Low pathogenic avian influenza (LPAI) has been confirmed in a flock of almost 9,500 breeding ducks in Monterey County, California.
The virus, which is of the H5 serotype, was found as the result of routine surveillance, according to the U.S. Department for Agriculture (USDA), and no birds had shown signs of disease. The source of the virus is unknown, but it was subsequently found to be similar to one found in North American wild birds.
Two neighboring poultry premises in the county have been quarantined. Samples from those two farms have been taken, and the results are pending. Movement controls and enhanced surveillance are being applied, and the affected premises have been disinfected.
USDA, which reported the outbreak to the World Organisation for Animal Health (OIE) on April 24, is not linking these latest cases to the detection of an H7N3 LPAI virus at five locations in Stanislaus County, California, in September and October of 2018.
During 2018, LPAI viruses of the H7N1 subtype were detected as the result of routine surveillance in a broiler breeder flock in Texas, and at a turkey farm in Missouri, and an H5N2 LPAI virus was found at eight turkey farms in Minnesota in October and November 2018. In all of these cases, however, the disease situation was thought to be resolved.
California still confirming virulent Newcastle disease cases
While animal health officials in California now have a case of avian flu to contend with, they also continue to deal with new cases of virulent Newcastle disease (vND).
According to a press release from the USDA Animal and Plant Health Inspection Service (APHIS), three additional cases of vND were confirmed in Riverside and San Bernardino counties during the week of April 19-25. All three cases were in backyard exhibition chickens.
The three new cases bring the total number of confirmed vND cases in California in 2019 to 425. There has also been one case in Arizona and one case in Utah this year.
Earlier this month, Monterey Herald reported that Monterey County Fair had cancelled its poultry shows because of an outbreak of vND in California.