Fethers K, Marks C, Mindel A, Estcourt CS
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).
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).
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 homo/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.
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.