Abstract
There is limited information on the persistence of HPAI H5N1 in small farm settings. In 2023, we investigated the persistence of avian influenza H5N1 in the environment of an infected 6550-bird pheasant farm that had been depopulated, cleaned, disinfected, and placed on a mandatory 120-day USDA fallow period. The farm contained two flocks of Manchurian and Chinese ring-necked varieties. The outbreak occurred in the Chinese ring-necked flock totaling 3275 birds separated into four flight pens. The four flocks were designated as a concentrated infected flock, infected (non-concentrated) #1, infected (non-concentrated) #2, and a concentrated non-clinical flock. The flocks were sampled weekly until all flocks were negative for four sequential sampling periods. Samples taken from each pen were pooled feeders, waterers, boot covers, and high-touch surfaces. Sampling was from April 18 to June 20; it took only 70 days to observe four consecutive negative test results for avian influenza virus. Positive samples were typed for H5 and H7 followed by virus isolation and sequencing. Only one of the six positive H5 samples was virus-isolation-positive (boot covers in the concentrated infected flock). Ambient temperatures during the sampling period ranged from 43-88 degrees F. This preliminary study shows that the 120-day fallow period may be too long and can be shortened to allow earlier restocking, additional sample collection is important from a diagnostic point of view and the positive boot covers emphasize the importance of footwear in biosecurity and surveillance plans. Additional research is warranted under varying environmental and outbreak conditions.
Co-Author(s)
Carol Cardona, University of Minnesota, Justin Brown, Pennsylvania State University, Evan Wills, New York State Department of Environmental Conservation, Kaitlyn St Charles, University of Minnesota, Krysten Schuler, Cornell University
Abstract Category
Biosecurity, mitigation, control, and post-epidemic considerations in poultry