What are HIV and AIDS?

HIV is a virus that specifically targets the immune system, weakening the body¡¯s ability to fight infections and diseases, making individuals more susceptible to opportunistic infections and certain cancers. It can be transmitted through specific bodily fluids, including blood, semen, vaginal fluids, and breast milk. ^[1]

?

AIDS is the advanced stage of HIV infection, occurring when the immune system is severely compromised, leaving the body vulnerable to opportunistic infections and certain cancers. ^[1]

HIV prevalence

At the end of 2023, an estimated 39.9 million people are living with HIV globally, and about 42.3 million individuals have died due to complications related to HIV/AIDS. The African region is the most severely affected, with 1 in every 30 adults (approximately 3.4%) living with HIV, which accounts for more than two-thirds of all individuals currently living with HIV worldwide. ^[2]

The challenge of screening for HIV

HIV can impact individuals irrespective of sexual orientation, race, ethnicity, gender, age, or geographical location. It represents a major global health concern characterized by a substantial number of infections and significant mortality rates. The definitive method to ascertain HIV status is through testing. However, public health systems globally encounter obstacles in accurately screening for HIV due to the possibility of false positives.

Addressing the challenge

To address the challenges posed by the current HIV screening and confirmatory assays, it is essential to explore alternative approaches that balance sensitivity, specificity, and cost-effectiveness. In the study, the researchers aimed to evaluate the performance of the new cost-effective Mindray CL-900i-HIV Ag/Ab combo assay as an alternative screening method to the well-established ARCHITECT? HIV Ag/Ab combo assay. Additionally, they compared the performance of the Mindray CL-900i-HIV Ag/Ab combo assay against the gold standard INNO-LIA? HIV I/II confirmatory assay. The evaluation also included a surrogate reference method, PCR. The findings aim to provide valuable insights for healthcare professionals to enhance the effectiveness of HIV screening protocols and diagnostics.

The study analyzed retrospective data from a large group of individuals who underwent HIV screening at the MC between 2022 and 2023 using the Architect-HIV assay. From this dataset, 195 samples were specifically chosen based on their alignment and disparities between the ARCHITECT? HIV Ag/Ab combo assay and the gold standard, INNO-LIA? HIV I/II confirmatory assay. These samples included cases testing positive by both methods, cases positive only by the ARCHITECT? assay, cases with indeterminate results, and cases negative by both assays. All selected samples underwent re-testing using the Mindray CL-900i-HIV Ag/Ab combo assay, with positive ARCHITECT? results further confirmed via PCR. This rigorous process aimed to comprehensively assess the accuracy of the Mindray CL-900i-HIV assay, particularly focusing on samples potentially prone to false-positive outcomes, thus providing strong evidence for its efficacy and viability as an alternative screening method.

The Mindray CL-900i-HIV Ag/Ab combo assay is a 2-site sandwich CLIA. It utilizes monoclonal antibodies and HIV-1 or HIV-2 antigens coated on microparticles, enabling simultaneous testing for both antigens and antibodies associated with HIV infection. The procedure involves combining the sample with assay diluent and paramagnetic microparticles coated with HIV antigens and antibodies, followed by a chemiluminescence reaction that is measured as relative light units (RLUs). The assay demonstrates high sensitivity and specificity compared to the gold standard INNO-LIA? HIV I/II confirmatory assay, with no false positives reported.

Reference:

[1]. What Are HIV and AIDS? HIV. Gov. available from: What Are HIV and AIDS? | HIV.gov

[2]. HIV. The Global Health Observatory. World Health Organization. 2024.