The legionella bacterium - the cause of deadly legionnaires’ disease - could be mutating, threatening the lives of thousands.
Experts attending the Combatting Legionella conference in Manchester next week (30-31 March) say the bacterium has been seen surviving well beyond safety temperature guidelines, and in chemicals designed to kill it.
And compounding the risk in Britain is the “shoddy” and even fabricated monitoring of water systems in care homes, hotels, schools and other establishments.
Simon French of Water Hygiene Training, EplusGlobal and Legionella consultant to the HVCA Education/Service and Facilities Group said: “Legionnaires’ disease is far more common than we think. Around 9,000 people are estimated to contract it annually in the UK. Around 12 per cent of these die, but the figure is likely to be much higher - up to 50 per cent - in the old and infirm.
“Everyone associates Legionnaires’ disease with cooling towers, but it has also been discovered in car washes, windscreen water, dental chairs and even compost heaps.
“But by far the greatest risk lies within the humble hot and cold water systems that deliver the disease through taps and shower heads. Legionella bacteria thrive in temperatures between 20-45 deg C, and if water is allowed to sit at these temperatures the bacteria can multiply.”
However, new evidence indicates that some strains of legionella have been able to survive in temperatures of up to 61 deg C; they are normally killed at temperatures from 50 deg C. They have also been found in biocides, which are designed to kill them.
Until recently, babies had never been affected - but two years ago, 11 infants in a neonatal unit in Cyprus contracted Legionnaires’ disease, and four died.
David Harper, an industry consultant and expert witness in criminal and coroners’ courts, contracted Legionnaires’ disease and died three times in intensive care. He also found legionella in an outbreak at Stafford District General Hospital in which 28 people died, tracing it to a contaminated cooling tower linked to the AC unit.
He said: “I am lucky to be here, so it troubles me that tougher economic times could be leading to shortcuts. Several risks exist here, not least shutting water heating systems down or lowering temperatures to save electricity, thus plunging water into the 20-45 deg C breeding zone.
“I have personally seen people fabricating entries in log books. These logs are designed to identify the dangers in ‘breeding zones’ in internal pipework, so any form of tampering is irresponsible.”
Louise Webster, of Black Box Intelligence, which produces monitoring systems, said: “In an era of reduced staff and budgets, and higher workloads, there is more room for human error. Even if monthly checks are meticulous, who knows what’s happening day in, day out, as temperatures fluctuate in any system?”
HVCA vice-president and chair of the Association’s Service and Facilities Group Sue Sharp said: “Building owners/users and their facilities managers must be aware of the increasing dangers posed by the disease, and must ensure that adequate steps are taken to control the circumstances in which the legionella bacterium is likely to thrive.”