Two quick estimates of the HIV prevalence in homosexual men in Los Angeles, New York and San Francisco. The Multicenter AIDS Cohort Study.

Two rough methods are given to estimate the combined HIV prevalence in Los Angeles, New York and San Francisco in homosexual men. Both methods are related to the back calculation technique, and use AIDS surveillance data and information obtained from the Multicenter AIDS Cohort Study. Both methods suggest that the combined HIV prevalence is approximately 100,000, with a possible range of 80,000-140,000.