RCPAQAP Serology offers modules for the detection of HIV using a number of methodologies including HIV-specific serological assays and more recently point of care tests. Participation by diagnostic laboratories and clinics in External Quality Assurance (EQA) HIV proficiency testing programs is essential to ensure accurate, clinically relevant and timely delivery of laboratory results. Retrospective review of results was undertaken to assess the accuracy of HIV detection and identification using various methods. In 2016, 20 specimens were distributed; 9 negative and 11 positive specimens which included HIV antigen, HIV-1 antibody and HIV-2antibody. Assigned results are determined by a consensus of ≥ 80%.
Review of the HIV Serology module showed 141 participants used testing methods including but not limited to enzyme immunoassays, immunochromatographic tests and western blot assays. Overall, there was an accuracy rate of 99% for HIV detection. Of the participants performing HIV Ab/Ag combination assays, 99% correctly identified HIV Ag/Ab negative specimens and 98% correctly identified HIV Ag or Ab positive specimens. Confirmatory testing was performed by 23% of participants with 93% of these participants accurately confirming reactive specimens.
HIV point of care tests are used as a screening test for result interpretation at the same visit. Review of the HIV Point of Care module showed 44 participants used a variety of devices to identify HIV antibodies/antigens. Participants accurately detected the presence or absence of HIV Antigen (95%) or HIV Antibody (96%).
These results reflect a high concordance of qualitative reporting by laboratories across various testing platforms and methodologies for HIV testing. Continual monitoring of laboratory performance by participating in a Quality Assurance program is important and can assist laboratories in assessing the validity of the testing method, assay performance and quality of results.