Sexually Transmitted Infection Risk Among Young Adult Non-Injecting Crack/Cocaine Users, Injecting Crack/Cocaine Users, and Injection Drug Users Who do not Use Crack/Cocaine in the United States

BACKGROUND: Crack/cocaine use is strongly and consistently associated with sexual risk. Emerging evidence also suggests that injection drug users face risk of STI and sexual, as well as parenteral, HIV transmission. We used Wave III (2001-2002) of the National Longitudinal Study of Adolescent Health (N=14,322) to assess drug use type and sexual risk among young adults in the US. METHODS: Wave III participants who reported crack/cocaine use and/or injection drug use (IDU) since Wave I (1995) were considered adult users of these drugs. We compared sexual risk among adults who reported crack/cocaine and IDU (injecting crack/cocaine users); crack/cocaine but no IDU (non-injecting crack/cocaine users); IDU but no crack/cocaine (injectors who did not use crack/cocaine); and non-users (the referent). RESULTS: Having four or more partners in the past year was associated with being a non-injecting crack/cocaine user (odds ratio (OR): 2.6, 95% confidence interval (CI): 2.2-3.1) and an injecting crack/cocaine user (OR: 2.2, 95% CI: 1.2-3.9) but not with being an injector who did not use crack/cocaine. Odds of sex with an infected partner in the past year were twice as high among injectors (regardless of crack/cocaine history) versus non-users and were somewhat elevated among non-injecting crack/cocaine users. STI was not associated with crack/cocaine use (regardless of IDU history) but was disproportionately high among injectors who did not use crack/cocaine (OR: 3.1, 95% CI: 1.2-8.1). CONCLUSIONS: Intensified STI/HIV testing and treatment and programs that educate about the risks of sexual transmission of disease are needed among both crack/cocaine users and injectors.