Results from a Pilot of Universal Extra-Genital Chlamydia and Gonorrhea Screening Among Men Who Have Sex with Men (MSM) Who Attend Los Angeles County STD Clinics

Background: In February 2015, the Los Angeles County (LAC) Department of Public Health piloted a universal chlamydia (CT)/Gonorrhea (GC) extra-genital screening protocol at 12 municipal STD clinics among all men who have sex with men (MSM) to determine if it resulted in increased morbidity.

Methods:  Medical records for MSM patients seen during the 6 months after protocol implementation (February-August, 2015; n=1637) and during the same 6 months of the previous year (February-August, 2014; n=1346) were compared for universal screening (defined as receipt of urogenital, oropharyngeal, and anorectal testing) and positive CT/GC laboratory test at any anatomic site.  The difference (pre vs. post) in the proportion of visits with universal screening was calculated for each clinic to measure improvement in screening practices as: high (>10 percentage point increase), medium (1-10 percentage point increase), or no improvement/decrease.  Multivariate logistic regression models were fit to the data and interaction terms compared CT/GC diagnoses during the pre- vs post-protocol period at high improvement vs. no improvement/decrease clinics and medium improvement vs. no improvement/decrease clinics.

Results: Overall, the proportion of visits with universal screening rose 6.5 percentage points (Pre: 60.6%, n=815; Post: 67.1%, n=1099; p<0.001) although there was substantial variation across clinics (range: -3.1% to 30.7%).  Changes in the proportion of visits with a CT/GC diagnosis before and after the change in screening practices were 4.9%, 1.1%, and -7.3% for patients seen at high, medium, and no improvement/decrease clinics, respectively.  In multivariate models, the odds ratio of CT/GC diagnoses during the post- vs pre-protocol period was 1.37 (95%CI: 1.05-1.78; p=0.02) and 1.40 (95%CI: 1.12-1.76; p<0.01) times greater at high and medium improvement clinics compared to the no improvement/decrease clinics.  

Conclusions: When followed, a universal extra-genital CT/GC screening protocol for MSM was effective at identifying additional infections, adding to the literature that exposure-based screening for MSM contributes to undiagnosed infection.