A government investigation has tied raw milk consumption to a 2008 outbreak of Escherichia coli in Connecticut, which landed five people in the hospital.
It also puts a price tag on the outbreak: $413,402. And it hints the infection spread beyond those who drank the allegedly tainted milk.
The report, published in Clinical Infectious Diseases, is the latest to warn against raw or unpasteurised milk, which experts say is becoming increasingly popular in the US.
"There has been a movement away from highly processed foods to organic foods," said Bill Marler, a Seattle-based lawyer who represented three of the sickened people in Connecticut. He recently settled the cases with the Simsbury farm that made the milk and the grocery store that sold it, but would not give the amount of the settlement.
Sites that talk about raw milk
"There are so many internet sites out there that talk about raw milk as if it cured everything from autism to erectile dysfunction," said Marler.
One such site is run by Randolph Jonsson, a raw milk proponent who was not involved in the Connecticut outbreak.
"Milk straight from the udder, a sort of 'stem cell' of foods, was used as medicine to treat, and frequently cure some serious chronic diseases," he notes on his website.
But researchers say there is scant support for such health claims, and that the risks are much clearer.
No health benefits
"There are no health benefits from drinking raw milk that cannot be obtained from drinking pasteurised milk that is free of disease-causing bacteria," said Hannah Gould, of the Centres for Disease Control and Prevention in Atlanta. "Pasteurisation can decrease the activity of some vitamins, including thiamine, vitamin B12, and vitamin C, but milk is a relatively minor source of these vitamins."
"Less than 1% of the dairy products consumed in the US are unpasteurised, yet more than 50% of dairy-associated outbreaks are linked to unpasteurised products," said Gould, who was not involved in the new investigation.
From 1993 to 2006, she added, outbreaks related to raw milk, and cheese and yogurt made from it, have been tied to 1,571 illnesses, 202 hospitalisations and two deaths.
In the new study of the 2008 cases, Dr Alice Guh, also at the CDC, and colleagues identified seven cases of confirmed E. coli infection, either via lab tests for a toxic strain - E. coli O157:NM - or via diagnosis of hemolytic uremic syndrome.
Five people ended up at the hospital. Although none died, they racked up an average medical bill of almost $73,000 each.
All had diarrhoea, and one adult had thrombotic thrombocytopenic purpura. Three kids had hemolytic uremic syndrome, which destroys red blood cells and causes short-term kidney failure.
"Children represent one of the population groups at highest risk for experiencing severe illness," Guh said.
No lack of hygiene
She said the farm had "acceptable milking and sanitation procedures," demonstrating that the contamination wasn't due to a lack of hygiene.
"You can absolutely do the best you can in producing raw milk, but because of the location of the cow's anus to the cow's udder, it makes it really difficult for the bacteria not to get into the milk," said Marler. "You can't tell a cow not to poop when it gets milked."
Five of the people with confirmed infections had consumed raw milk from the same dairy farm in Simsbury, Connecticut. Two others, a pair of toddlers, had been playing with a kid who also had drunk the milk.
"My concern is that some consumers are not fully aware of the risks and may be misled by unsupported claims," said Dennis D'Amico, a researcher at the Vermont Institute for Artisan Cheese at the University of Vermont in Burlington.
Disease-causing bacteria in raw milk
He said several kinds of disease-causing bacteria may be found in raw milk, most commonly Campylobacter jejuni - the usual suspect in food poisoning.
Even in milk with very low levels of bacteria overall, he added in an e-mail, he'd isolated toxic strains of E. coli.
"Despite all our knowledge and best efforts there is no way to be certain that raw, unprocessed milk will be completely free of pathogenic microorganisms," he explained.
"If raw milk safety could be guaranteed at least to the level of pasteurised milk I would opt for the former. Unfortunately the risks far outweigh the benefits."
Sales has been banned
Raw milk sale between states has been banned for decades, but 10 states currently allow retail sale, according to Marler.
He recommends that consumers visit http://www.realrawmilkfacts.com, a website developed by university and government scientists, for more information.
"A lot of states do have a variety of requirements, but it is a real hodgepodge of rules and regulations," he said. "There are really no particular standards or testing protocols."
He said raw cow milk usually costs at least twice as much as pasteurised milk in the store, while raw goat milk may run as high as 18 dollars per gallon.
"People are even touting raw goat milk as an alternative to mother's milk," he said. "It's a real concern." (Reuters Health/ November 2010)
Drink milk and lose more weight
Allergic children may tolerate warm milk
Main food-poisoning culprits