HIV/AIDS is a disease for which we ourselves are the vector. Consequently, a high prevalence of the disease in the population is likely to generate a high incidence of new infections. This paper argues that in Sub-Saharan Africa, where the prevalence of other fatal diseases is high, there is a counter-intuitive effect of health care spending: such spending increases the life expectancy of the infected, and so drives up the prevalence of HIV in the population. The link between prevalence and incidence implies that high-quality health care may thus inadvertently increase HIV transmission, leading to elevated HIV prevalence in the course of an epidemic