Undiagnosed HIV and HCV infection are missed opportunities for care and prevention of secondary transmission. CDC estimates that 13% of HIV-infected and 50% of HCV-infected persons nationwide are undiagnosed/unaware of their infection; a blinded Emergency Room (ER) HIV serosurvey in New York City (NYC) in 2010 found 14% undiagnosed/unaware. We sought to measure the prevalence of HIV and HCV, the proportion of undiagnosed/unaware, and the proportion coinfected in persons presenting to a high-volume NYC ER in 2015.
We conducted a blinded cross-sectional serosurvey using remnant serum from specimens originally drawn for clinical indications. Serum was deduplicated and matched to (1) the hospital’s electronic medical record for demographic and clinical data and (2) the HIV and HCV surveillance registries for evidence of previous diagnosis prior to being de-identified and tested using standard 2- and 3-step clinical testing protocols.
Among unique individuals successfully tested for HIV, 250/4990 (5.0%, 95% CI 4.4,5.7) were positive for HIV infection. Among patients tested for HCV, 372/4989 (7.5%, 95% CI 6.7,8.2) were anti-HCV-antibody positive; 196 (3.9%, 95% CI 2.8,5.1) were positive by HCV RNA PCR, indicating current infection. Overall, 12/250 patients testing positive for HIV (4.8%, 95% CI 2.5,8.2) were undiagnosed; 148/372 persons testing positive for anti-HCV antibody (39.8%, 95% CI 34.8,45.0) were undiagnosed; and 38/196 (19.2%, 95% CI 11.4,27.0) patients with detectable HCV RNA were undiagnosed. Among 250 HIV-positive individuals, 246 had sufficient serum for HCV testing; 79 (32.1%; 95% CI 26.3,38.3) were HCV-antibody positive, and 39 (15.7%, 95% CI 7.4,24.0) were currently HCV infected. Among 372 anti-HCV-positive patients, 79 (21.2%, 95% CI 17.2,25.8) were HIV-positive; among 196 HCV-infected patients, 39 (19.4%, 95% CI 12.8,26.0) were HIV-positive.
A reduction in the proportion of HIV-infected but undiagnosed/unaware persons presenting to the NYC ER setting between 2010 and 2015 was coterminous with legislation, funding and aggressive programming to increase HIV testing and diagnosis in NYC. Undiagnosed HCV was high, suggesting that initiatives similar to those directed toward HIV should be mounted to improve HCV diagnosis and linkage to care and treatment.