Is jail screening associated with a decrease in Chlamydia positivity among females seeking health services at community clinics?-San francisco, 1997-2004.

BACKGROUND Young adults entering jail are at increased risk for sexually transmitted diseases (STD) such as chlamydia, are released quickly, and are unlikely to be tested for STDs elsewhere. San Francisco jails performed targeted chlamydia screening and treatment since 1996. GOAL To determine this program's impact on chlamydia positivity among females attending neighborhood medical clinics. STUDY DESIGN During 1997-2004, jail testing density, a measure of the proportion of persons from year 2000 census blocks that were tested in jail, was compared by neighborhood. Chlamydia positivity among females aged 15 to 25 years were compared at 2 clinics serving areas with different jail testing densities. RESULTS Of persons offered screening at intake, 89% accepted. A total of 42,952 tests were performed among 23,561 persons in jail (45% black, 73% male). A total of 2765 (6.4%) tests were positive for chlamydia; 81% of chlamydial infections were treated. Jail testing density significantly correlated with neighborhood female chlamydia rates. Mean jail testing density at Clinic S, calculated by using the residence of persons tested for chlamydia, was 7 times greater than that at Clinic O. Chlamydia positivity declined at Clinic S from 16.1% to 7.8% (Ptrend <0.001). No significant change occurred at Clinic O in chlamydia (4.7% in 1997 and 2004, Ptrend = 0.81). CONCLUSIONS In San Francisco, screening young adults in jail focused testing on persons from neighborhoods with high chlamydia rates. Jail screening started immediately before chlamydia declines among young females at a clinic serving neighborhoods with high jail testing density. These programs might help reduce community prevalence and racial/ethnic disparities in STDs.