WASHINGTON, D.C. – The first cases of humans catching flu from pigs in the U.S. this year both came from Michigan.

The Centers for Disease Control and Prevention (CDC) is linking each of the cases to county fairs in Oakland and Tuscola counties.

According to the CDC, one of the cases involved a child who was a fair exhibitor exposed to infected pigs within 10 days of developing symptoms.

Both people were recovering at home after given anti-viral drugs to treat the influenza.

A human flu infection from a pig is rare but not uncommon, according to the CDC. In 2022, Michigan had at least one person come down with flu linked to contact with an infected pig during a fair in Berrien County.

There were at least nine other confirmed flu transmissions from pigs to humans last year in other states, including Ohio, Wisconsin, West Virginia and Georgia.

Indiana has not had a confirmed case of flu spreading from pig to human since an outbreak blamed on exposure during county fairs in 2012, said Denise Derrer-Spears, a spokesperson for the Indiana State Board of Animal Health.

Derrer-Spears said she wasn’t sure why there have been no confirmed cases since then, but state guidelines to minimize the chances of flu spreading from pigs to humans and from humans to pigs were distributed to operators of county fairs statewide following the outbreak.

She said transmission of flu between the species primarily happens at county fairs or pig shows because the animals come from all over and are kept in pens closer to each other than a farm.

Like humans, she said flu in pigs is spread from contact with airborne particles emitted from sneezing and coughing. Humans can then become infected by touching a pen or whatever else they come into contact with touched by the airborne particles.

“That makes that transmission of that virus fairly easy to happen especially when there’s a lot of it in a very small space,” she said.

The state guidelines for preventing infection include pigs at county fairs or shows not staying in a barn for more than 72 hours to keep any build-up of the virus in closed quarters from becoming larger.

Among the other recommendations are washing hands after having contact with a pig and not eating or drinking close to the animals because of the risk of airborne particles from their sneezing and coughing landing on food and beverages.

“We tell exhibitors and visitors if they’re sick stay out of the barn. If an animal is sick, leave it home or gets sick at the fair, get it out of there,” Derrer-Spears said.

She said another reason human flu infection from pigs is highest at fairs and other related events is because of heavy foot traffic restricted, typically, to just family members and workers at farms.

According to the CDC, the symptoms of contracting flu from pigs are similar to catching the virus from humans. The symptoms are usually mild but can become severe depending on the health or age of the individual.

“Like seasonal flu, some groups of people are at higher risk of developing serious complications from infections with swine flu viruses,” CDC officials said.