Substance use and engagement across the HIV care continuum among female sex workers, a key population in Malawi

The effect of substance use on optimal engagement across the HIV care continuum must be delineated to inform strategies that enhance HIV testing and treatment for female sex workers (FSW), a key population in sub-Saharan Africa for HIV transmission. We characterize the HIV care continuum and evaluate the association between substance use with engagement in HIV testing and treatment among FSW in Lilongwe, Malawi. From July through September 2014, we enrolled 200 FSW ≥18 years using venue-based sampling into a cross-sectional evaluation to assess engagement in the HIV care continuum and substance use. Seropositive FSW, identified using HIV rapid testing, received rapid CD4 counts and viral loads using dried blood spots. We examined the associations of alcohol and marijuana use with lack of HIV infection awareness and sub-optimal HIV treatment outcomes: lack of ART use among ART-eligible and viral nonsuppression. FSW had a very high HIV seroprevalence of 69%. Sixty-nine percent of HIV-infected FSW had a history of HIV care, 52% reported current ART use, and 45% were virally suppressed. Among HIV-infected FSW, 45% were non-hazardous drinkers, 28% were hazardous drinkers, 12% were harmful drinkers, and 15% were alcohol dependent. We observed a dose-response relationship between increased alcohol use and lack of HIV infection awareness. The prevalence ratio for lack of HIV infection awareness in multivariable analysis was 1.14 (95% CI: 0.53, 2.45) among current marijuana users. In multivariable analysis, FSW who were harmful drinkers or alcohol dependent were 1.9 (95% CI: 1.0, 3.8) times as likely to not use ART. The bivariable prevalence ratio for FSW nonsuppressed was 2.0 (95% CI: 0.6, 6.5) among harmful drinkers and alcohol dependent FSW. In multivariable analysis, FSW who were currently using marijuana were 1.9 (95% CI: 0.8, 4.6) times as likely to not use ART. Alcohol use is an influential barrier to achieving optimal HIV testing and treatment outcomes, which are necessary to receive the clinical, immunological, and transmission benefits of therapy. Prioritizing combination interventions to incorporate alcohol risk reduction strategies, in addition to other substances, will improve the uptake of HIV testing and treatment for HIV-infected FSW in Malawi.Doctor of Philosoph