Rates of Repeat Testing Among Patients Diagnosed with Chlamydia and Gonorrhea at a Public STD Clinic: San Francisco 2005-2006

Background:
Repeat testing is recommended for chlamydia and gonorrhea due to high rates of reinfection, but is challenging in asymptomatic STD clinic patients.

Objective:
To measure repeat testing among patients with CT and GC at the SF STD clinic from 2005-2006.

Method:
Chlamydia (CT) and gonorrhea (GC) cases were diagnosed using nucleic acid amplification tests (NAAT). Only the initial infection with each was included. Self-reported sexual orientation included: men who have sex with men or transgender (MSM/TG), men who have sex with women (MSW), Women, and Other. We limited return clinic visits to within 90-180 days of diagnosis; presence of symptoms was noted. Repeat testing was assessed at the first visit in the return period. The chi-square test was used for comparisons between groups.

Result:
From 2005-06, 52% (993/1895) of positive chlamydia tests were in MSM/TG, 19% (352/1895) in women and 29% (550/1895) in MSW. Overall, 21% of patients returned, but MSW were least likely (p<0.001). Retesting occurred in 17% of cases, higher among women (18%) and MSM/TG (18%) vs. MSW (14%) (p=0.019). Of those returning, 43% reported symptoms. Both symptomatic and asymptomatic had similar positivity: 16% vs. 13% (p=0.41). For GC, 75% (1452/1919) of positive results were in MSM/TG. Overall, 21% returned with women and MSM/TG more likely (p<0.001) and 16% retested, including 17% of MSM/TG, 24% of women and 9% of MSW (p<0.001). Of those returning, 53% reported symptoms. Symptomatic patients were more likely to test positive: 24% vs. 13% (p=0.022).

Conclusion:
Less than 25% of patients diagnosed with CT or GC returned as recommended for repeat testing. Higher rates in women and MSM may be due to increased counseling about retesting, or more frequent access to care. Retesting revealed disease, even in asymptomatic patients.

Implications:
STD clinics must continue to develop novel strategies to increase repeat testing in all patients with positive results.