It is.
During the gold rush there was an outbreak of plague in San Francisco's Chinatown. A physician detected it and reported it to the city government, along with recomendations to contain it. The town fathers insisted that there was no plague in their fair city, refused to accept the report or institute a rat catching program.
Plague spread to the ground squirel population, escaped the city and is now endemic across the entire western US.
Any parallels one may wish to draw with a more recent "gay plague" are left to the reader as an exercise.
Those who do not remember the lessons of history are doomed to repete them...
That sounds like the SF of today.