A rapid and simple isothermal nucleic acid amplification test for detection of herpes simplex virus types 1 and 2

A simple and rapid IsoAmp HSV assay has been developed for qualitative detection of herpes simplex virus (HSV) types 1 and 2 from genital lesions. Sample preparation involved a simple dilution step and the diluted specimens were directly added to the device and amplified by isothermal helicase-dependent amplification (HDA). Amplification products were then detected by a DNA strip embedded in a disposable cassette without any instrument. The total test turn-around time is less than 1.5h from specimen processing to result reporting.

To evaluate the analytical and clinical performance of the IsoAmp HSV assay as well as the robustness and reproducibility of the assay.

The analytical sensitivity of the IsoAmp HSV assay was determined using both HSV-1 and HSV-2. Clinical performance was evaluated using 135 frozen specimens collected from patients with suspected HSV infection in genital area.

The analytical sensitivity of the assays was 5.5 and 34.1 copies/reaction for HSV-1 and HSV-2 respectively with a 95% confidence interval. When the herpes viral culture was used as the reference standard, the clinical sensitivity and specificity of the IsoAmp HSV assay were 100.0% and 96.3% respectively. The inter-laboratory reproducibility achieved an overall 97.5% agreement by testing a total of 80 blinded HSV-1 samples among five laboratories.

Adequate analytical and clinical performance of the IsoAmp HSV assay was demonstrated. This assay is simple to perform and has acceptable inter-laboratory reproducibility.