Detecting acute human immunodeficiency virus infection using 3 different screening immunoassays and nucleic acid...

The yield of nucleic acid amplification testing (NAAT) after routine screening for human immunodeficiency virus (HIV) antibody to detect acute HIV infection (AHI) may vary with different HIV-antibody assays.

From April 24, 2006, through March 28, 2008, patients underwent routine HIV-antibody screening using a first-generation assay at 14 county sexually transmitted disease (STD) clinics and 1 community clinic serving homosexual patients in Los Angeles; using a second-generation rapid test at 3 municipal STD clinics in New York; and using a third-generation assay at 80 public health clinics in Florida. To identify AHI, seronegative specimens were pooled for NAAT, followed by individual NAAT of specimens with positive findings. All AHI samples screened by first- and second-generation assays also underwent third-generation testing.

We screened 37 012 persons using NAAT after first-generation testing; 35 AHIs were identified, increasing HIV case detection by 8.2%. After a second-generation rapid test, 6547 persons underwent NAAT; 7 AHIs were identified, increasing HIV case detection by 24.1%. After third-generation testing, 54 948 persons underwent NAAT; 12 AHI cases were identified, increasing HIV case detection by 1.4%. Overall, pooled NAAT after negative third-generation test results detected 26 AHI cases, increasing HIV case detection by 2.2%. Most of the AHI cases from Los Angeles (26 of 35 [74%]) were identified at the community clinic where NAAT after third-generation testing increased HIV case detection by 11.9%.

Pooled NAAT after third-generation testing increases HIV case detection, especially in venues of high HIV seropositivity. Therefore, targeted AHI screening using pooled NAAT after third-generation testing may be most effective, warranting a cost-benefit analysis.