BOSTON – At Whittier Farms dairy, the fifth-generation owners brag of the quality of their Holstein cows and still deliver milk right to your door, in glass bottles. Customers like the products because they are a hormone-free taste of old New England.
But health officials now say three elderly men have died and at least one pregnant woman has miscarried since last June after drinking bacteria-contaminated milk from the dairy's plant in Shrewsbury, about 35 miles west of Boston.
All were infected with listeria, which is extremely rare in pasteurized milk. It is more often found in raw foods, such as uncooked meat and vegetables, and processed foods such as soft cheeses and cold cuts.
The outbreak is believed to be only the third time listeria has ever been linked to pasteurized milk in the United States, said Dr. Alfred DeMaria, state director of communicable disease control.
"We know something is going on; we just don't know what it is," DeMaria said. "We just need to find out how the bacteria is getting into the milk."
Listeria bacteria are often present in manure and are commonly found in soil and water. Pasteurization is supposed to kill listeria.
Tests at the Whittier Farms plant found nothing wrong with its pasteurization process, deepening the mystery.
Health investigators are now looking at the cooling and bottling machinery, including the connecting pipes, for the source of the bacteria, DeMaria said. Investigators have taken about 70 samples from vents, ceilings, floors, tanks, bottle-washers, bottles and other equipment.
"We're focusing on every inch of contact with the milk products," DeMaria said.
The dairy, which distributes milk under various brand names to homes and stores across central Massachusetts and also operates a 500-acre farm in the town of Sutton, has suspended operations until the source of the contamination is pinpointed.
The Whittier family has declined to be interviewed. In a statement posted in the window of its dairy store and in a letter to its customers, the farm said it is "extremely concerned about the situation" and is cooperating with the investigation.
Health officials say about 2,500 serious listeriosis cases are reported in the United States every year, 20 to 40 of them in Massachusetts. Symptoms include fever, nausea and diarrhea.
Listeria can cause serious illness or death in pregnant women, newborns, the elderly and patients with compromised immune systems. Healthy adults and children generally recover.
A 1983 outbreak in Boston that was believed to have been caused by pasteurized milk led to 14 deaths.
In the Whittier Farms outbreak, DNA testing on the four patients showed they carried exactly the same strain of listeria, suggesting the germ had a common source. After the test results came back in mid-December, health officials began interviewing the patients and their families, hoping to zero in on the source.
At about the same time, a health worker at the hospital where an 88-year-old man was diagnosed with listeriosis learned that the man had had unpasteurized cider and coffee-flavored pasteurized milk. When both drinks were tested, only the pasteurized milk — from Whittier Farms — came back positive.
Officials then found listeria in an unopened container at the dairy's store in Shrewsbury.
State health officials would not identify any of the listeria patients because of privacy laws. But health officials in the town of Medway confirmed that the 88-year-old man who died Jan. 3 was John J. Powers, a World War II veteran and retired timekeeper at the Boston Naval Shipyard.
Powers' son bought the milk. The younger Powers had some flu-like symptoms for several days but recovered, while his father — who had other health problems — became ill and died, said Bill Fisher, Medway's health agent.
Two of the victims, a 78-year-old man and a 75-year-old man, died in Worcester County in June and October.
A pregnant, 34-year-old woman recovered but suffered a miscarriage. Health officials suspect another pregnant woman, 31, contracted listeriosis from Whittier Farms milk. She recovered, and her baby is doing fine.
Brian Gay, owner of Maple Farm Dairy, has distributed Whittier's milk for about a decade and said many of his customers were shocked by the outbreak. Some canceled their service, Gay said, but most seem willing to return to Whittier when the milk is deemed safe.
"They were bumming out, because they love the product," Gay said.