Background Canadian street-involved youth are at greater risk for sexually transmitted infections (STIs), due to their increased vulnerabilities related to age, socioeconomic status, life course factors, and engagement in high risk behaviour such as sex trade. We present a risk factor analysis for those with single and multiple STIs, using the Enhanced Surveillance of Canadian Street Youth (E-SYS) data.

Methods E-SYS is a cross-sectional surveillance system of street-involved youth (15–24 years). Participants from seven urban centres completed an interviewer-administered questionnaire and were tested for multiple sexually transmitted and blood-borne infections. For this analysis, data were restricted to five infections (HIV, chlamydia, gonorrhoea, syphilis and HSV-2). Data from three cycles (2001–2006) were analysed to determine total number of infections per participant using an iterative tracker. Participants who indicated previous participation were excluded from the analysis to avoid double-representation.

Results Of those who provided biological specimens (n=3823), 17.0% tested positive for one infection and 3.4% tested positive for two or more infections (Abstract O1-S04.03 table 1). Over half (15 of 28) of HIV-positive individuals were multiply-infected. Risk factors for multiple infections included older age (p=0.0449), being Aboriginal (p=0.0061; particularly females), being HIV infected (p=<0.0001), having a previous history of an STI (p=0.0144), pregnancy (p=0.0079), and reporting prostitution as the primary source of income (p=0.0028).

Conclusions The prevalence of certain STI co-infections (eg, chlamydia and gonorrhoea) is high among street-involved youth and within this population, certain sub-groups may be more vulnerable to these co-infections. Continued efforts are required to promote comprehensive STI testing among street-involved youth and to raise awareness of the potential for multiple infections.