Montreal public health investigating 3 cases of Legionnaires' Disease

Montreal public health officials are investigating three cases of legionellosis, known as Legionnaires' Disease, including one death.

The Montreal Regional Public Health Department said Wednesday the three cases were reported in the Anjou and Mercier West areas between July 29 and Aug. 8. One of the three people, a man, died from complications of the disease.

The three cases took place in an area east of Highway 25, south of Highway 40 west of George V Avenue and north of the St. Lawrence River. An investigation is underway to determine if all three cases were exposed to the same source. Public health said that the investigation specifically targets the cooling towers with perimeter water.

"Right now, we're trying to find out if these cases are linked," said Jean-Nicholas Aubé, spokesperson for CIUSSS du Centre-Sud-de-l'Île-de-Montréal.

SYMPTOMS 

The cases are not cause for alarm among the general population, Aubé said. Nevertheless, public health is encouraging Montrealers to remain vigilant for symptoms similar to pneumonia or even COVID-19, including:

• high fever
• chills
• cough
• fatigue
• muscle aches
• loss of appetite

Symptoms may appear two to 10 days after exposure to the bacteria. As with COVID-19, call 811 or seek medical attention at the onset of these symptoms.

Aubé said that while transmission of the disease is rare, it's not unheard of in Montreal, with cases reported to public health every year.

Last year, there were 52 reports of Legionnaire's disease. This year, as of today, there have been 27 reports.

SOURCES

Legionella bacteria, which causes the disease, can be found in the environment, mainly in fresh water, but sometimes in significant quantities in artificial water sources like water cooling towers or water heaters.

The disease cannot be transmitted by drinking contaminated water, Aubé specified. Rather, it's transmitted through inhaling contaminated water droplets in the air.

The primary sources of infection are:

• Drinking water systems (especially hot water): water heaters, shower heads or faucet aerators
• Water cooling towers
• Spas, hot tubs, whirlpools or Jacuzzis
• Home humidifiers
• Respiratory treatment devices (e.g. CPAP)

WHO'S AT RISK 

Public health officials said the chances of contracting the disease are very low, even in vulnerable people. It is not transmitted from person to person and does not usually affect healthy people.

"The disease rarely, and I mean rarely, affects people that are in good shape," said Aubé.

There is a greater risk for people:

• Over the age of 50
• Who smoke
• Who drink a lot of alcohol
• With a chronic disease
• Who are immunocompromised
• Who have had recent surgery

The fatality rate of Legionnaires' Disease is about 10 to 15 per cent but varies with age, health status, severity of illness, and the time to start antibiotic treatment, officials said.