The latest incident in the United States involving bacteria-contaminated milk has claimed the lives of three elderly men and caused at least one pregnant woman to miscarry since last June.
The latest victim, an 87 year old man from Norfolk County, who became ill in November, died last week.
Two other elderly men died earlier of listeriosis, and all three cases of the bacterial disease have been associated with contaminated milk.
Apart from the 3 deaths, there have been other reported cases of people becoming ill after drinking the milk.
The milk produced by a Massachusetts dairy company, Whittier Farms was contaminated with listeria but health officials investigating the outbreak have so far failed to find any fault in the pasteurization process.
The farm in Shrewsbury, is about 35 miles west of Boston and the investigators are now examining the cooling and bottling machinery in their search for the source of the bacteria.
Dr. Alfred DeMaria, state director of communicable disease control says the outbreak is believed to be the third time listeria has ever been linked to pasteurized milk in the United States.
The dairy has suspended all it's operations until the source of the contamination is discovered.
Listeriosis is a rare but potentially fatal disease which can kill babies and people with weakened immune systems; the symptoms include fever, headache, stiffness, nausea, abdominal pain and diarrhea.