Individual and poly-substance use and condomless sex among HIV-uninfected adults reporting heterosexual sex in a multi-site cohort

BACKGROUND

We analyzed the association between substance use (SU) and condomless sex (CS) among HIV-negative adults reporting heterosexual sex in the Seek, Test, Treat, and Retain (STTR) consortium. We describe the impact of SU as well as person/partner and context-related factors on CS, identifying combinations of factors that indicate the highest likelihood of CS.

METHODS

We analyzed data from four US-based STTR studies to examine the effect of SU on CS using two SU exposures: 1) recent SU (within 3 months) and 2) SU before/during sex. Behavioral data were collected via 1:1 or self-administered computerized interviews. Adjusted individual-study, multivariable relative risk regression was used to examine the relationship between CS and SU. We also examined interactions with type of sex and partner HIV status. Pooled effect estimates were calculated using traditional fixed-effects meta-analysis. We analyzed data for recent SU (n = 6781; 82% men, median age = 33 years) and SU before/during sex (n = 2915; 69% men, median age = 40 years).

RESULTS

For both exposure classifications, any SU other than cannabis increased the likelihood of CS relative to non-SU (8-16%, p-values< 0.001). In the recent SU group, however, polysubstance use did not increase the likelihood of CS compared to single-substance use. Cannabis use did not increase the likelihood of CS, regardless of frequency of use. Type of sex was associated with CS; those reporting vaginal and anal sex had a higher likelihood of CS compared to vaginal sex only for both exposure classifications (18-21%, p < 0.001). Recent SU increased likelihood of CS among those reporting vaginal sex only (9-10%, p < 0.001); results were similar for those reporting vaginal and anal sex (5-8%, p < 0.01). SU before/during sex increased the likelihood of CS among those reporting vaginal sex only (20%; p < 0.001) and among those reporting vaginal and anal sex (7%; p = 0.002). Single- and poly-SU before/during sex increased the likelihood of CS for those with exclusively HIV-negative partners (7-8%, p ≤ 0.02), and for those reporting HIV-negative and HIV-status unknown partners (9-13%, p ≤ 0.03).

CONCLUSION

Except for cannabis, any SU increased the likelihood of CS. CS was associated with having perceived HIV-negative partners and with having had both anal/vaginal sex.

Injection-related risk behaviors in young urban and suburban injection drug users in Chicago (1997-1999)

We compared injection-related risk practices between urban and suburban injection drug users (IDUs) in a large cross-sectional sample of young IDUs. From 1997 to 1999, we recruited 700 active IDUs aged 18 to 30 years in Chicago and its suburbs. A suburban residence was reported by 38% of participants. Participants were interviewed at four urban locations and screened for HIV and hepatitis C virus antibodies. Receptive sharing of syringes and other paraphernalia by urban and suburban IDUs in the preceding 6 months was compared using univariable and multivariable models. Sharing injection paraphernalia in the total sample was high, with 50% of participants reporting receptive syringe sharing and 70% reporting sharing cotton, cookers, and/or rinse water. After adjusting for demographic characteristics, injection settings, frequency, and duration of injection as well as ease of acquiring new syringes, suburban IDUs were significantly more likely than urban IDUs to share syringes (adjusted odds ratio = 1.7; 95% confidence interval: 1.1-2.5); however, the likelihood of sharing cotton, cookers, or rinse water was roughly equal. Despite overall higher risk profiles among suburban IDUs, HIV and hepatitis C prevalence levels were significantly lower than among urban participants. Current high levels of injection risk behaviors in suburban groups represent a potential for rapid dissemination of infection.

Prevalence and incidence of HIV among out-of-treatment injecting drug users, Chicago 1994-1996

OBJECTIVES

To assess HIV prevalence, incidence, and associated risk factors among IDUs in Chicago.

METHODS

Seven hundred ninety-four street-recruited IDUs ranging in age from 18 to 50 years, who were not in drug treatment at study enrollment, were interviewed and tested for HIV at baseline and at two follow-ups scheduled 6 and 12 months after baseline. Questionnaires assessed respondents' demographic characteristics, medical and drug treatment histories, drug use, and sexual practices.

RESULTS

HIV seroprevalence at baseline was 18%. Logistic regression identified the following determinants of prevalent HIV infection: Puerto Rican ethnicity, homosexual or bisexual self-identification, injecting for 4 or more years, and having smoked crack cocaine in the past 6 months. Follow-up data were collected from 584 (73.6%) participants. Mean duration of follow-up was 16.5 months, indicating that most subjects had follow-up intervals longer than the scheduled 6 and 12 months. Seven HIV seroconversions were observed in 632 person years of risk, yielding an incidence rate of 1.1 per 100 person years of risk. Injection for 3 or less years was positively associated with HIV seroconversion.

CONCLUSIONS

The findings provide evidence of a decline in HIV incidence among IDUs, though newer injectors remain at elevated risk for infection.

Hepatitis C virus infection: prevalence, risk factors, and prevention opportunities among young injection drug users in Chicago, 1997-1999

The prevalence, risk factors, and prevention opportunities of hepatitis C virus (HCV) infection were studied in a large sample of 698 young adult injection drug users (IDUs) in Chicago, 18-30 years old. Participants were recruited between 1997 and 1999 by using street outreach, targeted advertising, and chain-referral methods. HCV infection prevalence was 27% and was strongly associated with both age and duration of injecting (P<.001). In multivariable analysis, sexual behaviors were unrelated to seropositivity. Independent drug-related risk factors included frequent injection, heavy crack smoking, injecting in a shooting gallery, and syringe-mediated sharing. Urban residents were more likely than suburban residents to be infected. Most research on hepatitis C has shown rapid spread of infection among IDUs, but these findings underscore that opportunities to identify IDUs uninfected with HCV may be greater than assumed and emphasize the need to target younger, newer IDUs.

Prevention of HIV infection in street-recruited injection drug users. The Collaborative Injection Drug User Study (CIDUS)

BACKGROUND

Injection drug users (IDUs) and their sex partners account for an increasing proportion of new AIDS and HIV cases in the United States, but public debate and policy regarding the effectiveness of various HIV prevention programs for them must cite data from other countries, from non-street-recruited IDUs already in treatment, or other programs, and from infection rates for pathogens other than HIV.

METHODS

Participants were recruited from the street at six sites (Baltimore [Maryland], New York [two sites], Chicago [Illinois], San Jose [California], Los Angeles [California], and at a state women's correctional facility [Connecticut]), interviewed with a standard questionnaire, and located and reinterviewed at one or more follow-up visits (mean, 7.8 months later). HIV serostatus and participation in various programs and behaviors that could reduce HIV infection risk were determined at each visit.

RESULTS

In all, 3773 participants were recruited from the street, and 2306 (61%) were located and interviewed subsequently. Of 3562 initial serum specimens, 520 (14.6%) were HIV-seropositive; at subsequent assessment, 19 people, all from the East Coast and Chicago, had acquired HIV. Not using previously used needles was substantially protective against HIV acquisition (relative risk [RR], 0.29; 95% confidence interval [CI], 0.11-0.80 ) and, in a multivariate model, was significantly associated with use of needle and syringe exchange programs (adjusted odds ratio [ORadj], 2.08; 95% CI, 1.15-3.85). Similarly, reduction of injection frequency was very protective against seroconversion (RR, 0.33; 95% CI, 0.14-0.80), and this behavior was strongly associated with participation in drug treatment programs (ORadj, 3.54; 95% CI, 2.50-5.00). In a separate analysis, only 37.5% of study-participants had sufficient new needles to meet their monthly demand.

CONCLUSIONS

In this large multicity study of IDUs in the United States, several HIV prevention strategies appeared to be individually and partially effective; these results indicate the continued need for, and substantial gaps in, effective approaches to preventing HIV infection in drug users.

The onset of drug injection among sex partners of injection drug users

HIV prevention interventions targeting noninjecting sex partners of drug injectors usually focus on sexual behaviors. This strategy may underestimate the likelihood that sex partners will begin injecting drug and thereby greatly increase their exposure to HIV. This 4-year prospective study assesses the incidence of drug injection among 62 street-recruited, heterosexual, HIV negative, baseline noninjection sex partners, 97% of whom were reinterviewed at least once. Sixteen (26%) of the sex partners reported injecting after baseline. Thirty-nine percent of those with no history of illicit drug use beyond marijuana began injecting, compared with 19% of those who had used drugs but had never injected and 11% of those with injection histories. There were two HIV seroconversions, both of which took place soon after the onset of injection and appear attributable to parenteral transmission. These results suggest that interventions targeting sex partners should include strategies for preventing injection and risky injection practices.

From bag brides to skeezers: a historical perspective on sex-for-drugs behavior

There are many ways that women support their use of crack cocaine, including sex-for-crack bartering and other forms of prostitution. Empirical studies conducted in the mid-1970s and in the mid-1980s in New York City, and in Chicago in the late 1980s to early 1990s are compared, analyzing similarities and differences between the contemporary crack-prostitution scene and previous prostitution scenes. Findings suggest that the arrival of crack cocaine has directly and indirectly affected the drugs-prostitution nexus by lowering the price of sex for street prostitutes, altering the social status of cocaine, and increasing the level of social disorganization in illicit street activities, including prostitution. Barterers are shown to be the heaviest drug users, using the greatest variety of drugs, using larger amounts of drugs, and using more frequently.