A long-term sustainability study of air filtration was completed recently to assess its value in reducing the occurrence of new infections by porcine reproductive and respiratory syndrome (PRRS).

Thirty-eight herds were studied at three different levels from September 2008 to January 2012 including the likelihood of infection in filtered and non-filtered herds.

Results indicate that new PRRS virus infections in filtered barns in large breeding herds in swine-dense regions were significantly lower than in non-filtered control herds.

The odds for a new PRRS infection in breeding herds before filtration was installed was 7.97 times higher vs. the odds after filtration was initiated. And the median time to new PRRS infections in filtered breeding herds of 30 months was significantly longer than the 11 months observed in non-filtered herds.

The authors of the study from the University of Minnesota and a group of southern Minnesota swine veterinary practices conclude across all three levels of analysis that the long-term effect of air filtration on reducing the occurrence of new PRRS infections in the study population was demonstrated.

The article appeared in the latest e-newsletter of the American Association of Swine Veterinarians (www.aasv.org.)