New PRRSV strain undetected by routine PCR

http://www.aasv.org/news/story.php?id=3770

17-Sep-2009 (16 years 8 months 21 days ago)
Recently a PRRSV boar stud infection went undetected through the routine PCR monitoring protocol. Results from the investigation suggest that a new PRRSV strain has emerged.

This new strain has a new cut pattern defined as 3-4-2 and varies markedly from the other 22 standard reference strains, including vaccine strains, used for comparison purposes. The new strain variation to the closest and more distant reference strains is significant at 8.3% and 18% respectively.

As new and genetically diverse PRRSV strains emerge, it must be realized that PCR-based techniques will not always be able to detect every new strain 100% of the time. PCR-based techniques use very specific and sensitive primers that need to be adapted continuously to detect emerging strains.