Four infected with Legionella

Hamilton public health is investigating whether four cases of legionellosis in the city’s east end came from a common source.

The cases were reported to public health over the past several weeks. The first person became sick on Aug. 11 and reported it Aug. 23. The three other cases have been reported since Sept. 22.

“Legionella is a seasonal thing so we do expect more cases at this time of the year. And, in fact, the number of cases is not large at all,” Dr. Chris Mackie, an associate medical officer of health, said Friday.

But public health is trying to trace whether the disease came from the same source in the east end, he said, noting that one of the cases was contracted while the patient was travelling outside of the country.

The elderly, people with lung conditions or immune disorders and smokers are more susceptible, Mackie said.

Legionnaires’ disease is a severe form of pneumonia caused by the Legionella pneumophila bacterium, commonly found in large cooling systems. The bacteria live in water or wet soil and must be inhaled or aspirated to cause an infection.

The city has looked into about the half a dozen cooling towers in the area and did not find concerns, Mackie said.

A medical advisory was issued to Hamilton physicians, infection control officers, labs, intensive care units and other health care professionals to flag Legionellosis as a potential diagnosis for pneumonia cases.