Finding those at risk: acute HIV infection in Newark, NJ

Abstract

Background: A screening strategy combining rapid HIV-1/2 (HIV) antibody testing with pooled HIV-1 RNA testing increases identification of HIV infections, but may have other limitations that restrict its usefulness to all but the highest incidence populations.

Objective: By combining rapid antibody detection and pooled nucleic acid amplification testing (NAAT) testing, we sought to improve detection of early HIV-1 infections in an urban Newark, NJ hospital setting.

Study design: Pooled NAAT HIV-1 RNA testing was offered to emergency department patients and outpatients being screened for HIV antibodies by fingerstick-rapid HIV testing. For those negative by rapid HIV and agreeing to NAAT testing, pooled plasma samples were prepared and sent to the University of Washington where real-time reverse transcription-polymerase chain reaction (RT-PCR) amplification was performed.

Results: Of 13,226 individuals screened, 6381 had rapid antibody testing alone, and 6845 agreed to add NAAT HIV screening. Rapid testing identified 115 antibody positive individuals. Pooled NAAT increased HIV-1 case detection by 7.0% identifying 8 additional cases. Overall, acute HIV infection yield was 0.12%. While males represent only 48.1% of those tested by NAAT, all samples that screened positive for HIV-1 RNA were obtained from men.

Conclusion: HIV-1 RNA testing of pooled, HIV antibody-negative specimens permits identification of recent infections. In Newark, pooled NAAT increased HIV-1 case detection and provided an opportunity to focus on treatment and prevention messages for those most at risk of transmitting infection. Although constrained by client willingness to participate in testing associated with a need to return to receive further results, use of pooled NAAT improved early infection sensitivity.

Keywords: HIV screen; HIV seronegativity; HIV testing algorithms; NAAT; Nucleic acid amplification tests; Rapid HIV tests.

Fig. 1

Testing flowchart – patients were approached in the Emergency Department and in an Outpatient Clinic at University Hospital, Newark, NJ and offered rapid HIV screening. After rapid HIV screening, using the StatPak Rapid HIV 1/2 test (Alere North America, Inc., Princeton, NJ), those determined to be negative (13,111) were offered an opportunity to participate in pooled nucleic acid amplification testing (NAAT). Plasma samples were collected, centrifuged and stored frozen from those agreeing (6845) until a 27 sample batch could be pooled and transported to the University of Washington, Center for AIDS Research (CFAR) for analysis.