HIV incidence among street youth in Montreal, Canada.

OBJECTIVES: To estimate HIV incidence and identify predictors of seroconversion among Montreal street youth. METHODS: From 1995 to 2000, street youth aged 14-25 years were recruited in a prospective cohort study. Interviews were conducted semiannually and included anti-HIV antibody testing. Among subjects who tested HIV negative at study entry and were interviewed at least twice, predictors of HIV seroconversion were identified using Cox regression. Variables considered as potential predictors were age, sex, injection drug use, being a male reporting male sexual partners, and survival sex. RESULTS: Overall, 1013 youth were recruited in the study. HIV prevalence at study entry was 1.4% [95% confidence interval (CI) 0.8-2.4] and was stable over the 6 recruitment years. Among the 863 subjects selected for the incidence analysis, 66.7% were boys, 47.2% had ever injected drugs at study entry, and 25.7% had ever engaged in survival sex. The selected participants cumulated 2327 person-years of follow-up and 16 HIV seroconversions were observed, for an incidence rate of 0.69 per 100 person-years (95% CI 0.39-1.11). In univariate analysis, injection drug use [hazard ratio (HR), 7.0] and involvement in survival sex (HR, 4.0) were associated with HIV incidence. In the multivariate analysis, only injection drug use was retained. CONCLUSIONS: Among Montreal street youth, injection drug use was the strongest predictor of HIV seroconversion. Prevention of initiation into injection drug use must become a public health priority.

Connectivity of the turtle accessory optic system.

Recent whole-cell recordings show that there are multiple synaptic inputs to the accessory optic system of the pond turtle Pseudemys scripta elegans (the basal optic nucleus, BON), suggesting a complex role in visual processing. The BON outputs have now been investigated using transport of diI, rhodamine-conjugated and biotinylated dextrans. Although transport was primarily anterograde, contralateral retinal ganglion cells were labeled retrogradely, confirming that the injection site was a retinal target. Other retrogradely labeled neurons were found ipsilateral to the injection site, in the pretectum, the ventral tegmentum, the dorsal nucleus of the posterior commissure and the lateral habenular nucleus. However, other data indicate that the habenular cells were labeled by spread of the tracer from the BON to the adjacent fasciculus retroflexus and interpeduncular nucleus. Anterogradely labeled fibers projected from BON following three paths, a lateral bundle to the ipsilateral dorsal midbrain, an intermediate bundle to the ipsilateral pretectal area or the posterior commissure and a ventral fiber bundle to the tegmentum bilaterally. Some of these fibers projected caudally through the tegmentum and cerebellar peduncle to terminate just below the Purkinje cell layer of the cerebellar cortex. Fibers that coursed via the intermediate bundle to the posterior commissure were also seen reaching the contralateral pretectal area and the contralateral BON. Injections of the retrograde tracer Fluorogold were also made in the BON to confirm the reciprocal connectivity of both basal optic nuclei. The pathways revealed by these experiments indicate the existence of multiple afferent and efferent connections of the BON, supporting the view that the accessory optic system is more than a simple relay of retinal signals into the brainstem for optokinetic reflexes.

HIV risk profile and prostitution among female street youths.

The objective of this study was to compare human immunodeficiency virus (HIV) risk factors among female street youths involved in prostitution and those with no history of prostitution. Youths aged 14 to 25 years were recruited into the Montreal Street Youth Cohort. Semiannually, youths completed an interviewer-administered questionnaire. Statistical analyses comparing characteristics and HIV risk factors for girls involved in prostitution and those never involved were carried out using parametric and nonparametric methods. Of the girls, 88 (27%) reported involvement in prostitution, and 177 girls reported no history of prostitution at the baseline interview. Girls involved in prostitution were two times and five times more likely to have reported bingeing on alcohol and on drugs, respectively. A history of injection drug use was four times more likely to have been reported by girls involved in prostitution. Further, these girls were 2.5 times more likely to have reported injected cocaine as their drug of choice. Girls involved in prostitution were younger the first time they had consensual sex and were twice as likely to have reported anal sex. Consistent condom use for anal, vaginal, and oral sex was low for all girls. Girls involved in prostitution reported more risky sexual partners. In conclusion, girls involved in prostitution may be at increased risk of HIV infection due to their injection drug use and risky sexual behaviors. Unique intervention strategies are necessary for reducing HIV infection among female street youths involved in prostitution.

Predictors of initiation into prostitution among female street youths.

Prostitution among female street youths represents an important risk factor for several health problems. Little is known about the incidence and determinants of prostitution in this vulnerable population, and no data have been previously reported based on a longitudinal follow-up study. The objective of this study was to determine predictors of initiation into prostitution among female street youths. Female youths aged 14 to 25 years were enrolled in the Montreal Street Youth Cohort. They completed a baseline and at least one follow-up questionnaire between January 1995 and March 2000. Girls who reported never having engaged in prostitution at baseline were followed prospectively to estimate the incidence and predictors of prostitution. Of the 330 female street youths enrolled as of September 2000 in the cohort, 148 reported no history of involvement in prostitution at baseline and completed at least one follow-up questionnaire. Of these 148 girls, 33 became involved in prostitution over the course of the study (mean follow-up 2.4 years), resulting in an incidence rate of 11.1/100 person-years. Multivariate Cox regression analysis revealed having a female sex partner (adjusted hazard ratio [AHR] 3.8; 95% confidence interval [CI] 1.6-9.1) was an independent predictor of initiation into prostitution after controlling for having been on the street at age 15 years or younger (AHR 1.8, 95% CI 0.9-3.8), using acid or phencyclidine (PCP; AHR 2.0, 95% CI 0.9-4.6), using heroin (AHR 1.9, 95% CI 0.7-5.5), the use of drugs greater than twice per week (AHR 1.9, 95% CI 0.9-4.2), and injection drug use (AHR 0.8, 95% CI 0.3-2.4). The incidence of prostitution in female street youths was elevated. Having a female sex partner was a strong predictor of initiating involvement in prostitution.

Sexual risk profile of young men in Vancouver, British Columbia, who have sex with men and inject drugs.

We compared sexual risk behaviors of men who have sex with men and inject drugs (MSM/IDU) with those of other men who have sex with men (MSM). Of 910 MSM surveyed, 106 (12%) injected drugs in the previous year. MSM/IDU were younger than MSM and more likely to be HIV-seropositive, Aboriginal, economically disadvantaged, engaged in the trade of sex for money or drugs, and to report having female sexual partners. MSM/IDU reported more casual sexual partners and in multivariate analyses were twice as likely to report unprotected receptive anal intercourse with casual partners. These results, combined with those from previous analyses, suggest that the higher risk for HIV seroconversion among MSM/IDU in this cohort is attributable mainly to sexual rather than injection-related exposures. Controlled assessments are needed to identify optimal sexual risk reduction strategies for MSM/IDU.