Active Surveillance of Powassan Virus in Massachusetts Ixodes scapularis Ticks, Comparing Detection Using a New...

Area of Science:

• * Vector-borne disease research
• * Molecular diagnostics
• * Tick-borne pathogen surveillance

Background:

• * Powassan virus (POWV) is an emerging tick-borne pathogen causing severe neuroinvasive disease.
• * Increasing incidence and geographic range of human POWV necessitate sensitive detection methods.
• * Accurate diagnostics and surveillance are critical for managing POWV spread.

Purpose of the Study:

• * Develop a sensitive, simultaneous detection method for POWV and deer tick virus (DTV, POWV lineage II).
• * Quantify viral presence in Ixodes scapularis ticks using a novel assay.
• * Assess DTV prevalence in tick populations in Massachusetts to understand geographic variation.

Main Methods:

• * Developed a Taqman-based triplex real-time PCR assay for simultaneous POWV and DTV detection.
• * Incorporated an exon-exon junction internal control for RNA quality and extraction validation.
• * Surveyed DTV in Ixodes scapularis ticks across 13 sites on Cape Cod and Martha's Vineyard.

Main Results:

• * The developed real-time PCR assay demonstrated higher sensitivity compared to the Luminex xMAP MultiFLEX Vector-borne Panel 2.
• * Powassan virus infection rates in ticks ranged from 0.0% to 10.4%, indicating fine-scale geographic variability.
• * The assay successfully detected DTV in tick populations within highly endemic areas.

Conclusions:

• * The novel triplex real-time PCR assay provides a sensitive and quantitative tool for detecting POWV and DTV in ticks.
• * The findings highlight significant geographic variations in DTV presence in Massachusetts tick populations.
• * This PCR assay is suitable for adoption in broader Powassan virus surveillance programs.