[The impact of HIV infection on the incidence of syphilis and gonorrhea at a university hospital (1985-1994)]

28876 new patients attending the sexually transmitted disease (STD) clinic of a university hospital in Buenos Aires between 1985 and 1994 were evaluated for the presence of syphilis and gonorrhea. This study assesses variations in incidence of the two diseases that may have resulted from behavioral changes occasioned by the rise of AIDS in the same years. 84% of the patients were male; 16% were female. Diagnostic tests included screening for Neisseria gonorrhoeae and penicillinase producers screening for Treponema pallidum by dark-field microscopy and serological analyses for syphilis. The percentage of cases positive for N. gonorrhoeae fluctuated around an average value of 14.8% from 1985 to 1991 but declined significantly to an average value of 4.0% during 1992-94. Penicillinase producers increased from 8.7% in 1985 to 44.6% in 1988 and later decreased slowly to 26.9% in 1994. The average proportion of dark-field examinations that were positive declined significantly from 20.7% during 1985-90 to 12.2% during 1991-94. The average proportion of positive serological analyses for syphilis declined from 45.7% during 1985-88 to 34.3% during 1989-94. The annual number of laboratory tests for all three conditions declined markedly during 1985-94 reflecting a greatly decreased attendance at the STD clinic. The proportion of declared homosexuals among new patients declined from 52% in 1988 to 28% in 1992. The declines may have resulted in part from AIDS prevention programs.