Method for tick-borne encephalitis virus detection in raw milk products.

Area of Science:

• Food Safety
• Molecular Biology
• Virology

Background:

• Tick-borne encephalitis virus (TBEV) transmission via food is uncommon but documented, primarily through raw milk products from infected animals.
• A 2020 outbreak in France linked TBEV to unpasteurized goat cheese, highlighting the need for reliable detection methods.
• Current diagnostic methods require validation against international standards for food matrices.

Purpose of the Study:

• To develop and validate a molecular detection method for TBEV in raw milk products.
• To characterize the method's performance according to the international standard PR ISO/DIS 16140-4.
• To ensure the method's suitability for routine diagnostic use and risk assessment.

Main Methods:

• Development of a molecular detection assay for TBEV in raw milk.
• Characterization of the method based on PR ISO/DIS 16140-4, including recovery rates and limits of detection (LOD50, LOD95).
• Assessment of RT-qPCR inhibition and validation using murine norovirus (MNV-1) as a process control.

Main Results:

• The developed method demonstrated variable TBEV recovery rates dependent on inoculation levels and experimental settings.
• The limits of detection (LOD50 and LOD95) were determined to be 6.40 × 10^3 and 2.84 × 10^4 genome copies/g or mL, respectively.
• RT-qPCR inhibition levels remained below 75%, and MNV-1 was consistently detected, indicating method robustness.

Conclusions:

• The validated molecular method is suitable for the routine detection of TBEV in raw milk products.
• This assay can significantly contribute to monitoring and managing potential TBEV health risks in dairy.
• The method adheres to international standards, ensuring reliable and comparable diagnostic results.