In 2011, Arizona’s principal safety net emergency department (ED) implemented universal opt-out HIV screening using a new (fourth-generation) test that detects both HIV antigen and anti-HIV antibody (Architect HIV Ag/Ab Combo Test; Abbott Laboratories). All positive results were confirmed by Western blot testing. Patients aged 18 to 64 undergoing venipuncture as part of their ED care were informed at triage that they would be tested and were given an informed-consent brochure; at this time they could opt out.
During 2011 to 2014, nearly 28,000 HIV tests were performed on 22,500 patients. The test was positive in 105 cases (0.38%), but 27 (26%) were found to be false-positive results on confirmatory testing. There were 78 confirmed HIV diagnoses (0.28% of all tests), and of these, 18 (23%) were acute infections. Overall, 35% of patients declined testing.