Latent classes of heroin and cocaine users predict unique HIV/HCV risk factors.
BACKGROUND
Patterns of heroin and cocaine use vary and may be associated with unique risk factors for bloodborne infections.


METHODS
Latent class analysis identified sub-populations of 552 heroin and cocaine users in Baltimore, Maryland. Using latent class regression, these classes were analyzed for associations with demographic characteristics, risky behaviors, Hepatitis C, and HIV.


RESULTS
Three classes were found: Crack/Nasal-Heroin users (43.5%), Polysubstance users (34.8%), and Heroin Injectors (21.8%). Compared to Polysubstance users, Crack/Nasal-Heroin users were almost 7 times more likely to identify as Black (OR=6.97, 95% CI=4.35-11.2). Sharing needles was over 2.5 times more likely among Polysubstance users than among Heroin Injectors (OR=2.66, 95% CI=1.49-4.75). Crack/Nasal-Heroin users were 2.5 times more likely than Polysubstance users to exchange drugs for sex (OR=2.50, 95% CI=1.22-5.13). Crack/Nasal-Heroin users were less likely than Heroin Injectors to have Hepatitis C (OR=0.10, 95% CI=0.06-0.18), but no significant differences were found for HIV.


CONCLUSIONS
Subpopulations of cocaine and heroin users differed in demographic classifications, HIV-risk behaviors, and Hepatitis C infection. All subpopulations included substantial numbers of HIV-positive individuals. Findings provide further evidence that non-injection drug users face significant infectious disease risk.
Johns Hopkins Bloomberg School of Public Health, Department of Mental Health, Baltimore, MD 21205, United States. pharrell@jhsph.edu
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Harrell
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Mancha
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Petras
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Trenz
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Latimer
D000328:Adult; D019970:Cocaine-Related Disorders / Q000145:classification / Q000453:epidemiology* / Q000821:virology; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000145:classification / Q000453:epidemiology*; D006526:Hepatitis C / Q000145:classification / Q000453:epidemiology*; D006556:Heroin Dependence / Q000145:classification / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D008297:Male; D016485:Needle Sharing / Q000009:adverse effects / Q000639:trends; D011237:Predictive Value of Tests; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior / Q000145:classification