Incidence and Predictors of HIV and Sexually Transmitted Infections Among Female Sex Workers and Their Intimate Male Partners in Northern Mexico: A Longitudinal, Multilevel Study

Abstract

Preventing human immunodeficiency virus (HIV) infection and other sexually transmitted infections (STIs) requires an understanding of sexual relationship factors beyond the individual level. We estimated HIV/STI incidence and identified time-varying predictors of STI acquisition in a prospective cohort study of female sex workers and their intimate (noncommercial) male partners in northern Mexico. From 2010 to 2013, couples underwent behavioral and biological assessments biannually for 24 months. Among 413 initially HIV-uninfected participants, 8 seroconverted during follow-up. Incidence of HIV (1.12 cases/100 person-years (PY)), chlamydia (9.47 cases/100 PY), active syphilis (4.01 cases/100 PY), and gonorrhea (1.78 cases/100 PY) was higher among women than among men (HIV: P = 0.069; all STIs combined: P < 0.001). In multivariable conditional logistic regression with individual fixed effects and correlated error terms within couples, risk of STI acquisition was significantly higher among women who had recently used cocaine, crack, or methamphetamine (adjusted odds ratio (OR) = 2.13, 95% confidence interval (CI): 1.07, 4.28). STI risk was lower among women who reported physically assaulting their male partners (adjusted OR = 0.44, 95% CI: 0.22, 0.86) and among men whose female partners had regular sex-work clients (adjusted OR = 0.38, 95% CI: 0.14, 1.03). Improving vulnerable couples' sexual health will require addressing the contexts in which drug use, interpersonal conflict, and economic vulnerability converge.

The role of dyad-level factors in shaping sexual and drug-related HIV/STI risks among sex workers with intimate partners

“…A recent quantitative study demonstrates that feelings of love and trust are significantly associated with sexual risk and drug use patterns among SWs and their intimate partners (Syvertsen et al, 2015). Thus, the intersection of feelings of love/intimacy/trust, drug use, financial dependence, and IPV considerably influences, and is influenced by, unprotected sex among SWs and their intimate partners (Robertson Bazzi et al, 2015; Syvertsen et al, 2015; Ulibarri et al, 2015). Among drug-using women in the U.S., inconsistent condom use and requesting partners to use condoms were significantly associated with IPV (El-Bassel et al, 2005).…”

“…In a prospective randomized control trial with low-income drug users, a couples-based intervention that focused on both sexual and drug risks successfully reduced the incidence rate (by 30%) of unprotected sex acts between partners over follow-up (El-Bassel et al, 2011). Actively involving male partners in HIV prevention programs may help to support SWs’ empowerment and facilitate communication and negotiation skills between partners around sexual and drug use-related risks (Robertson Bazzi et al, 2015). Future research that seeks to include male intimate partners should ensure that couples-based interventions are situated within a context of offering services tailored to the unique needs of both SWs and their intimate partners, free of discrimination, and where service providers can build trust with their patients and improve consistency of care (El-Bassel et al, 2011; Palinkas et al, 2014).…”

“…Future research that seeks to include male intimate partners should ensure that couples-based interventions are situated within a context of offering services tailored to the unique needs of both SWs and their intimate partners, free of discrimination, and where service providers can build trust with their patients and improve consistency of care (El-Bassel et al, 2011; Palinkas et al, 2014). Couples-based interventions that focus on reducing conflict and improving communication between partners will be especially important for future HIV prevention efforts (Robertson Bazzi et al, 2015). Taken together with our study’s findings, couples-based and gender-focused interventions that include male partners are needed to reduce potential HIV/STI risks to SWs through nonpaying partnerships, including discussions of the complex pathways of intimacy, trust, and power in shaping condom use dynamics within intimate partner dyads.…”

Changes in Condom Use Over Time Among Female Sex Workers and Their Male Noncommercial Partners and Clients

“…Participants with confirmed HIV infection were referred to public clinics for free medical care and treatment. Participants who tested positive for other STIs received free treatment based on U.S. and Mexican guidelines (see Bazzi et al, 2015 for HIV/STI testing procedures and results). Participants received $20 for the completion of each interview.…”

“…However, these effects did not extend to FSWs and their main, noncommercial male partners (e.g., spouses and boyfriends; Ulibarri et al, 2012), which lead to longitudinal research on the social epidemiology of HIV/STIs among FSWs and their intimate male partners in these cities. During this observational research, which was conducted over a 24-month follow-up period, Bazzi et al (2015) documented HIV incidence among these couples to be 1.12 per 100 person years (py), and combined STI incidence (excluding HIV) to be 15.2 per 100 py. A total of 145 new STI infections were detected over the course of the study, and 8 out of 413 initially HIV-negative participants seroconverted.…”