Rubella outbreak and outbreak management in a school setting, China, 2014
Background: An active response to a rubella outbreak may interrupt disease transmission, and outbreak response immunization (ORI) can increase immunity among persons who might otherwise not be protected. On March 17, 2014, a rubella outbreak was reported in a middle school in Guangzhou city, China....
Main Authors: | , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Taylor & Francis Group
2017-04-01
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Series: | Human Vaccines & Immunotherapeutics |
Subjects: | |
Online Access: | http://dx.doi.org/10.1080/21645515.2016.1252494 |
Summary: | Background: An active response to a rubella outbreak may interrupt disease transmission, and outbreak response immunization (ORI) can increase immunity among persons who might otherwise not be protected. On March 17, 2014, a rubella outbreak was reported in a middle school in Guangzhou city, China. We conducted an investigation to assess impact of a policy of exclusion of cases from school and of ORI. Methods: Active surveillance was used to find cases of rubella. Investigators interviewed teachers and reviewed the absentee records to determine implementation details of school exclusion. ORI was recommended on 2 occasions during the outbreak, one small-scale and one large-scale. Laboratory confirmation tests included serum IgM and IgG measurements to distinguish between acute infection and immunity. A serological survey in 4 classes was used to determine immunity status and identify symptomatic and asymptomatic cases. Results: From February 17 to May 23, 2014, 162 rubella cases (24 laboratory-confirmed and 138 epidemiologically linked) were detected among 1,621 students. Cases ultimately occurred in 27 classes (72.97%) across 37 classes. In 11 classes in which exclusion from school was delayed by 1 or more days, the secondary attack rate was 12.30%, compared with 2.35% in 15 classes with immediate exclusion. ORI increased vaccine coverage from 25.83 % to 86.92%, and the final case of the epidemic was reported one month later. A serological survey of 91 students in 4 classes identified 15 cases, 6 of which were asymptomatic. Conclusions: The outbreak happened in school with low rubella-containing vaccination coverage. Exclusion from school upon rash/fever onset was associated with lowering the secondary attack rate, but school exclusion alone was not able to stop this outbreak – a large ORI was needed. Assuring complete vaccination upon entry to school is likely to be necessary to ensure coverage is above the herd immunity threshold and prevent outbreaks from happening. |
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ISSN: | 2164-5515 2164-554X |