Published Date: 2012-08-05 04:10:22
Subject: PRO/EDR> Legionellosis - Canada: (Quebec) fatal, cooling tower susp.
Archive Number: 20120805.1228680
LEGIONELLOSIS - CANADA: (QUEBEC) FATAL, COOLING TOWER SUSPECTED
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Fri 3 Aug 2012
Source: 570news.com [edited]
An elderly person has died from Legionnaires' disease during a Quebec City outbreak that has caused 14 other cases.
Authorities suspect the cause might be the air-conditioning system in a large public building -- although they haven't identified the building yet. The regional public-health authority has sent a notice to the owners of all large buildings within a 1.5km area to clean their cooling towers. It believes the bacteria that causes Legionnaires' [disease] developed in the stagnant water in one of those towers connected to the air-conditioning system.
Legionnaires' disease is contracted by breathing in small droplets of water contaminated with the _Legionella_ bacteria. The symptoms are similar to those of flu, including coughs, fever and chills. The disease is not contagious and cannot be transmitted from one person to another. It presents little or no risk to most people, although elderly people are more vulnerable. Radio-Canada reports that the victim [who died was] an 88-year-old woman.
ProMED-mail from HealthMap alerts
[For a discussion of Legionnaires' disease, see ProMED-mail post Legionellosis - UK (02): (Scotland) 20120605.1156972.
Genotyping of patient and environmental isolates has become a helpful tool to establish transmission pathways. The predominance of one genotype of _Legionella_ isolated from patient specimens would suggest transmission from a common source. Because _Legionella_ may be found in environmental samples without linkage to any cases of legionellosis, the actual causative infectious reservoir can be confirmed by matching the genotype of clinical and environmental isolates (see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC86783/ and http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2730281/).
However, clinical isolates are often not available because the diagnosis of Legionnaires' disease is commonly made on the basis of serology or the _Legionella_ urinary antigen test, and not by culture of patient specimens.
A map of the affected area can be accessed at http://healthmap.org/r/2Z0O. Mod.ML]