and the EPI Unit (Hoang Anh Thang, Chau Van Luom, Truong Cong Hieu, Vo Ngoc Quang, Nguyen Dieu Thuy, Nguyen Thi Huyen, Phan Thi Quynh Tram, Vien Dang Khanh Linh, Nguyen Thi Thu Trang, Nguyen Van Hoang, Tran Quang Trung, Trinh Trung Truc, Tran Thanh Hai) for their huge efforts and enthusiasm in case monitoring, surveillance and contact tracing, outbreak investigation, and launching the supplementary immunization activities during the measles outbreak. We would also like to acknowledge the large contribution of 20 Provincial Centers for Disease Control and Prevention in two cities and 18 provinces in Southern Vietnam in the EPI National Project.
Databáze: OpenAIRE
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