LOS ANGELES/CHICAGO, May 2 (Reuters) - U.S. sellers of

raw milk appear undeterred by federal health warnings for

consumers to avoid drinking unpasteurized milk in light of a

bird flu outbreak that has affected dairy herds in nine states

and sickened at least one dairy farm worker.

Thirty of the 50 U.S. states permit the sale of raw milk,

which accounts for less than 1% percent of U.S. milk sales. A

nationwide survey of pasteurized milk - heated to kill pathogens

- found avian flu virus particles in about 20% of samples

tested.

Many raw milk drinkers share a deep skepticism of public

health officials, including the U.S. Food and Drug

Administration (FDA), which also battled political polarization

and misinformation during and after the COVID pandemic.

"Our consumers don't like the FDA. If the FDA says to do

something, they will do the opposite," said Mark McAfee, owner

of Raw Farm in Fresno, California, the largest U.S. raw milk

dairy.

Federal health officials have repeated warnings for

consumers to avoid raw milk, which can carry a host of

illness-causing pathogens, due to the outbreak. But changing the

minds of raw milk fans, who range from mothers seeking to feed

their families unprocessed food to body builders on

protein-heavy diets, will be an uphill climb.

Preliminary results of tests of pasteurized milk show that

the process kills the virus, leaving only remnants behind. But

the presence of H5N1 in milk has led many experts to warn

against consuming raw milk products as they investigate whether

bird flu can be transmitted by eating unpasteurized milk or

cheese. And there is evidence that the virus killed a large

number of cats that consumed raw milk on farms where the virus

was found.

Dr. Gigi Gronvall, an immunologist at the Johns Hopkins

Center for Health Security in Baltimore, said drinking raw milk

is already a "crapshoot" because of the risk of diseases such as

brucellosis, a bacterial infection that can be caused by

drinking raw milk.

"It's even riskier now. It's just not a good practice for so

many reasons," Gronvall said.

Enthusiasts have said raw milk has a creamier taste and

nutritional benefits that are wiped out by pasteurization. U.S.

health officials have said there is no scientific basis for the

health claims.

"Our sales have never been higher," said McAfee, without

providing figures.

His dairy has kept cows safe with precautions including not

moving cows on or off his farm and separating any sick cows from

the herd, McAfee said.

Nevertheless, products from Raw Farm and its predecessor

company, Organic Pastures Dairy, have been tied to outbreaks of

foodborne illness. Last year, the dairy recalled raw milk after

it was linked to a Salmonella outbreak that caused illness in at

least 19 people in California.

California has not reported avian flu in dairy cows.

Some former fans have stopped drinking raw milk, including

Connecticut farmer Jerry Grabarek, who in 2022 abandoned his

nearly 50-year habit of adding raw milk from his own cows to

coffee.

"You're playing Russian roulette with a lot of things when

you drink raw milk," Grabarek said.

'SMOKE AND MIRRORS'

Maryland-based raw cheese producer Sally Fallon Morell said

she doubts the accuracy of the federal government's findings and

believes the latest raw milk warnings are driven by worries that

the product is eroding pasteurized milk sales.

"It's all smoke and mirrors," said Fallon Morell, president

of the Weston A. Price Foundation, which advocates for raw milk.

Phoenix-based Sprouts Farmers Market ( SFM ) has more than

400 grocery stores and is the largest publicly held U.S. seller

of raw milk. Andronico's, which operates seven stores and is

part of the Albertsons Companies ( ACI ), carries a limited

assortment of raw milk local suppliers.

"We are coordinating with our suppliers and monitoring all

regulatory updates," Andronico's spokeswoman Sarah Holland said.

Sprouts did not immediately respond to a request for

comment.

This summer, Raw Farm will start national sales of frozen

raw milk labeled for pets, McAfee said. The company's fans are

already sharing social media posts about how they buy pet

products to get around laws that limit raw milk sales for human

consumption.

A Texas farm worker developed conjunctivitis following

exposure to dairy cows - the second case of the H5N1 strain of

bird flu identified in a person in the United States, following

a 2022 case in Colorado.