Why health experts are so worried about raw milk

(NEXSTAR) – As the H5N1 avian influenza virus continues to spread among an unknown number of dairy cows, health experts are telling the public that milk and other dairy products are still safe to consume, with one major exception.

When cows are infected with avian flu, the virus can be found in large amounts in their milk, but pasteurization kills or inactivates the virus, according to the Food and Drug Administration.

Raw milk, on the other hand, is not pasteurized. “Raw milk may be contaminated with harmful bacteria that can cause serious illness,” the CDC says on its website.

It is not yet known whether the live virus can infect people who ingest unpasteurized milk, but there are records of people getting sick from eating contaminated chicken that was not thoroughly cooked.

“We have very real concerns about the safety of raw milk because raw milk and raw dairy products may not have undergone the same processing to inactivate the virus,” said Megan Davis, an associate professor at the Johns Hopkins Bloomberg School of Public Health.

Davis said there was also evidence that animals could become ill from consuming raw milk: “We’ve seen on dairy farms that cats on farms who have consumed raw milk have developed neurological and respiratory diseases and higher mortality rates.”

Besides the avian flu concerns, raw milk may contain Salmonella, E. coli and Listeria, according to the FDA.

But raw milk sales are on the rise: From mid-March (when the avian flu virus was first identified in U.S. cows) through mid-May, weekly raw milk sales increased 21% to 65% compared with the same period a year ago, according to market research firm Nielsen IQ.

Mark McAfee, owner of Law Firm USA in Fresno, California, said he can’t keep unpasteurized product in stock.

“People are asking for raw milk like crazy,” he said, noting that no avian flu has been detected in his herd or in California. “Everything the FDA tells their customers to do, they do the opposite.”

The surge surprised Donald Schaffner, a food science professor at Rutgers University, who called the trend “absolutely surprising.”

“Food safety experts like me can only shake our heads,” he said.

Before the milk standard was adopted in 1924, about 25 percent of food-borne illnesses in the U.S. were linked to consumption of dairy products, said Alex O’Brien, safety and quality coordinator at the Dairy Research Center. Today, food-borne illnesses caused by dairy products account for about 1 percent of such illnesses, he said.

“Drinking raw milk is like playing Russian roulette,” O’Brien said, adding that the more often you consume raw milk, the greater your chances of getting sick.

The Associated Press contributed to this report.