INVESTIGATION OF A MEASLES OUTBREAK IN CHINA TO IDENTIFY GAPS IN VACCINATION COVERAGE, ROUTES OF TRANSMISSION, AND INTERVENTIONS

Monday, 27th of July 2015

INVESTIGATION OF A MEASLES OUTBREAK IN CHINA TO IDENTIFY GAPS IN VACCINATION COVERAGE, ROUTES OF TRANSMISSION, AND INTERVENTIONS

 

• Xiang Zheng, 
• Ningjing Zhang, 
• Xiaoshu Zhang, 
• Lixin Hao, 
• Qiru Su, 
• Haijun Wang, 
• Kongyan Meng, 
• Binglin Zhang, 
• Jianfeng Liu,  …
• Huaqing Wang

• Published: July 24, 2015
• DOI: 10.1371/journal.pone.0133983

Abstract below; full text, with figures, is at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0133983

Background

A measles outbreak occurred in a western county of China in 2013, the year after Chinas historic nadir of measles. We conducted a field investigation to identify gaps in measles vaccination coverage and immunization program weaknesses, and to provide recommendations for measles outbreak response and immunization program improvement.

Methods

We analyzed surveillance data from 2008 to 2013 to describe the measles epidemiology of the county. Measles-containing vaccine coverage was estimated using two methods: previously-reported administrative coverage and an estimation of coverage by clinic-kept vaccination records (n = 542). We conducted a rapid field coverage assessment in a migrant population village to evaluate coverage after emergency vaccination. We conducted a review of hospital records of measles cases to address the role hospital transmission played during the early stage of this outbreak.

Results

There were 153 cases in the outbreak, primarily among children too young to vaccinate, unvaccinated children less than 3 years old, and adults. Measles-containing vaccine coverage by the field assessment showed that 20% of children aged 8–17 months had zero doses, and 9% of ≥2 years old children had fewer than two doses. The vaccination statuses of all adult cases were either zero doses or unknown. At least 61% of cases had been hospitalized. The proportion of cases who had been hospital-exposed 7 to 21 days prior to rash onset decreased from 52% to 22% after hospitals strengthen their isolation measures.

Conclusions

This outbreak was a result of measles vaccination coverage gaps among young children and adults, and insufficient hospital isolation of cases. The lower coverage seen in the field estimation compared with reported coverage showed that reported coverage could have been overestimated. Hospitals were sites of transmission in the early stage of the outbreak. A strict hospital isolation policy could decrease spread of measles. Emergency vaccination was associated with stopping measles transmission in low coverage areas.

Citation: Zheng X, Zhang N, Zhang X, Hao L, Su Q, Wang H, et al. (2015) Investigation of a Measles Outbreak in China to Identify Gaps in Vaccination Coverage, Routes of Transmission, and Interventions. PLoS ONE 10(7): e0133983. doi:10.1371/journal.pone.0133983

Editor: Yang Yang, University of Florida, UNITED STATES

Received: September 14, 2014; Accepted: July 4, 2015; Published: July 24, 2015

Copyright: © 2015 Zheng et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Data Availability: Relevant data are within the paper and its Supporting Information files.

Funding: Funding to support the field investigation activities described in this paper came from national, provincial, and local governments of China for routine EPI work, as part of the authors responsibility and routine work. The authors wrote this paper as part of their routine responsibilities as medical officers in the Chinese Centers for Disease Control. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.