Routinely reported sexually transmitted diseases presage the evolution of the AIDS epidemic.

Because AIDS is largely transmitted through sexual intercourse, the descriptive epidemiology of sexually transmitted diseases of short incubation period could presage the incidence trend of AIDS after a time interval that approximates the incubation period of the disease. We have evaluated this hypothesis using data from the 50 states in the United States routinely reported to the Centers of Disease Control and Prevention from 1979 to 1994. We have estimated the dependence of the slope of the annual incidence rate of AIDS over the period 1987-1994 on the intercept and the slope of one or more of three common sexually transmitted diseases: gonorrhea, chancroid, and syphilis. When the parameters of two sexually transmitted diseases were used as predictor variables, the adjusted multiple correlation coefficient (Radj) ranged from 0.70 to 0.77. When the parameters of all three sexually transmitted diseases studied were used in the regression model, the Radj reached a high value of 0.79. We conclude that incidence data of three common sexually transmitted diseases during an 8-year period presage the evolution of the AIDS epidemic during the subsequent 8-year period.