Detection of diverse HIV strains by the m-PIMA^TM HIV-1/2 detect point-of-care assay

HIV displays exceptionally high virus diversity that can impact detection by diagnostic assays, which rely on sequence conservation.

We tested the m-PIMA HIV-1/2 Detect point-of-care (POC) assay (Abbott Rapid Diagnostics) against a diverse HIV panel of 340 serum/plasma specimens and diluted cultured virus isolates for which viral load (VL) and classified sequences were known, including HIV-1 groups M, N, O, P, Circulating Recombinant Forms (CRF), and Unique Recombinant Forms (URF), and HIV-2. An in silico inclusivity analysis of 53,503 HIV-1 and 68 HIV-2 sequences from NCBI was performed to predict performance of m-PIMA HIV-1/2 Detect against a broader range of circulating strains.

m-PIMA HIV-1/2 Detect detected HIV in 329/340 (96.8 %) tested samples. The mean VL was 3.80 (2.09-6.14) log copies/mL. Among samples with HIV VL >4000 copies/mL (3.60 log copies/mL; m-PIMA HIV-1/2 Detect design sensitivity), 181/181 (100 %) were detected. Among samples with VL between 3.0 and 3.6 log copies/mL, m-PIMA HIV-1/2 Detect detected 93/96 (96.9 %), and 55/63 (87.3 %) samples with VL below 3.0 log copies/mL were detected. At least one member from each subtype/CRF and all URFs were detected. In silico analysis identified 2/53,503 (0.0037 %) HIV-1 (both group O) and 1/68 (1.47 %) HIV-2 (subtype F) sequences with target region mutations that decreased identity below a 90 % threshold.

The m-PIMA HIV-1/2 Detect assay detected each of the major circulating HIV strains, including rare divergent strains. In silico analysis predicted that m-PIMA HIV-1/2 Detect would detect the majority of HIV-1 and HIV-2 strains indicating that this assay can detect the full range of HIV viral diversity.