Study notes evidence of airborne H5N2 1 km from affected US barns
Researchers detected H5N2 highly pathogenic avian influenza (HPAI) viruses in air samples collected inside, immediately outside, and up to 70 meters from affected barns during the 2015 outbreak in the Midwest, according to a study in this month's issue of Avian Diseases. They also found H5N2 RNA in air samples up to 1 kilometer from barns that housed infected flocks.
Researchers from the University of Minnesota and U.S. Department of Agriculture obtained air samples from 3 affected farms in Minnesota, 1 in Iowa, and 2 in Nebraska. Flock sizes ranged from 4,205 to 1.8 million poultry.
Samples were obtained inside the barns and at various distances from them to help assess the possibility of airborne spread of the disease. The investigators used polymerase chain reaction to detect live virus.
Five of the six flocks analyzed had positive air samples. Among the 382 samples tested, 33% tested positive, 38% suspected, and 30% negative. A total of 26 of 37 (67%) sampling events collected inside and 18 of 40 (45%) collected at 5 meters were positive for H5N2. Sampling at distances from 70 meters to 1 kilometer resulted in about 2% positives and 58% suspected findings. The researchers found HPAI H5N2 viruses in particles up to 2.1 micrometer in diameter.
The authors conclude, "These findings demonstrate HPAI virus aerosolization from infected flocks, and that both the transport of infectious aerosolized particles and the deposition of particles on surfaces around infected premises represent a potential risk for the spread of HPAI."
September Avian Dis abstract
Ghana reports 3 H5N1 outbreaks in backyard poultry
Ghana reported three outbreaks of HPAI H5N1 in backyard poultry flocks that occurred last month, according to a new report from the World Organization for Animal Health (OIE).
Affected flocks ranged in size from 119 to 300 birds in locations in south Ghana, near the coast. The two chicken flocks in Greater Accra region were reported to be living in deep litter. The other flock, which was the smallest, comprised turkeys, chickens, and guinea fowl in Central region. The outbreaks began from Aug 13 to Aug 23.
All told, 179 poultry died from the disease and 440 were destroyed to prevent disease spread, for a total of 619 birds.
Sep 10 OIE report