HEALTH authorities are urging people to be alert to the symptoms of Legionnaires’ disease as buildings which were closed as a result of the Covid-19 pandemic begin to reopen.

Legionnaires’ is a type of pneumonia which causes serious illness in people aged over 50, smokers, and those with underlying health conditions.

A milder form of the disease called Pontiac fever causes a flu-like illness. Both diseases are caused by the growth of Legionella bacteria in water systems.

The Health Protection Surveillance Centre (HPSC) is highlighting how many buildings have been closed, or had their use restricted during the Covid-19 pandemic, and says this could increase the risk of Legionella growth in water systems and associated equipment including evaporative air- conditioning systems, water fountains, showers, spa pools, and other equipment if the water systems have not been managed adequately.

Suzanne Cotter, specialist in public health medicine, at the surveillance centre said initial symptoms of the disease may resemble flu.

“The illness is acquired by the inhalation of aerosolised water contaminated with Legionella bacteria,” she said. “The case fatality rate [rate of deaths associated with Legionnaires’ disease] is about 10%.

“The incubation period for Legionnaires’ disease is usually about two to 10 days with symptoms appearing five to six days after infection but may take longer. The illness usually starts with flu-like symptoms including fever, tiredness, headache, and muscle pains.

“This is followed by a dry cough and breathing difficulties that may progress to a severe pneumonia.”

Meanwhile, the surveillance centre has shared guidance from the European Society of Clinical Microbiology and Infectious Diseases for managing Legionella in building water systems during the pandemic and says that before reopening occurs, it is important “all water systems are kept safe for the future health and safety of guests, visitors and staff”.