A molecular method for typing Herpes simplex virus isolates as an alternative to immunofluorescence methods

Area of Science:

• Virology
• Molecular Biology
• Clinical Diagnostics

Background:

• Accurate typing of Herpes simplex virus (HSV) isolates is crucial for clinical management.
• Current methods like immunofluorescence (IF) assays and polymerase chain reaction (PCR) have limitations.
• Standardizing a molecular method for HSV typing is essential for reliable identification.

Purpose of the Study:

• To compare a molecular typing method (PCR) with a commercial monoclonal antibody (MAb)-based IF test for HSV isolates.
• To evaluate the accuracy, reproducibility, and cost-effectiveness of PCR versus IF for HSV typing.

Main Methods:

• A cross-sectional study involving four reference strains and 42 patient HSV isolates.
• Testing was performed using a MAb-based IF assay and a PCR targeting the HSV polymerase (pol) gene.
• Comparison of typing results and cost analysis between the two methods.

Main Results:

• The pol PCR showed 95.7% agreement with the MAb IF assay.
• PCR identified two isolates as HSV-2 that were untypable by IF.
• PCR typing was found to be more cost-effective (USD 30) than IF typing (USD 35).

Conclusions:

• The pol PCR method is a cheaper, more reproducible, and accurate alternative for typing HSV isolates.
• PCR can potentially replace IF-based methods for routine HSV typing, especially with the increasing availability of PCR machines.
• This molecular approach offers advantages for clinical laboratories in countries like India.