Development and partial validation of a TaqMan quantitative PCR assay to detect Cervidpoxvirus

Area of Science:

• Veterinary Virology
• Molecular Diagnostics
• Wildlife Disease Surveillance

Background:

• Mule deerpox virus (Cervidpoxvirus muledeerpox) (DPV) is an emerging disease affecting wild and captive cervids across North America.
• High mortality rates, especially in fawns, are observed in domestic cervid populations.
• The virus has expanded internationally, with recent reports in Scandinavian reindeer, necessitating improved diagnostic capabilities.

Purpose of the Study:

• To develop and partially validate a standardized diagnostic test for Cervidpoxvirus detection.
• To address the lack of a standard protocol for identifying DPV, crucial for disease management.

Main Methods:

• Development of a TaqMan quantitative PCR (qPCR) assay targeting the highly conserved major capsid protein gene of DPV.
• Assay design followed World Organization for Animal Health guidelines.
• Validation included analytical and diagnostic performance assessments against existing methods.

Main Results:

• The qPCR assay demonstrated 100% agreement for amplifying an 83 bp region of the major capsid protein gene, which is >99% conserved across available DPV genomes.
• Analytical validation indicated the assay is specific to DPV and highly sensitive, with a limit of detection ≥10 DNA copies.
• Diagnostic performance showed the qPCR assay is 100 times more sensitive than conventional PCR.

Conclusions:

• The developed TaqMan qPCR assay provides a faster and more efficient method for Cervidpoxvirus detection.
• This validated assay will assist researchers and veterinarians in diagnosing DPV and preventing its further transmission.
• Improved diagnostics are essential for managing the expanding geographical range of this significant cervid pathogen.