Evidence of Airborne Transmission of PRRSV and Mycoplasma

This is the first evidence of long-distance airborne transmission of porcine reproductive respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae, writes Janet Alsop of the veterinary disease prevention department at the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).

10 March 2009

2 minute read

At the most recent Big Bug Day, Dr Scott Dee presented data on the effectiveness of different methods of filtering incoming air in swine barns. In his model, he found that MERV 14 filters or antimicrobial filters were effective in preventing aerosol spread of porcine reproductive respiratory syndrome virus (PRRSV). These filters are considerably less expensive than HEPA filters. Further testing of these options in large scale field trials is required before specific recommendations can be made.

Barn filtration needs to be applied year-round and not only in the higher risk winter months. Dr Dee found that, in his model, both PRRSV and M. hyopneumoniae were transmitted to non-filtered barns during the summer months.

Long distance airborne spread of PRRSV and M. hyopneumoniae can occur if the weather conditions are 'correct', i.e. low winds, high humidity and cool temperatures.

During a trial in the fall of 2008, Dr Dee collected air samples in the early morning hours and was able to detect both of the pathogens 3.3 kilometres from an infected source population.

This is the first evidence of long distance aerosol transport of PRRSV.

This summary is based on a presentation by Dr Scott Dee at Big Bug Day VI on 3 December 2008.

March 2009