Syphilis in HTLV-III infected male homosexuals.

Out of 100 male homosexual persons screened for AIDS, 54 were found to be HTLV-III antibody positive. Of these, 34 (63%) had a positive history of syphilis, as compared to 16 (35%) of the 46 HTLV-III antibody negative persons (P less than 0.01). In the HTLV-III antibody positive group 12 (22%) had had more than three syphilis infections as compared to none in the negative group (P = 0.02). The frequency of a previous primary, secondary, and latent syphilitic infection was different in the two groups. During the 1970s and early 1980s the incidence of syphilis in the U.S.A. and in Denmark was increasing, but from 1982 the incidence decreased markedly, possibly a consequence of the fear of AIDS, which appeared in 1981-82. It is speculated that the high frequency of syphilis among homosexual men might have been a co-factor for the acquisition of the HTLV-III infection.