Sexually transmitted infections and risk behaviours in women who have sex with women

Objectives: To assess the prevalence of sexually transmitted infections (STIs) and blood borne viruses, risk behaviours, and demographics in women who have sex with women (WSW). Methods: Retrospective cross sectional study using a multivariate model. Demographic, behavioural, and morbidity data were analysed from standardised medical records of patients attending a public STI and HIV service in Sydney between March 1991 and December 1998. All women with any history of sex with a woman were compared with women who denied ever having sex with another woman (controls). Results: 1408 WSW and 1423 controls were included in the study. Bacterial vaginosis (BV) was significantly more common among WSW (OR 1.7, p<0.001). Abnormalities on cervical cytology were equally prevalent in both groups, except for the higher cytological BV detection rate in WSW (OR 5.3, p=0.003). Genital herpes and genital warts were common in both groups, although warts were significantly less common in WSW (OR 0.7, p=0.001). Prevalence of gonorrhoea and chlamydia were low and there were no differences between the groups. The prevalence of hepatitis C was significantly greater in WSW (OR 7.7, p<0.001), consistent with the more frequent history of injecting drug use in this group (OR 8.0, p<0.001). WSW were more likely to report previous sexual contact with a home/bisexual man (OR 3.4:, p<0.001), or with an injecting drug user (OR 4.2, p<0.001). Only 7% of the WSW reported never having had sexual contact with a male. Conclusion: We demonstrated a higher prevalence of BV, hepatitis C, and HIV risk behaviours in WSW compared with controls. A similar prevalence of cervical cytology abnormalities was found in both groups. Measures are required to improve our understanding of STI/HIV transmission dynamics in WSW, to facilitate better health service provision and targeted education initiatives.