Syphilis, human immunodeficiency virus infection, and targeting prevention.

To examine the interaction between syphilis and human immunodeficiency virus-type 1 (HIV-1) infection in Oklahoma, we conducted an unlinked HIV seroprevalence survey using serum specimens submitted to the Oklahoma State Department of Health for serologic test for syphilis. Of specimens with positive results from fluorescent treponemal antibody absorption test (FTA-ABS), 6.3% were HIV-1 seropositive compared to 0.8% of those that had negative results from FTA-ABS. Among specimens positive for syphilis, HIV-1 seropositivity was found almost exclusively among those from persons 20 to 39 years of age and more often among those from men than those from women (9.9% vs 1.3%). Of syphilis-positive specimens from 20- to 39-year-old men, 17.6% were HIV-1 seropositive. In Oklahoma, an area with a relatively low overall prevalence of HIV-1 infection, targeting prevention efforts to young adults who test positive for syphilis should be an efficient way to reach some persons at high risk for HIV-1 infection.