Potential impact of chemical prophylaxis on the incidence of gonorrhoea.

This paper presents a stochastic statistical model to evaluate the potential impact on the incidence of gonorrhea of a prophylactic intravaginal compound. The model predicts the change in the national incidence of gonorrhea in the US at various hypothetical levels of effectiveness of the topical prophylactic and of population usage. Factors analyzed in calculating the expected number of cases of gonorrhea under different conditions included the average risk of an uninfected person acquiring gonorrhea during a generation (incubation + average time to next sex act) the overall rate of loss of infectiousness whether by treatment or spontaneous cure during a generation the proportion of at risk individuals prevented from acquiring a gonococcal infection in a generation by a prophylactic compound and the proportion of the population at risk using the compound before each act of coitus. This model indicates that with no changes in venereal disease prevention and treatment programs the number of cases of gonorrhea will increase by 17% from 577486 in 1970 to 674804 in 1971. However if only 30% of the population at risk used a prophylactic product that is 70% effective gonorrhea could be almost completely eliminated within 5 years. Even a 50% effective prohylactic used by only 25% of the at risk population could produce dramatic decreases in the incidence of gonorrhea in a short time. Prophylactic programs will be most effective if incorporated into existing treatment and education programs. (summary in FRE)