Article Text
Abstract
Background: In certain parts of Africa, type-specific HSV type-2 ELISAs may have limited specificity. To date, no study has been conducted to validate HerpeSelect and Kalon type-specific HSV-2 ELISAs using both the Western blot (WB) and Recombinant gG ELISA inhibition testing as reference standards.
Methods: A total of 120 HIV-seronegative men (aged 18-24 years) provided blood samples. HSV-2 IgG serum antibodies were detected using four different methods: i. HerpeSelect HSV-2 ELISA (n=120), ii. Kalon HSV-2 ELISA (n=120), iii. University of Washington WB (n=101), and iv. a recombinant inhibition test (n=93).
Results: HSV-2 seroprevalence differed significantly by HSV-2 detection method, ranging from 24.8% with the WB to 69.8% with the HerpeSelect ELISA. Using the WB as the reference standard, the HerpesSelect had the highest sensitivity for HSV-2 antibody detection (100%), yet lowest specificity (40%). Similar results were obtained using the inhibition test as the reference standard. The sensitivity and specificity of the Kalon test were 92% and 79%, respectively, versus the WB; and 80% and 82% versus the inhibition test. Using the inhibition test as the reference standard, the sensitivity of the WB appeared low (49%).
Conclusions: In HIV-seronegative men in Western Kenya, the HerpeSelect and Kalon type-specific ELISAs had high sensitivities yet limited specificities using the WB as reference standard. Overall, the Kalon ELISA performed better than the HerpeSelect ELISA in these high-risk young men from Kisumu. Further understanding is needed for the interpretation of HSV-2 inhibition or ELISA test positive/WB seronegative results. Before HSV-2 seropositivity may be reliably reported in selected areas of Africa, performance studies of HSV-2 serological assays in individual geographical areas are recommended.