Original articles

Measles outbreak in South Africa, 2003-2005

Meredith Lynn McMorrow, Goitom Gabremedhin, Johann van den Heever, Robert Kezaala, Bernice Harris, Robin Nandy, Peter Strebel, Abdoulie Jack, Karen Lisa Cairns

Abstract


Objectives: Measles was virtually eliminated in South Africa following control activities in 1996-7. However, from July 2003 – November 2005, 1676 laboratory-confirmed measles cases were reported in South Africa. We investigated the outbreak’s cause and the role of HIV.
Design: We traced laboratory-confirmed case-patients residing in Johannesburg Metropolitan (JBM) and O.R. Tambo districts. We interviewed laboratory- or epidemiologically-confirmed case-patients or their caregivers to determine vaccination status and, in JBM, HIV status. We calculated vaccine effectiveness using the screening method.
Setting: Household survey in JBM and O.R. Tambo districts
Outcome measures: Vaccine effectiveness, case-fatality rate, and hospitalizations.
Results: In JBM, 109 case-patients were investigated. Of the 57 case-patients eligible for immunization, 27 (47.4%) were vaccinated. Fourteen (12.8%) case-patients were HIV-infected, 46 (42.2%) were HIV-uninfected, and 49 (45.0%) had unknown HIV status. Among children aged 12-59 months, vaccine effectiveness was 85% (95% CI: 63, 94) for all children, 63% for HIV-infected, 75% for HIV-uninfected and 96% for children with unknown HIV status*. In O.R. Tambo, 157 case-patients were investigated. Among the 138 case-patients eligible for immunization, 41 (29.7%) were vaccinated. Vaccine effectiveness was 89% (95% CI: 77, 95).
Conclusions: The outbreak’s primary cause was failure to vaccinate enough of the population to prevent endemic measles transmission. Although vaccine effectiveness may have been lower in HIV-infected than uninfected children, population vaccine effectiveness remained high.
Key Words: measles, HIV, vaccines
* Confidence intervals were not calculated for sub-groups due to small sample size.

Authors' affiliations

Meredith Lynn McMorrow, U.S. Centers for Disease Control and Prevention

Goitom Gabremedhin, World Health Organization Regional Office for Africa, Vaccine Preventable Diseases, Harare Zimbabwe

Johann van den Heever, Expanded Programme on Immunisation, Department of Health, Pretoria, South Africa

Robert Kezaala, Department of Immunization, Vaccines, and Biologicals, World Health Organization, Geneva Switzerland

Bernice Harris, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg South Africa

Robin Nandy, Health Section, United Nations Children’s Fund, New York, NY

Peter Strebel, Department of Immunization, Vaccines, and Biologicals, World Health Organization, Geneva Switzerland

Abdoulie Jack, Acting WHO Representative in Nigeria

Karen Lisa Cairns, US Centers for Disease Control and Prevention

Full Text

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Keywords

measles, HIV, vaccines

Cite this article

South African Medical Journal 2009;99(5):314.

Article History

Date submitted: 2008-08-26
Date published: 2009-05-08

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