The proportion of cases of genital ulcer disease attributable to herpes simplex virus type 2 (HSV-2) appears to be increasing in sub-Saharan Africa.
To assess the contributions of HIV disease and behavioral response to the HIV epidemic to the increasing proportion of genital ulcer disease (GUD) attributable to HSV-2 in sub-Saharan Africa.
Simulations of the transmission dynamics of ulcerative sexually transmitted diseases (STDs) and HIV with use of the model STDSIM.
In simulations, 28% of GUD was caused by HSV-2 before a severe HIV epidemic. If HIV disease was assumed to double the duration and frequency of HSV-2 recurrences, this proportion rose to 35% by year 2000. If stronger effects of HIV were assumed, this proportion rose further, but because of increased HSV-2 transmission this would shift the peak in HSV-2 seroprevalence to an unrealistically young age. A simulated 25% reduction in partner-change rates increased the proportion of GUD caused by HSV-2 to 56%, following relatively large decreases in chancroid and syphilis.
Behavioral change may make an important contribution to relative increases in genital herpes.
Modeling scenarios suggest that behavioral responses to the HIV epidemic may have contributed markedly to observed increases in the proportion of genital ulcer disease due to herpes simplex virus type 2 in sub-Saharan Africa.
From the *Department of Public Health, Faculty of Medicine, Erasmus University, Rotterdam, Rotterdam, The Netherlands; †GlaxoSmithKline, Greenford, United Kingdom; and ‡London School of Hygiene and Tropical Medicine, London, United Kingdom
The authors thank Nico Nagelkerke and Kate Orroth for useful comments on the manuscript. We are also grateful to Frances Cowan and Richard White for advice on the HSV-2 model representation.
The study was financially supported by Glaxo Wellcome Research and Development.
Correspondence: Eline L. Korenromp, Department of Public Health, Faculty of Medicine, Erasmus University, Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands. E-mail: email@example.com
Received for publication June 5, 2001,
revised August 14, 2001, and accepted August 17, 2001.