Surrey, BC – Health officers are targeting the Guildford Mall cooling towers as the most likely source of an outbreak of Legionnaires’ disease which has landed seven people in hospital.
One source of bacterial contamination which causes pneumonia-like symptoms is the cooling tower at the adjacent Walmart store, authorities confirmed.
Walmart at Guildford is closed today, possibly at the recommendation of the Fraser Health Authority, that the cooling tower be shut down and cleaned.
Dr. Aamir Bharmal, Fraser Health medical officer, told Vancouverite that several cooling towers at Guildford Mall need to be sanitized. But it’s up to the Mall how they do it and they can decide the sections of the mall they need to shut down to carry out the cleaning.
Legionnaires disease was first identified and named in July 1976 when there was an outbreak of pneumonia symptoms among those attending an American Legion’s convention at the Bellevue-Stratford Hotel in Philadelphia. 182 people fell ill and 29 of them died.
It mostly affects people who are immune-compromised, or those with chronic lung disease. The elderly are susceptible.
In 1977 the previously unknown bacteria that caused the illness at the convention was identified and the bacteria responsible was named Legionella pneumophila.
Bharmal said Guildford Mall authorities have been told to clean out the cooling towers. This involves removal of sludge, descaling, and chlorination to kill bacteria that grow in an environment where warm water is present.
Authorities first became aware of the outbreak after extensive follow-up questioning of those cases reported in Surrey. Patients had been asked to list places they had visited and they listed the mall as one of the places where they had been.
That resulted in a sampling of material taken from cooling towers. Bharmal said Walmart has a separate cooling tower but several other towers directly serve the air conditioning systems of the entire mall. However, the mall has not been directed to shut down.
Bharmal said it’s not unusual to find the bacteria growing in cooling towers. The organism can be found in hot tubs and other locations.
After Guildford Mall authorities clean up the towers Fraser Health will retest to make sure public safety is ensured, he said.
“We are not telling people not to go the mall,” he said.
For healthy people Legionella presents very little risk, he said.