PROPORTION OF HIV-INFECTIONS ATTRIBUTABLE TO ETHER SEXUALLY-TRANSMITTED DISEASES IN A RURAL UGANDAN POPULATION - SIMULATION-MODEL ESTIMATES

Background. Unprotected heterosexual contact in the presence of other sexually transmitted diseases (STD) enhances the probability of HIV tr ansmission. The objective of this study was to estimate the proportion of HIV infections attributable to STD in rural Uganda. Methods. Simul ation modelling scenarios of the transmission dynamics of HIV infectio n and of ulcerative and non-ulcerative STD were employed to address th is objective, drawing on data from a specific rural population cohort of 10000 in south-west Uganda. Results, In simulations of the initial 10-year period of the HIV epidemic (1980-1990), over 90% of HIV infect ions were attributed to STD. Even given conservative assumptions about the prevalence of STD and about their enhancing effects on HIV transm ission, STD played a critical role in the rapid and extensive spread o f HIV infection. The role of STD decreased with progression of the HIV epidemic. Conclusions. In developing countries, control of the spread of HIV infection may benefit substantially from successful STD interv ention programmes, and particularly in areas where HIV infection is no t already well established.