Health authorities have warned of the growing incidence of Legionnaires’ disease in Ireland with a record level of the potentially fatal infection notified last year.
New figures show that the number of cases of Legionnaires’ disease more than doubled in 2017 to 25, resulting in four deaths.
In 2016, there were 10 cases, with one associated death.
The HSE’s Health Protection Surveillance Unit said last year’s figures were above historical rates and represented the highest level since figures were recorded in 2000.
The annual trend over the last six years indicates that the number of case notifications of Legionnaires’ disease has been increasing over time,” said a HSE spokeswoman.
The incidence of the disease is now 5.3 cases per million population but 13.8 per million among those aged over 50 years.
The disease is caused by legionella, a common bacterium found in many water-related sources where temperatures are between 20C and 45C such as hot and cold water pipes, air conditioning systems, condensers, humidifiers, taps, showerheads, fountains, jacuzzis, spas ,and sprinkler systems.
The infection is spread through the air from the water source with people becoming ill after they inhale mist or steam containing tiny droplets of water which have been contaminated with legionella.
The disease can affect all age groups but is most common among those aged over 50 years.
Smokers, heavy drinkers, and those with chronic illnesses whose immune systems are weakened are considered at greater risk.
The illness, which usually starts between two and ten days after infection, has flu-like symptoms including fever, tiredness, headache and muscle pains.
These symptoms can be followed by a dry cough and breathing difficulties that can progress to severe pneumonia.
It is estimated that Legionnaires’ disease is fatal in 10-15% of cases.
The majority of cases recorded in Ireland last year related to older males with two-thirds of cases involving people living in the greater Dublin region.
The HSE said 11 patients are believed to have contracted the infection while abroad from visits to countries including Spain, Turkey, the UK, and the United Arab Emirates.
The HSE has provided hotels, leisure centres, nursing homes, and other similar facilities with checklists on how to reduce the threat from Legionnaire’s disease with the warning that an outbreak on their premises could have significant legal consequences.
The disease acquired its name following an outbreak of pneumonia among delegates attending an American Legion convention in Philadelphia in 1976 in which 29 out of 182 cases died.