By Lisa Schnirring
The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) today confirmed H5N1 avian flu detections in Nevada dairy herds the state's first since December along with several more detections in US poultry flocks.
In other developments, European health officials shared more details about the latest UK case, including genetic details, and North Dakota wildlife officials are monitoring a Canada goose die-off along the Missouri River in the central part of the state.
Targeted starling removal a critical step
Nevada reported its first H5N1 detection in dairy cows in early December 2024, which affected a herd in Nye County, located northwest of Las Vegas.
In two recent statements, the Nevada Department of Agriculture (NDA) said the virus had been detected in dairy cattle in Churchill County, which borders Nye County to the northwest. Officials said they, along with USDA wildlife services, are taking additional actions to prevent the spread of avian flu. Dairy cattle in both of the counties have been placed in quarantine, and the USDA investigators begin surveillance and testing wildlife to better determine which strains are circulating and how the virus is spreading.
Federal and state groups will also begin removing non-native European starling populations in Churchill, Pershing, and Lyon counties. The NDA called the starling removal a "critical step" and that due to their large numbers, the birds are a nuisance population that can spread disease and contaminate animals' food and water sources.
In a 2024 Facebook post, the Nevada Department of Wildlife said several thousand birds from the species typically migrate through northern Nevada in the winter on their way south. It added that the European starlings are aggressive and outcompete native birds for nesting sites and can spread disease to livestock.
NDA Director J.J. Goicoechea, DVM, said in a January 31 statement, "The challenge with this virus is that it may be spread through contaminated clothing worn and equipment shared between animals, but birds carrying the disease can also infect domestic animals and livestock."
The NDA has already been conducting testing at milk silos as part of the National Milk Testing Strategy to detect the virus before cows on dairy farms show symptoms.
Alongside the 4 new H5N1 confirmations in Nevada dairy herds, APHIS also reported 1 more detection in a California herd, raising the national total to 956 and California's total to 735.
More poultry outbreaks, deaths in North Dakota geese
On the poultry front, APHIS also confirmed more H5N1 detections in at least seven states, including commercial farms in Missouri (turkeys and broilers) and Ohio (turkeys and layers).
More detections in backyard birds were reported in Maryland, Virginia, Florida, California, and Nebraska.
Separately, the Iowa Department of Agriculture and Land Stewardship yesterday reported an outbreak at a layer farm in O'Brien County, the state’s second outbreak of the year. The findings await final confirmation from APHIS.
And the North Dakota Game and Fish Department on January 31 announced it is monitoring a die-off of Canada geese along the Missouri River and Nelson Lake in Oliver County. Tests on carcasses show highly pathogenic avian flu as the likely cause.
Recent UK patient had mild symptoms
In its latest communicable disease update, the European Centre for Disease Prevention and Control (ECDC) fleshed out more details on the United Kingdom's recent human case.
It said the patient, following prolonged contact with infected poultry on a farm, had mild respiratory symptoms and irritated eyes. One symptomatic household member tested negative, and health officials are tracing contacts and offering antiviral medication to those at high risk.
Genetic sequencing revealed the virus belongs to the DI.2 genotype, which is circulating in UK birds this season and is distinct from genotypes circulating in the United States. Further sequencing revealed the hemagglutinin (HA) segment is nearly identical to a strain collected in the middle of January from a UK chicken.
The polymerase basic protein 2 (PB2) gene has the I292V mutation, which has been linked to increased polymerase activity in tests with mammalian cells and increased virulence in mice. However, the ECDC said the mutation is very common in strains isolated from birds.
Source : umn.edu