Herpes simplex virus type 2 trends in relation to the HIV epidemic in northern Malawi

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.

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%.

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.

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.