HIV seroprevalence in sexually transmitted disease clients in a low-prevalence southern state. Evidence of endemic sexual transmission.

We studied human immunodeficiency virus (HIV) seroprevalence and risk factors in 3052 clients attending three large public, sexually transmitted disease (STD) clinics in central North Carolina in mid-1988. Anonymous self-administered questionnaires linked to HIV serologies obtained by testing extra blood from syphilis serologies without personal identifiers showed the following characteristics of the respondents: 60% were men, 81% were black, the median age was 24 years, 5% were injecting drug users since 1978, 7% reported a history of syphilis, and 8% of men were homosexual or bisexual. HIV seropositivity was found in 76 subjects (2.5%), including 46% of the homosexual men, 25% of the bisexual men, 1.6% of the heterosexual men, and 0.6% of the women. Elevated HIV seroprevalence rates were found in subjects with a history of or seroreactivity for syphilis (HIV-positive rate of 53% in homosexual or bisexual men, 9% in heterosexual men, 3% in women) and with histories of gonorrhea (HIV-positive rate of 37% in homosexual or bisexual men, 2.6% in heterosexual men, 1% in women), and intercourse (41% in homosexual or bisexual men, 2% in women), prostitute contact (5% in heterosexual men), and sex with casual partners (2% in women). Even a state with a low incidence of acquired immunodeficiency syndrome can include subpopulations with a high HIV seroprevalence, apparently disseminated endemically in association with bacterial STDs.