Sero-Prevalence Surveillance to Predict Vaccine-Preventable Disease Outbreaks; A Lesson from the 2014 Measles Epidemic in Northern Vietnam.
Marc Choisy, Son Tung Trinh, Thi Ngoc Diep Nguyen, Tran Hien Nguyen, Quynh Le Mai, Quang Thai Pham, Nhu Duong Tran, Duc Anh Dang, Peter W Horby, Maciej F Boni, Juliet Bryant, Sonia O Lewycka, Behzad Nadjm, H Rogier Van Doorn, Heiman F L Wertheim
Author Information
Marc Choisy: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam. ORCID
Son Tung Trinh: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam.
Thi Ngoc Diep Nguyen: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam.
Tran Hien Nguyen: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Quynh Le Mai: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Quang Thai Pham: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Nhu Duong Tran: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Duc Anh Dang: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
Peter W Horby: Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
Maciej F Boni: Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.
Juliet Bryant: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam.
Sonia O Lewycka: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam.
Behzad Nadjm: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam.
H Rogier Van Doorn: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam.
Heiman F L Wertheim: Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Hanoi, Vietnam.
BACKGROUND: During the first half of 2014, a severe outbreak of measles occurred in northern Vietnam, causing 15 033 confirmed cases and 146 deaths. METHODS: To evaluate the population-level seroprevalence of protection against measles in the period before the outbreak, we made use of an existing age-stratified serum bank, collected over the year before the outbreak, between November 2012 and December 2013, from 4 sites across the country (Hanoi, Hue, Dak Lak, and Ho Chi Minh City). Data from the UNICEF's Multiple Indicator Clustered Surveys (MICS), carried out in Vietnam during the first quarter of 2014, were used to assess the vaccine coverage in 6 ecological regions of Vietnam. RESULTS: Results revealed a large discrepancy between levels of protection, as estimated from the serology and vaccine coverage estimated by UNICEF's MICS. Variation in seroprevalence across locations and age groups corresponded with reported numbers of measles cases, most of which were among the 0-2-year-old age group and in the northern part of the country. CONCLUSIONS: Our study presents a strong case in favor of a serosurveillance sentinel network that could be used to proactively tune vaccination policies and other public health interventions.
