Two people have died after contracting Legionnaire’s disease, a different but severe form of pneumonia that can be fatal if left untreated, at a New Jersey hospital, state health officials confirmed.

Overall, six patients - three men and three women - at Saint Peter’s University had been diagnosed with the disease.

Old Bridge resident Eugene Dutton, 58, died on Sept. 12, a day after testing positive. The second death occurred Monday, two days after the patient tested positive. His identity has not been made public citing confidentiality guidelines. There were 26 patients who could have been exposed to the bacteria, but only six contracted the disease.

Legionnaire’s disease affects mostly people who have weakened immune systems, are over the age of 50, are smokers or already have lung problems. Symptoms include high fever, chills and cough. Legionnaires' disease can be successfully treated with antibiotics, and most people recover from the illness. Annually, the disease affects between 8,000 and 18,000 people.

One usually contracts the disease by inhaling a bacterium most often found in sources of standing water, such as air conditioning ducts, storage tanks and rivers.

According to John D’Anna, the hospital’s chief medical officer, tests run on the hospital’s water system, after the first diagnosis, showed the presence of Legionella bacteria, which cause the disease. The bacteria were found in both hot- and cold-water samples. The hospital’s officials will continue to chlorinate the water in order to get rid of the bacteria. Also patients are provided bottled water until a confirmation about the water quality will be given.

Legionnaire’s disease was named and identified in 1976 after a group of American Legion members who were sickened by bacteria in the air conditioning at a Philadelphia hotel where they were attending a convention.