Tennessee health officials have given a raw-milk cow-share operation that has been linked to an E. coli O157 outbreak that has sickened 9 children — all of them under 7 years old — the green light to start offering its milk to its cow-share members again. “We will be delivering milk today,” dairy farmer Marcie McBee, owner of McBee Dairy Farm near Knoxville, wrote in an e-mail to Food Safety News on Friday morning. Raw milk is milk that hasn’t been pasteurized to kill harmful foodborne pathogens such as E. coli, Campylobacter, Salmonella, and Listeria. Often referred to as legal loophole in states where raw-milk sales are illegal, cow shares, or herd shares, allow consumers to buy a share of a cow (or other dairy animals such as goats). By doing this, a portion of the milk from the animal is theirs, which means they aren’t technically buying milk from the farm where the cow shares operate. In giving the farm the green light, health officials said that the outbreak, which likely began in early October, is over since no new cases have been reported.  In light of this, coupled with the fact that the most recent raw-milk testing indicated that the milk was not contaminated — at least at the time the samples were collected — the state has lifted the cease-and-desist order. One of the provisions of lifting the order was that the dairy must work with University of Tenneessee Agriculture Extension Office’s food safety expert, Faith Critzer, in dairy-farm best practices. McBee said that she has agreed to do that. Critzer said that the dairy was operating as a typical dairy, with some good safeguards in place, but that she was able to supply McBee with some additional strategies that could improve the dairy’s safeguards. The dairy’s website describes raw milk as “real milk” that hasn’t been pasteurized, homogenized, and contains no additives, hormones or antibiotics. “Real milk — the way God intended it,” it reads. According to a Nov. 8 press release from the Knox County Health Department and the state’s eastern regional Health Department office, three of the infected children developed Hemolytic Uremic Syndrome (HUS), a complication of a potentially fatal strain of E. coli that can lead to kidney failure and other serious health problems. However, due to patient-confidentiality laws, no information about the condition of the children can be made available. The state’s press release also said that even though several raw milk samples, including the most recently collected samples have been negative for E. coli O157, one raw-milk sample obtained from a consumer and several manure samples collected from the farm revealed the presence of DNA for the toxin produced by E. coli O157 that causes HUS. “We are pleased that the most recent raw milk sample tested negative but not surprised,” said Knox County Health Department Director Dr. Martha Buchanan.“Typically in an investigation we’re collecting samples several days or weeks after the product that made people sick was produced.” For that reason, she said, while lab results are important, they are often negative and are only one part of an investigation.” Referring specifically to the McBee Farm, which before it began producing raw milk was a Grade A dairy, the state’s press release says that the investigation has not identified any specific problem with the McBee Dairy farm. Even so, in referring to the close proximity of a cow’s udder to the source of manure, which can be contaminated with fecal bacteria, Buchanan said that milk can easily be contaminated. “It’s  just the nature of the raw milk industry,” she said. “Even with safety precautions in place at the dairy, there is no way to guarantee that raw milk is safe for consumption.” Even in states such as California and Washington state, where raw-milk dairies must meet high sanitation standards and be inspected and have their milk tested on a regular basis, E. coli outbreaks have led to recalls of some dairies’ raw milk. Tennessee Deputy State Epidemiologist John Dunn told Food Safety News that it appears that the contamination of the milk at the McBee farm happened at a specific point in time and the supply has not been continuously contaminated. What about the link to the farm? “We feel we’ve identified the source,” Dunn said, pointing out that all of the children who became ill drank raw milk from the dairy. “It’s a pretty clear signal about the source,” he said. “The data and exposure information is very compelling.” And while people are encouraged “to know their farmer,” Dunn said that even though you can know your farmer, you can’t know if there are pathogens in their animals’ milk. He also pointed out that while people say they should have the right to drink and eat what they want, when it comes to children — who are more vulnerable to foodborne illnesses — people should take this vulnerability into account. “As we see a resurgence of raw milk consumption, we’re all seeing a resurgence of diseases caused by raw milk,” he said. In the world of food safety, the term “epidemiological evidence” refers to patterns of illnesses, such as food-poisoning outbreaks, that are associated with a common source, such as lettuce, milk or hamburger, often from a specific farm, company or processor. Pathogens cause outbreaks often can’t be found in the food, on the farm, or in the processing facility, because by the time foodborne illness symptoms begin, are diagnosed and lab-confirmed, the suspect food is no longer available to be tested. This is particularly true for food poisoning outbreaks involving fresh produce or milk. Then, too, with E. coli, for example, a cow can be harboring the pathogen one week and not the next. “In the vast majority of foodborne illness outbreaks, the pathogen is never found in the food product or the environment,” said food safety attorney Bill Marler, publisher of Food Safety News. But epidemiological evidence — the statistical analysis of what common food the sick people were exposed to — is valid not only in the public-health arena but also in the court of law. In cases where the outbreak pathogen is not detected in a particular food, Marler says investigators “step back and let the facts speak for themselves. The legal question becomes ‘What is the most likely cause of the outbreak?'” Marler said it’s not at all uncommon for the weight of the epidemiologic evidence to prove the case in legal actions involving foodborne illnesses. For example: In 2009, Nestlé Toll House prepackaged cookie dough sickened 77 people in 30 states. Of those, 35 were admitted to the hospital, a few with severe illness. Nestlé responded to the outbreak by recalling 3.6 million packages of its popular chocolate chip batter. Even though the pathogen was never found in any of the leftover cookie dough or in the processing plant, the epidemiological evidence pointed to the product as the source of the outbreak and illnesses. Marler said Nestlé paid settlements to the victims, based on the epidemiological evidence that linked all of the sick people to presumably contaminated raw cookie dough. Effects on McBee’s customers On Nov. 8, McBee told Food Safety News that the dairy has lost four customers — two of whom did not want to “worry about their children getting sick.” She also has two other customers who are trying to decide what they want to do. But demand for the dairy’s raw milk remains strong, nonetheless. “We have a waiting list of 15 families at this time,” she said.