Alberta Health Services is investigating an outbreak of legionnaires’ disease in southwest Calgary.
Six people were hospitalized between Nov. 18 and Nov. 23 and are now recovering. The source of the exposure is still unknown, but all of the patients live or work within 16 kilometres of one another.
Investigators are trying to determine what connections — if any — exist between the individuals, who range in age from 51 to 78.
No new cases have been reported since Dec. 1.
“We want to reassure the public that we are following this as we normally would do and are attempting to identify the source of the infection,” Dr. Judy MacDonald, medical officer of health for the Calgary zone, told reporters Friday.
Legionnaire’s disease is a form of pneumonia that is caused by bacteria that flourish in hot water tanks, plumbing and air conditioning systems.
It is contracted by breathing droplets of water contaminated with the bacteria. Most cases can be successfully treated with antibiotics but the disease can be dangerous for people with weakened immune systems.
The bacteria can also be spread through mist in public showers and hot tubs in poorly ventilated areas. Drinking fountains and decorative fountains have also been linked to legionnaires’ disease.
Thirteen people died following an outbreak in Quebec City earlier this year.
The good news, said MacDonald, is that because the bacteria is not transmitted from one person to another, the six Calgary cases do not pose a risk to the public.
There have been 39 confirmed cases of legionnaires’ disease in the city since 2004, including a cluster of nine cases traced back to bacteria at a British Columbia resort.
But investigators are mystified as to why so many people fell ill recently from the pneumonia-like disease, especially in November.