Undiagnosed HIV infection among New York City jail entrants, 2006: results of a blinded serosurvey

OBJECTIVE Since 2004, when all New York City jail entrants began being offered rapid testing at medical intake, HIV testing has increased 4-fold. To guide further service improvement, we determined HIV prevalence among jail entrants, including proportion undiagnosed. METHODS Remnant serum from routine syphilis screening was salvaged for blinded HIV testing in 2006. Using HIV surveillance data and electronic clinical data, we ascertained previously diagnosed HIV infections before permanently removing identifiers. We defined "undiagnosed" as HIV-infected entrants who were unreported to surveillance and denied HIV infection. RESULTS Among the 6411 jail entrants tested (68.9% of admissions), HIV prevalence was 5.2% overall (males 4.7%; females: 9.8%). Adjusting for those not in the serosurvey, estimated seroprevalence is 8.7% overall (6.5% males, 14% females). Overall, 28.1% of HIV infections identified in the serosurvey were undiagnosed at jail entry; only 11.5% of these were diagnosed during routine jail testing. Few (11.1%) of the undiagnosed inmates reported injection drug use or being men who have sex with men. CONCLUSIONS About 5%-9% of New York City jail entrants are HIV infected. Of the infected, 28% are undiagnosed; most of whom denied recognized HIV risk factors. To increase inmate's acceptance of routine testing, we are working to eliminate the required separate written consent for HIV testing to allow implementation of the Centers for Disease Control and Prevention-recommended opt out testing model.