The findings and conclusions in these presentations have not been formally disseminated by the Centers for Disease Control and Prevention and should not be construed to represent any agency determination or policy.

Tuesday, May 9, 2006

Repeat chlamydia and gonorrhea infection using case-based surveillance reports and laboratory-based prevalence monitoring data, California, 2003-2004

Jm Chow1, J. Guo1, D. Gilson2, Michael C. Samuel2, S. Barbosa3, K. Sisco3, K. Mueller3, H. Thiel de Bocanegra4, S. Steinberg5, R. Baxter6, and G. Bolan7. (1) Sexually Transmitted Disease Control Branch, California Department of Health Services, 850 Marina Bay Parkway, Building P, Second Floor, Richmond, CA, USA, (2) STD Control Branch, California Department of Health Services, P.O. Box 997413, MS 7320, Sacramento, CA, USA, (3) Quest Diagnostics, Inc, 18408 Oxnard Street, Tarzana, CA, USA, (4) Bixby Center for Reproductive Health Research and Policy, University of CA, San Francisco, 1615 Capitol Ave, P.O. Box 997413, MS 8400, Sacramento, CA, USA, (5) Maternal, Child, Adolescent Health/Office of Family Planning, California Department of Health Services, 1615 Capitol Avenue, MS 8300, P.O. Box 997420, Sacramento, CA, USA, (6) Internal Medicine, Kaiser Permanente Medical Program, 280 W. MacArthur Blvd, Oakland, CA, USA, (7) STD Control Branch, CA Department of Health Services, 850 Marina Bay Parkway, Bldg. P, 2nd Floor, Richmond, CA, USA

Rates of repeat chlamydia (CT) and gonorrhea (GC) infections are an indirect measure of partner service program performance. Individuals with repeat infections are a priority population for CT/GC prevention interventions. Re-testing and repeat infection vary across populations.

Estimate repeat female CT/GC infection using case-based and prevalence monitoring data.

During 2003-2004, CT/GC cases reported to California State surveillance, CT/GC test result data from a commercial laboratory in the California Family Planning, Access, Care, Treatment (FP) program, and a large health maintenance organization were used to estimate repeat infection 1-6 months after initial case report or positive test result. Case-based repeat infections were identified using name/birthdate/county-based matching.

There were 56,891 CT and 8,748 GC unique female case reports in 2004. Six percent of CT cases and 4% of GC cases had a repeat case report within 1-6 months. There were 133,794 CT tests (3.6% positive) and 101,278 GC tests (0.36% positive) available among 134,312 FP females. There were 198,582 CT tests (2.4% positive) and 196,479 GC tests available (0.35% positive) among 201,794 HMO females. One-quarter of FP CT/GC-positives and 40% of HMO CT/GC-positives were re-tested within 1-6 months. Eleven percent of FP CT-positives and 10.4% of HMO CT-positives were repeat CT-positive; 7.3% of FP GC-positives and 7.6% of HMO GC-positives were repeat GC-positive. Repeat infection among adolescent females was 8.5% for CT cases, 15.2% for FP female CT-positives and 15.1% for HMO female CT-positives; 5.4% for GC cases, 12.8% for FP GC-positives, and 8.1% for HMO GC-positives.

Repeat CT/GC rates are consistently high and suggest that case-based reporting systems can be used to identify repeat infections if prevalence monitoring data are not available.

Targeted CT/GC re-testing recommendations for females are warranted to identify infections and prevent further transmission. These data support recommendations to re-test CT/GC patients by 6 months after initial infection.