Classical swine fever virus: a ring test to evaluate RT-PCR detection methods.

Area of Science:

• Veterinary Virology
• Molecular Diagnostics
• Food Animal Health

Background:

• Classical swine fever virus (CSFV) poses a significant threat to swine populations globally.
• Accurate and sensitive diagnostic tools are crucial for controlling CSFV outbreaks.
• Reverse transcription-polymerase chain reaction (RT-PCR) is a key molecular method for viral detection.

Purpose of the Study:

• To evaluate the sensitivity and specificity of various RT-PCR tests for CSFV detection.
• To compare the performance of different RT-PCR assays used by multiple laboratories.
• To assess the reliability of RT-PCR compared to traditional methods like virus isolation and ELISA.

Main Methods:

• Six laboratories participated in a comparative exercise using coded samples.
• Samples included serial dilutions of CSFV, synthesized cDNA, and clinical specimens (tonsil, spleen, blood, serum).
• Laboratories employed their routine PCR/RT-PCR methods for sample analysis.

Main Results:

• Both RT-PCR and RT-nested PCR assays showed potential for CSFV detection.
• Some RT-PCR tests exhibited false positive results, indicating a need for optimization.
• Comparison with virus isolation and antigen ELISA highlighted variability in RT-PCR performance.
• Limited comparisons of extraction and reverse transcription procedures yielded similar results across labs despite non-standardized methods.

Conclusions:

• Several RT-PCR tests demonstrate suitability for CSFV detection regarding sensitivity and specificity.
• Further inter-laboratory trials are essential to standardize protocols and validate test performance.
• Improved control procedures are necessary to mitigate issues related to false positive reactions in CSFV diagnostics.