Anti-HIV-1 antibody testing using modified gelatin particle agglutination: a large field study

Area of Science:

• Medical Diagnostics
• Virology
• Public Health

Background:

• Human Immunodeficiency Virus (HIV) remains a significant global health concern.
• Accurate and cost-effective diagnostic assays are crucial for HIV surveillance and control.
• Enzyme-linked immunosorbent assays (ELISAs) are standard for HIV testing, but cost can be a barrier for large-scale screening.

Purpose of the Study:

• To evaluate the cost-effectiveness and diagnostic performance of modified gelatin particle agglutination (GPA) assays for anti-HIV-1 testing.
• To compare modified GPA assay performance against standard ELISA methods in diverse populations.
• To determine the suitability of modified GPA for routine screening of large sample volumes.

Main Methods:

• Two modified gelatin particle agglutination (GPA) assay strategies were implemented in parallel with ELISAs.
• Strategy 1: Reduced GPA reagent volumes for a general patient population (n=174,032) with high HIV-1 seroprevalence (13.72%).
• Strategy 2: Pooled sera (4 sera/pool) using manufacturer's recommended GPA volumes for pregnant women (n=90,560) and emigrant workers (n=48,936) with lower HIV-1 seroprevalence (2.2% and 0.3%).

Main Results:

• Modified GPA assays demonstrated significant cost reductions: 40% in strategy 1 and 67% in strategy 2.
• The sensitivity and specificity of the modified GPA assays were comparable to standard ELISA methods.
• Large-scale testing using modified GPA assays proved feasible and cost-effective.

Conclusions:

• Modified gelatin particle agglutination (GPA) assays are a cost-effective alternative for anti-HIV-1 testing in high-volume settings.
• These modified GPA assays exhibit comparable sensitivity and specificity to standard methods.
• However, modified GPA assays are not recommended as a first-line diagnostic or blood bank screening assay, especially in areas with high HIV infection rates.