377 female prostitutes were selected from bars hotels and nightclubs throughout Kinshasa Zaire and enrolled in an LAV/HTLV-III seroprevalence study. Participants ranged in age from 14-50 years old had been prostitutes for a mean of 3.2 years and reported means of 3.7 sexual partners during the previous week 158 during the previous year and 703 lifetime sexual partners. 101 (27%) of 377 prostitutes were repeatedly LAV/HTLV-III seropositive by ELISA technique (Western blot examinations pending). Seropositivity was significantly associated with the number of lifetime sexual partners (median 600 partners for seropositives vs 338 for seronegatives (Wilcoxon Rank Sum test p=0.02) taking of oral medications for prevention of sexually transmitted diseases or other purposes (85/280 seropositive vs 16/97; odds ratio=2.21 95% confidence interval 1.2-4.2) and introduction of any product into the vagina (including internal menstrual hygiene douching vaginal lubrification products for vaginal cleaning or other purposes) (89/300 seropositive vs 12/77; odds ratio=2.3 95% confidence interval 1.1-4.7). In addition among 85 prostitutes reporting condom use by their sexual partners during the previous year use of condoms by 50% or more of their partners was associated with a reduced risk of being LAV/HTLV-III seropositive (0/8 vs 26/77; Fishers exact test p=0.046). LAV/HTLV-III seropositivity was not associated with reported participation in fellatio or anal intercourse nor with any quantitative measure or type of kissing behavior. 29% of prostitutes reported at least 1 symptom suggestive of LAV/HTLV-III infection and seropositivity was associated with weight loss alone or in association with chronic diarrhea or pruritic dermatitis. Study data suggest that factors interfering with the integrity of vaginal or cervical mucosa may be associated with an increased risk of LAV/HTLV-III infection acquired through heterosexual contact. (full text)