Gonorrhea, Chlamydia and HIV Coinfection in Alameda County

Background: Gonorrhea (GC) and Chlamydia (CT) infections in persons living with HIV (PLWH) indicate ongoing sexual risk behavior. Coinfected persons may transmit HIV, GC, or CT to sex partners. We sought to describe HIV coinfection and viral load (VL) among reported GC and CT cases in Alameda County, California. 

Methods: GC and CT surveillance data from May 1, 2015 to March 31, 2016 were matched to HIV surveillance data to identify coinfected cases. Pearson’s chi-square was used to test for differences by disease coinfection, VL results, and time since most recent VL prior to the reported GC or CT infection.

Results: There were 1,747 GC and 4,843 CT cases reported and 68 dual-infections. Among 6,658 total GC and CT cases, we found 306 (4.6%) coinfected with HIV, including 11 with new HIV diagnoses. Among new cases, the HIV coinfection rate was 7.2% (125/1747) for GC and 2.5% (119/4843) for CT. Of 295 coinfected cases with previously diagnosed HIV, 77.3% (228) had an undetectable VL (<76 HIV-1 RNA copies/mL), 21.7% (64) had a detectable VL, and 1.0% (3) had no reported VL. Additionally, 29.7% of those with a detectable VL were from specimens drawn >180 days prior to their GC or CT infection compared to 10.5% of those with an undetectable VL (p< 0.001). Excluding dual-infections, 28.1% (114/230) HIV/GC coinfected cases had a detectable VL compared to 15.5% (116/230) of HIV/CT (p=0.021). 

Conclusions: HIV coinfection is not uncommon among reported GC and CT cases; over 21% of coinfected cases have a detectable VL, demonstrating risk for HIV transmission.  Coinfection information can be used to inform partner services, linkage to care, testing and PrEP referrals for GC and CT cases. Real-time matching of HIV and STD surveillance data would enhance delivery of tailored HIV prevention and care service.