Its a syphilis epidemic, so say officials with public health in San Francisco.

Among gay men in San Francisco, syphilis increased by 25% in 2010 vs last year.  It has reached an all time high in the city.

The facts point to the outbreak being predominantly in gay males, not in women or in heterosexual men.

See Syphilis cases hit all-time high | Andrea Koskey | Local | San Francisco Examiner.