Identifying the HIV transmission bridge: which men are having unsafe sex with female sex workers and with their own wives or steady partners?

OBJECTIVE: To gain insights into bridging behaviors and their correlates among male clients of female sex workers (FSWs).
METHODS: Men aged ≥18 years who recently paid or traded for sex with FSWs were recruited in Tijuana in 2008-2009. Participants underwent interviews and testing for HIV, chlamydia, syphilis, and gonorrhea. Logistic regression compared "bridgers" (clients who had unprotected sex with FSWs and with a wife or steady partner) with men who did not.
RESULTS: Of 383 men, 134 (35%) had a steady partner. Half (n = 70) of those had unprotected sex with both FSWs and the steady partner. Prevalence of any sexually transmitted infection or HIV was 16.5% among bridgers and 2.3% among nonbridgers. Compared with other clients, bridgers were more likely to use drugs during sex with FSWs (81.4% versus 46.9%, P < 0.0001), had higher sensation-seeking (P < 0.0001) and misogyny scores (P = 0.05) and were more likely to offer FSWs extra money for unprotected sex (34.4% versus 1.6%, P < 0.0001). Factors independently associated with bridging were as follows: using drugs during sex with FSWs [adjusted odds ratio (AOR): 3.4, P = 0.007], sensation seeking (AOR: 4.3 per unit increase, P = 0.05), and offering FSWs more money for unprotected sex (AOR: 24.5, P = 0.003).
CONCLUSION: Sensation-seeking clients who use drugs during sex and coerce FSWs into unprotected sex may be less responsive to standard risk reduction interventions. Interventions are needed that target clients rather than rely on FSWs to change behaviors that may not be under their control.