Background:
Few data are available describing prevalence of STD, including CT, among women who report sex with women in the U.S.

Objective:
The Region X Infertility Prevention Project (IPP) provides screening for CT and treatment to women at 150 family planning, STD and other clinics in the Northwest. We describe prevalence of and risks associated with CT infection among WSW and WSMW attending these clinics between 1997-2005.

Method:
Inclusion criteria included female sex and report of sex with a woman on a routine data collection form. CT positivity was calculated by patient demographics, other behavioral risks, and clinical findings for tests among women aged 15-24 years seen at 132 IPP clinics. Multivariate models were used to assess differences and temporal trends.

Result:
9,510 tests associated with report of sex with a woman were identified. 5,801 (61%) reported sex exclusively with women, and 3,709 (39%) sex with men also. CT positivity was 7.1% for both groups. 44% of tests were from women aged 15-19 years and 76% from non-Hispanic (NH) Whites. In the 60 days before testing, 36% reported new partner (SP), 25% multiple SPs, and 7% symptomatic SP. Significant (P<0.05) risks for CT included age < 20 years (OR=1.44) non-White race/ethnicity (OR=1.47); new SP (OR=1.50); symptomatic SP (OR=1.89); symptoms as reason for visit (OR=1.34); exposure to CT (OR=5.32) and clinical findings (OR=2.51). CT trend was stable over time. In comparison, CT positivity for women reporting sex only with men during the study period was 5.3%.

Conclusion:
Report of same sex behavior in women attending IPP clinics should not deter providers from performing CT screening if otherwise indicated by current screening guidelines.

Implications:
Further research is needed to identify what specific risks predispose to acquisition and transmission of CT in this group, and to characterize sexual networks of sexual minority women.