Emerging PRRS Virus 3-4-2 Update

September 30, 2009 — 

A recent report from the Veterinary Diagnostic Laboratory at the University of Minnesota regarding an apparent failure to detect a newly emerging PRRS virus has raised concerns regarding the sensitivity of some current diagnostic tests. The 3-4-2 PRRS virus was not detected by NAEU Taqman PCR routinely used at the diagnostic lab although it was later detected by a commercially available Ambion PCR test, Also, at that time, it was stated that the new strain was "hit and missed by the Tetracore test suggesting lower test sensitivity in pooled samples."

Since that time, researchers at the diagnostic lab have continued to explore the diagnostic challenges with this strain and Dr. Jim Collins, Director of the University of Minnesota Veterinary Diagnostic Laboratory, offers the following update on the current understanding.

"Further analysis of sera containing the 3-4-2 PRRSV at the South Dakota Animal Disease Research and Diagnostic Laboratory and the University of Minnesota Veterinary Diagnostic Laboratory confirm that the Tetracore PRRSV PCR test consistently detects the 3-4-2 PRRSV. The initial report of "hit and miss" was based on preliminary information from a third laboratory which has proven to be incorrect. The concern in the early communication was to err on the side of safety until further analysis of the 3-4-2 was available. The University of Minnesota Veterinary Diagnostic Laboratory will continue to forward 3-4-2 PRRSV RNA to other laboratories for analysis with their PRRSV PCR tests."

For more information contact Dr. Kurt Rossow at the University of Minnesota Veterinary Diagnostic Laboratory at 1-800-605-8787 or by email at: rosso003@umn.edu