Health officials urge Americans to beware of quintessential summer pastime this year

Americans venturing to state fairs next month should be on high alert for bird flu, health experts warn.

Popular petting zoos and popular milking demonstrations pose a high transmission risk for a virus that is becoming more risky for humans. 

Fourteen Americans have been infected with the H5N1 strain this year and the White House is bankrolling efforts to trial human vaccines for avian flu in cases transmission becomes more widespread. 

All of this year's cases had contact with dairy cows or poultry, both of which are mainstays at state and county fairs.  

Fair organizers nationwide have undertaken precautionary measures to keep revelers safe, mostly by limiting people’s access to cows. They'll do so by keeping people away from lactating cows and bar spectators from milking them. 

Visitors will note some big changes this summer.

Minnesota, for instance, will not include cows and calves in their Miracle of Birth exhibit at the state fair. 

And cows being shown at Missouri fairs will need to have proof of a negative flu test.

Hundreds of state and county fairs will take place nationwide over the next couple of months, with thousands of Americans petting goats, touring barns, milking cows, and watching animals give birth.

Dr Andrew Bowman, a veterinary professor at Ohio State University, said: ‘What we do at fairs kind of violates every tenet of biosecurity that we preach, and we do it on public display, and we charge the public.

‘As great as fairs are for agricultural education, they create situations with multiple species from different farms housed in one spot.’

The CDC has confirmed 14 cases of avian flu in farmers who work with poultry and dairy cattle since 2022, with Colorado now seeing nine cases.

The public health body has launched an online tracking dashboard based on surveillance of wastewater samples.

The dashboard draws on samples of wastewater that test positive for A-type flu viruses — like the H5N1 strain infecting cattle on US dairy farms. The data is presented in map form and compares positive tests to the same time last year to look for upticks.

The University of Minnesota Extension, a public health education service, published guidance for fairs with cow exhibits last week. 

It recommends that lactating cattle not attend fairs through the end of 2024, as raw milk contains high concentrations of bird flu virus.

And fans of Minnesota’s Miracle of Birth Center, where visitors can watch cows and other livestock give birth, will not include cows this year.

The fair will continue to show mother cow-calf pairs, but the mother cows will not be lactating, and the calves will be weaned.

A growing number of state and county fairs also have vets on staff to check evidence that the cows entering fairgrounds have tested negative for the flu.

Wisconsin’s veterinary superintendent, Dr. Tia Kastenson, said: ‘They’ll collect the papers, make sure all the lactating cows have their (test) dates in check, and then they’re going to monitor them as those cows come off the trailer.

‘If there’s anything questionable, they’re gonna pull (the cows) before they go into the barn.’

Farmers bringing their lactating dairy cows to the Missouri State Fair next month will need to have the animal’s milk tested for H5N1 no more than a week before their arrival. Those who arrive at the fair with milking cows that have not been tested will be turned away.

The fair organizers have also chosen to close the area where spectators can milk cows themselves.

Missouri State Veterinarian Dr Steve Strubberg said: “Once [avian flu is] in a cow, it spreads to herd mates through the milking process.

‘For that reason, the State Fair Commission is not going to allow the normal exhibitors to utilize the parlor to where they would use the same equipment, from one cow and one herd to the next.’

The risk of contracting bird flu to the ordinary non-farmer is low thanks to the power of pasteurization, which kills off bacteria and viruses in milk before it goes to stores.

According to the USDA: ‘At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health.’

The CDC announced a $10 million push on Tuesday to help curb the spread of avian flu among farm workers, including millions allocated to getting them vaccinated for a range of flu strains, including the avian flu.

CDC's principal director Nirav Shah said: ‘Preventing seasonal influenza for these workers, many of whom are also exposed to bird flu, may reduce risks of new strains of influenza emerging.’