Herpes simplex virus type 2 trends in relation to the HIV epidemic in northern Malawi
- 1Infectious Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, London, UK
- 2Karonga Prevention Study, PO Box 46, Chilumba, Malawi
- Professor J Glynn, Infectious Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK;
- Accepted 24 April 2008
- Published Online First 4 June 2008
Objectives: It is unclear whether the high prevalence of herpes simplex virus type 2 (HSV-2) found in much of Africa predates the HIV epidemic or is, to some extent, a consequence of it. HSV-2 prevalence trends in a rural African community were assessed over a period in which HIV prevalence rose sharply, and antenatal clinic (ANC) surveillance was explored as a method of estimating community HSV-2 prevalence.
Methods: HSV-2 seroprevalence was determined among community controls seen for case–control studies of mycobacterial disease in Karonga district, Malawi, in 1988–90, 1998–2001 and 2002–5, and in women attending ANC as part of surveillance for HIV in 1999–2000. Over this period HIV prevalence rose from 4% to 12%.
Results: HSV-2 prevalence in all periods increased sharply with age and was higher in women than in men. After excluding migrants, there was no evidence of change in HSV-2 prevalence in the different periods. Women in the ANC group had lower HSV-2 prevalence than those in the community, but the ANC prevalence was a good approximation to the combined male and female prevalence for the same age group.
Conclusions: This study suggests that HSV-2 was already widespread before the HIV epidemic and has not been greatly influenced by it. It also demonstrates that ANC surveillance may be useful for estimating community HSV-2 prevalence.
Funding: Until 1996 the Karonga Prevention Study was funded primarily by the British Leprosy Relief Association (LEPRA) and the International Federation of Anti-Leprosy Organizations (ILEP) with contributions from the WHO/UNDP/World Bank Special Programme for Research and Training in Tropical Diseases. Since 1996 the Wellcome Trust has been the principal funder and funded this project. JRG was supported by the UK Department of Health (Public Health Career Scientist award).
Competing interests: None.
Ethics approval: Permission for the original studies, and testing of the stored sera for HSV-2, was received from the Health Sciences Research Committee, Malawi, and from the ethics committee of the London School of Hygiene and Tropical Medicine.
Patient consent: Obtained.
Contributors: The study was designed by JRG, ACC and PEMF. The case–control studies were led by ACC, with OM, and the ANC study by BMMN. RN led the HSV-2 testing. JRG led the analyses and wrote the first draft of the paper. All authors contributed to the writing of the paper.