Three hundred and fifty-five prostitutes working in The Gambia were enrolled in a study of retroviral infections. Eight-seven (24.6%) were infected with HIV-2 only, two (0.6%) with HIV-1 only, four (1.1%) had sera showing double HIV-1/HIV-2 reactivity, and 37 (10.4%) were seropositive for HTLV-I. After allowing for socioeconomic and serological variables in a multivariate analysis, HIV-2 infection was associated with serological evidence of a previous episode of syphilis [a rapid plasma reagin (RPR) positive/Treponema pallidum haemagglutination assay (TPHA) positive; odds ratio (OR) = 2.18, 95% confidence interval (CI) = 1.19-3.98], with having antibodies against Haemophilus ducreyi (OR = 2.05, 95% CI = 0.89-4.70) or against HTLV-I (OR = 2.17, 95% CI = 0.91-5.19). HIV-2-seropositive prostitutes were three times more likely [17 out of 78 (22%) versus 15 out of 219 (7%), P less than 0.001] to have generalized lymphadenopathy than those who were seronegative. These data suggest that genital ulcer diseases may facilitate the transmission of HIV-2, and that HIV-2 rapidly induces the appearance of generalized lymphadenopathy in a substantial proportion of infected individuals.