A third man has died after consuming products from a central Massachusetts dairy that were tainted with deadly bacteria, the state health department revealed Monday.

The victim, an 87-year-old man identified only as being from Norfolk County, fell ill in November and was pronounced dead last Thursday, according to Donna Rheaume, representative for the state Department of Public Health.

The incident comes after health officials issued a warning in late December encouraging consumers to toss any Whittier milk products.

The number of people who fell ill by listeria bacteria after consuming products from the diary rose to five after health officials linked a 31-year-old woman’s listeriosis, diagnosed in September to the same products. The woman was diagnosed with the disease while being in the hospital to deliver her baby. According to Rheaume, both mother and baby are in good health.

Health officials reported that the bacteria entered Whittier Farms’ milk supply after it was pasteurized. A 78-year-old man and a 75-year-old man who died in June and October number among the victims of listeria bacteria.

Meanwhile the Shrewsbury diary remains closed 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.

“The investigation is ongoing,” Rheaume said several times.

Symptoms of listeriosis include fever, headache, stiffness, nausea, abdominal pain and diarrhea and can lead to the death of babies and people with weakened immune systems.