The extent of undiagnosed HIV infection among emergency department patients: results of a blinded seroprevalence survey and a pilot HIV testing program.

This study was performed to determine the rate of previously undiagnosed HIV infection among patients presenting to an urban emergency department (ED) and to assess the feasibility of routinely offering voluntary HIV testing in this setting. HIV serostatus was determined anonymously among consecutive acute medicine and trauma ED patients (aged 18-55) who had blood drawn as part of their medical care. Excess serum was aliquoted and coded with an anonymous study code. Before performing HIV testing, the number of persons with previously reported HIV infection was determined by linkage with the state HIV/AIDS reporting registry. Concurrent with the blinded HIV serosurvey, ED patients were offered voluntary HIV testing in a pilot program. Overall, 76 of 2,155 (3.5%) adult ED patients in the blinded survey were HIV-seropositive, 15 of whom (0. 7% of those tested, 20% of those HIV-seropositive) had no infection previously reported to the state HIV/AIDS registry. In the pilot program, six of the 156 (3.8%) individuals who underwent voluntary HIV testing were HIV-seropositive, including three of 53 (5.6%) individuals without prior HIV testing. Of the six HIV-seropositive subjects, one was previously diagnosed, while five of the remaining 155 (3.2%) represented previously undiagnosed infections. Overall, 3. 5% of ED patients from whom blood was obtained for other reasons tested positive for HIV antibody, 20% of whom were previously undiagnosed. Implementation of the voluntary testing program uncovered newly diagnosed infection among 3.2% of those tested. An ED may be an important setting for routinely offering HIV testing, especially for patients who have not been previously tested for HIV.