Comparison of two automated methods for detection and differentiation of herpes simplex virus in clinical specimens

The Aptima Herpes Simplex Virus (HSV) 1&2 Assay recently received Health Canada approved for detection and differentiation of HSV-1 and HSV-2 from anogenital sites. This assay uses target capture, transcription mediated amplification, and real-time detection of messenger RNA (mRNA) produced in host cells during active HSV infection. To evaluate its performance, the Aptima assay was compared to another Health Canada approved assay, the BD ProbeTec Herpes Simplex Viruses HSV 1&2 Qx Amplified DNA Assay, which uses strand displacement amplification technology.

As recommended by the manufacturers, the Aptima and ProbeTec assays were performed on the Panther and Viper instruments, respectively. Analytical sensitivity and specificity were assessed using 10-fold serial dilution of viruses in viral universal transport media (UTM), and nucleic acids extracted and concentrated from other viruses including all members of the Herpesviridae family. The clinical sensitivity and specificity were assessed retrospectively using 60 archived specimens, and prospectively using 158 swabs in UTM. Discrepant results were resolved with real-time PCR using the Altona Diagnostics RealStar alpha Herpes assay.

Both the Aptima and ProbeTec assays showed excellent analytical and clinical specificity. However, the Aptima HSV assay failed to detect HSV in specimens with low viral loads, resulting in reduced sensitivity for HSV-2 during the retrospective evaluation at 85.0%, and for HSV-1 at 85.0% during the prospective evaluation.

This study compared the Aptima and ProbeTec HSV assays and demonstrated that detection of HSV mRNA using the Aptima HSV assay was less sensitive in both retrospective and prospective analyses.