US - Three separate strains of influenza A virus (IAV) have been detected in animal and environmental samples taken from six swine farms in southern Minnesota and northern Iowa with suspected flu outbreaks.
Five of the outbreaks were confirmed to be caused by IAV. Of those, 48 per cent (47/98) of oral fluid, 38 per cent (32/84) of pen railing, and 43 per cent (35/82) of indoor air samples tested positive for influenza A by polymerase chain reaction.
Among the five outbreak farms, H1N1 was confirmed on one, H3N2 on one, both H1N1 and H1N2 on two farms, and both H1N1 and H3N2 on one farm.
The authors concluded: "We found that IAV could be isolated from indoor air of commercial swine production facilities, that airborne IAV levels were sustained for periods of 20 days and that there was a correlation between the number of positive samples of each type and the quantity of virus in the swine oral fluids and in the air.
"Our results provide a first estimation on levels of environmental IAV in swine commercial production facilities, and thus an assessment of potential sources of IAV exposure to swine workers or other pigs."
ThePigSite News Desk
Top image via Shutterstock