Highly pathogenic avian influenza has been confirmed in a pig at a small farm in Crook County, Ore., in the first instance of the virus infecting pigs in the U.S.

A necropsy confirmed the infection in a full-size pig from the farm.

Preliminary results from a nasal swab also indicated a “teacup” pig housed in a chicken coop tested positive for the virus. Confirmation through a necropsy is expected from a laboratory in early November.

Bird flu also infected a backyard flock at the property, according to the Oregon Department of Agriculture.

During a news conference Oct. 30, experts expressed concern about the development, as pigs are susceptible to viruses from both birds and humans, which could cause intermingling and mutations of the disease.

“We do worry about changes in this virus,” said Dr. Dean Sidelinger, state epidemiologist.

Monitoring hasn’t indicated HPAI is becoming more easily spread or that it is causing more serious illness among humans, he added.

The U.S. Centers for Disease Control has confirmed 36 instances of HPAI in humans, all of whom had close contact with infected animals, Sidelinger said.

Oregon has had 41 outbreaks that affected 907,000 birds and resulted in about 130 people being exposed to avian influenza, but there have been zero human infections.

“The risk to the public remains low,” Sidelinger said.

Incident details

Five pigs and 70 birds in a backyard flock, including chickens, ducks and geese, have been euthanized at the Crook County property to prevent the spread of the highly contagious virus, according to the ODA.

The USDA lists 180 birds as being affected in that case, confirmed Oct. 25 after birds died on the farm.

ODA arrived at the property the day it was reported and discovered pigs also had been exposed to the virus.

Dr. Ryan Scholz, state veterinarian, said animals on the property were exposed to wild waterfowl.

A quarantine has been placed on the property and ODA’s veterinary team is conducting surveillance.

The agency has provided the animal owners with personal protective equipment and the Oregon Health Authority and Crook County Public Health are educating and monitoring exposed individuals.

Upticks in cases in the West are linked to wild bird migration patterns.

A commercial egg producer in Clackamas County, Ore., had 150,000 birds impacted in an outbreak confirmed Oct. 24.

HPAI also was confirmed Nov. 1 in a backyard flock of geese and chickens in Jackson County and 40 birds were affected. This is the first instance of the virus in backyard or commercial flocks in Jackson County.

In Washington on Nov. 1, 110 birds in a backyard flock were affected by HPAI in Stevens County and 20 birds were euthanized from a backyard flock in Okanogan County.

Between Oct. 29 and Nov. 2 in California, 731,800 birds were euthanized from four outbreaks at commercial broiler facilities, as well as another 48,300 turkeys at a commercial farm.

Food remains safe

None of the animals on the Crook County farm entered the food supply chain nor were they intended for the commercial food market.

When food is properly prepared and cooked, avian influenza does not affect meat or egg products.

The U.S. Centers for Disease Control also recommends choosing pasteurized milk and dairy products for safety.

“People do not need to be concerned about the food they buy in the grocery store,” Sidelinger said.

Spread to other animals

The current strain of avian influenza circulating in the U.S. and across the globe is endemic in wild birds, causing outbreaks in poultry, wild mammals, including seals and sea lions, and domestic animals, including dairy cows.

Bird flu has been confirmed in dairy cattle in 14 states, including California and Idaho.

Oregon had no confirmed cases of avian influenza in dairy cattle as of Oct. 30.

Cats at dairy farms have become sick, potentially from drinking unpasteurized milk from infected cows or from eating infected birds, Sidelinger said.

More bird flu coverage

WSDA: Migratory birds spreading avian influenza

Bird flu infects four Washington farmworkers

Bird flu strikes Eastern Washington chicken farm

Slow recovery: A dairy farmer talks about impact bird flu had on his herd

USDA approves field study of bird flu vaccine for cattle

Bird flu blues: Highly pathogenic avian influenza hits dairy herds without warning

Biosecurity measures

Ag producers can limit the spread of HPAI through biosecurity measures, including:

•Preventing exposure of domestic poultry and livestock to wildlife, especially wild waterfowl.

•Limiting the commingling of different species of livestock, especially poultry and pigs.

•Washing hands before and after handling their flock.

•Changing clothes upon contact with birds.

•Cleaning vehicles, tools or equipment.

•Sanitizing shoes in clean foot baths.