California's state veterinarian in a January 7 statement announced a ban on all poultry and cattle exhibitions until further notice as part of the state's efforts to curb the spread of H5N1 avian flu to people and to uninfected animals.

The virus has become widespread in dairy cows, as well as in commercial and backyard poultry, and Governor Gavin Newsome on December 18 declared a state of emergency to free up more resources to battle the virus.

Annette Jones, DVM, state veterinarian, said, "We will continue to assess the threat over the next few months and rescind this ban if the situation changes."

More detections in poultry and cattle, more wild-bird warnings

In other developments, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed 4 more H5N1 detections in dairy cattle, 3 in California and apparently 1 in Michigan that the state first announced in October 2024. The new confirmations push the national total to 923 and California's total to 706. 

APHIS also confirmed one more H5N1 outbreak in poultry, which involves a layer farm in Ohio's Darke County that has 245,300 birds.

Separately, the Michigan Department of Agriculture and Rural Development today reported highly pathogenic avian flu in a backyard flock in Oakland County, which includes the Detroit metro area.

Meanwhile, Arizona Game and Fish yesterday urged hunters and falconers to take steps to avoid and prevent the spread of the virus, given recent detections in the state's domestic poultry and wild birds. It said dabbling duck species that carry the virus rarely show illness signs, but Canada geese, eagles, other raptors, and domestic poultry appear to be susceptible to more severe clinical disease. 

Iceland's Food and Veterinary Authority (MAST) this week announced that highly pathogenic H5N5 avian influenza has been found during the autopsy of a kitten that died, according to a statement translated and posted by Avian Flu Diary, an infectious disease news blog. 

Officials said the 10-week-old kitten died on December 22, shortly after two cats from the same litter died but were not tested. Other littermates had left the home before the other cats were sick and remain asymptomatic.

The kittens are from Ísafjörður in the Westfjords region of northwest Iceland, but the one diagnosed as having H5N5 had arrived in Reykjavík, the country's capital.

MAST said the same H5N5 strain had been detected in Iceland's wild birds in September 2024 and in poultry in December 2024. It added that the cats likely contracted the virus from wild birds.

A separate report to the World Organization for Animal Health (WOAH) said the kittens' main clinical signs were lethargy, loss of appetite, cramps, and stiffness.

H5N5 expands geographic range, including Greenland

The most recent quarterly overview of avian flu from the European Centres for Disease Prevention and Control (ECDC) and the European Food Safety Agency (ESFA) said H5N5 viruses continue to expand their geographic and species range, with spillovers to domestic birds reported in Iceland, Norway, and the United Kingdom.

In a new related development, animal health officials in Greenland reported highly pathogenic H5N5 in a northern fulmar, a sea bird, found dead in October in the northwest, according to notification today from WOAH.

Yesterday the Centers for Disease Control and Prevention (CDC) declared its investigation into the Salmonella outbreak linked to cucumbers over after 113 cases and 28 hospitalizations had been identified. 

Also, the Food and Drug Administration (FDA) declared its investigation into an outbreak of Escherichia coli O157:H7 infections traced to romaine lettuce over after 88 cases have been reported. 

The FDA has not identified the lettuce supplier in that outbreak, according to Food Safety News (FSN). 

The FDA also announced an end to another prove into a separate 26-case E coli O157:H7 outbreak without identifying a source of the pathogen, FSN noted.

13 new cases linked to cucumbers 

In the outbreak linked to cucumbers, the CDC said 13 new cases and 3 new hospitalizations had been noted since an update on December 19. 

Both fresh whole and sliced cucumber from Mexico were recalled in this outbreak. In total 23 states reported cases, and there were no deaths. The CDC found seven clusters of illnesses in this outbreak, including three assisted living facilities, three school districts, and one restaurant. 

Illness-onset dates range from October 12 to December 7, 2024. The age of patients varied from less than 1 to 98 years, with a median age of 30, and 60% were women.

The true number of sick people in this outbreak was likely much higher than the number reported, and the outbreak may not have been limited to the states with known illnesses

"The true number of sick people in this outbreak was likely much higher than the number reported, and the outbreak may not have been limited to the states with known illnesses," the CDC said. "This is because many people recover without medical care and are not tested for Salmonella."

Chronic wasting disease (CWD) has been detected in a wild deer in Chippewa County, Wisconsin, for the first time, prompting the renewal of baiting and feeding bans in two counties.

The Wisconsin Department of Natural Resources (DNR) reported the positive case of the fatal neurodegenerative disease yesterday in a 1-year-old buck harvested by a hunter within 10 miles of the Barron and Dunn county borders.

In accordance with state law, Chippewa County will renew its 3-year deer baiting and feeding ban, and Barron County will renew its 2-year baiting and feeding bans. Dunn County already has a 3-year baiting and feeding ban and thus will be unaffected by the finding.

"Baiting or feeding deer encourages them to congregate unnaturally around a shared food source where infected deer can spread CWD through direct contact with healthy deer or indirectly by leaving behind infectious prions in their saliva, blood, feces and urine," the DNR wrote.

First Wisconsin cases identified in 2002

The Wisconsin DNR has been tracking the state's wild white-tailed deer population for CWD since 1999, with the first cases identified in 2002.

Baiting or feeding deer encourages them to congregate unnaturally around a shared food source where infected deer can spread CWD through direct contact with healthy deer or indirectly by leaving behind infectious prions in their saliva, blood, feces and urine.

CWD is caused by infectious misfolded proteins called prions, which spread among cervids such as deer, elk, and moose. The disease isn't known to infect humans, but some experts fear it could cause illness similar to another prion disease: bovine spongiform encephalopathy ("mad cow" disease). The Centers for Disease Control and Prevention warns against eating meat from infected animals.