With the early 1980’s came the recognition that AIDS was spread by casual sex. The CDC in 1981 retroactively identified patient zero of an epidemic begun in 1980 San Francisco.
It was quite a scandal because one public health measure was to close down the public "bath" houses which the politicians did not want to do. I forget how it finally happened. Of course DiFi was in the middle of this muddle as the Mayor, in the wake of the Harvy Milk assassination.