Event Update: According to a media report, ▲one new case of Legionnaires' disease has been reported in Calgary this year, but so far, the source of the cluster that broke out months ago in the city's southwest remains unknown.
Public health officials are continuing to investigate the cluster, which sent eight people to hospital in November and December, said Alberta Health Services spokeswoman Shannon Evans.
"The cluster still includes the eight cases that were identified as of end of December. One additional case reported in 2013 is being investigated, on the belief that it may have an epidemiological link to the cluster," she said. "But, again, no sources identified or confirmed, no change in investigation status."
Alberta Health Services (AHS) reports that it is investigating a community outbreak of Legionellosis (legionnaires’ disease) in the Calgary Zone. There have been eight confirmed cases to date. The investigation is focused on identifying potential community sources of exposure to Legionella bacteria, however, public health officials remain puzzled over the source of the potentially deadly infection.
Reported between Nov. 27 and Dec. 14, 2012, all eight cases have experienced serious respiratory illness (pneumonia) requiring admission to hospital. Health officials are still investigating whether the most recent case involves the same type of Legionella bacteria as the others.
Because Legionella bacteria are not transmitted person-to-person, the cases do not present a risk to the general public.
"Although the risk of contracting legionnaires’ disease is generally considered to be very low, this recent cluster of illness is unusual, particularly at this time of year,” says Dr. Judy MacDonald, Medical Officer of Health – Calgary Zone. “By swiftly establishing a multidisciplinary investigation team, we have infectious diseases, public health, infection prevention and control, and microbiology experts collaborating to ensure all avenues of inquiry are covered.”
Humans can develop Legionellosis (legionnaires’ disease) when water containing high concentrations of Legionella bacteria becomes aerosolized, such as through showers, fountains, humidifiers or other processes that create a mist of water which can then be inhaled. See Hazards tab for more information.
The AHS investigation will include review of potential aerosolized water sources. Additionally, AHS has advised Calgary-area community and specialist physicians of the illness cluster, requesting that legionnaires’ disease be considered when assessing cases of severe unexplained respiratory illness or pneumonia, which may be accompanied by symptoms of headache, malaise, rapidly rising fever, chills, abdominal pain, and diarrhea.
The public can be assured that AHS is responding to this cluster of illness, and will provide further investigation updates as new information becomes available.