BOSTON (AP) – An 87-year-old man has become the third person to die from a deadly bacteria outbreak triggered by consuming tainted milk products from a central Massachusetts dairy, the state health department said Monday.

The latest victim, a resident of Norfolk County, fell ill in November and died Thursday, said Donna Rheaume, spokeswoman for the state department of public health.

The number of people sickened by listeria bacteria also rose to five after health officials linked a 31-year-old Middlesex County woman diagnosed in September with listeriosis to products from the diary.

The infection was detected while the woman was in the hospital to deliver a baby and “both mother and child are doing well,” Rheaume said.

Health officials say the bacteria entered Whittier Farms’ milk supply after it was pasteurized. Two of those victims, a 78-year-old man and a 75-year-old man, died in June and October. Another elderly man and a pregnant woman survived, although the woman miscarried.

The Shrewsbury dairy remains shuttered and its owners are cooperating with officials trying to determine the source of contamination, Rheaume said. The farm delivered milk mostly to homes in the Worcester area.

Managers of the family owned dairy have said in a statement that they were “extremely concerned about the situation and will be working to obtain the results of the investigation.”

“We have taken over a hundred samples, and we should have results from those samples later in the week,” Rheaume said.

Dr. Alfred DeMaria, the state director of communicable disease control, has said initial investigations showed the pasteurization process at the dairy appears to be working properly.

That could mean the listeria bacteria infection may have entered Whittier Farms’ milk supply after it was pasteurized, he said.

The bacteria can cause listeriosis, a rare but potentially fatal disease that can kill babies and people with weakened immune systems and cause miscarriages in pregnant women. Symptoms include fever, headache, stiffness, nausea, abdominal pain and diarrhea.

AP-ES-01-07-08 1815EST