Background: The Centers for Disease Control and Prevention (CDC) estimates that 1.1 million Americans are living with HIV, yet 15% remain unaware of their HIV status. The ED is a key location in detecting undiagnosed HIV. The CDC issued HIV testing guidelines in 2014 to improve acute phase HIV detection: first, a combination immunoassay (CI) for HIV-1/2 antibodies (Ab) and HIV-1 p24 antigen (Ag); second, an HIV-1/2 antibody differentiation immunoassay (DI) if CI is reactive; third, HIV-1 nucleic acid (NA) testing for specimens reactive on CI but nonreactive/indeterminate on DI. However, adherence to these guidelines in the ED setting remains challenging, given workflow and limited continuity of care. The Cleveland Clinic Main Campus (CCMC) ED began using point-of-care (POC) Alere Determine HIV-1/2 Ag/Ab CI in January 2016. Since we noted increased incidence of positive POC CI results with negative DI, our objective was to review our current HIV screening process to ensure compliance with CDC guidelines
Methods: This study was a retrospective qualitative analysis of CCMC ED HIV test logs from January 2016 to January 2018. Charts of patients with positive CI results were examined to assess what follow-up HIV testing was performed, as well as patient education in the ED and follow-up HIV-related care. Data was recorded with a standardized collection sheet, and basic descriptive statistics were calculated.
Results: There were 26 positive results from the POC CI: 11 patients had a reactive HIV-1 result from an ED-based DI; 10 had a non-reactive DI (positive CI as follows: 7 Ab+/Ag-, 2 Ab-/Ag+, and 1 indeterminate result requiring further testing); 2 had delayed/inappropriate follow-up (non-ED DI); and 3 were known HIV+. Under 2014 CDC guidelines, the 10 non-reactive DI needed HIV-1 NA testing; however, only 2/10 had a valid HIV RNA test. Excluding patients with known HIV+ status, 18/23 patients with a new positive CI result accessed follow-up care to discuss the CI result and implications: 11/11 with reactive DI, but only 7/12 for non-reactive DI or non-ED DI.
Conclusion: There was a low incidence of follow-up HIV-1 NA testing following a negative DI in accordance with CDC guidelines, which may delay or hinder HIV diagnosis and access to follow-up care, particularly in patients with acute phase HIV. Adherence to CDC guidelines in the ED setting may improve by bundling HIV tests, such as the DI and NA.