Background:
ELISA is used for the detection of antibodies to the herpes simplex virus type 2 (HSV-2) Glycoprotein gG-2. However, some assays have high sensitivity values, but low specificity values or vice versa that can lead to false diagnosis.

Objective:
Western Blot is used as the “gold standard” against which to compare Focus and Kalon ELISA along with Sure-Vue Rapid test in order to identify an effective test combination for HSV-2 antibodies.

Method:
1238 sera samples of a low-risk population (Vietnamese HIV uninfected housewives in peri-urban Hanoi) were initially screened for HSV-2 antibodies with Focus ELISA. Out of this population, 174 selected sera samples including all positive samples were confirmed by Western Blot, Kalon ELISA, and Sure-Vue Rapid test.

Result:
Based on Western blot results, there were 25 positive sera in this population. Sensitivity for Focus, Kalon & Rapid tests were 100%, 88%, and 80% respectively. However, the specificity for the Focus test was 93% with 83 false positive results. When using a combination of an initial screening of the Focus ELISA followed by confirmatory testing by Kalon ELISA, the specificity value increased to 97.9% with a decline of 25 false positives. Confirmatory Sure-Vue Rapid test of Focus ELISA showed 98% specificity with 21 false positives.

Conclusion:
Confirmatory Kalon ELISA and Sure-Vue Rapid testing of Focus HSV-2 ELISA positive samples appears to be an effective and convenient method to reduce falsely positive HSV-2 antibody results. This simple, yet effectual HSV-2 serologic test combination enhanced specificity.

Implications:
Because of the limitation of Western blot in developing countries due to cost and availability, we believe that clinicians and laboratories could benefit from the combination of the confirmatory testing with Kalon ELISA and/or Sure-Vue Rapid test of Focus HSV-2 ELISA to produce accurate and cost-effective results.