Legionnaires’ disease warning: Health chiefs investigating spike of pneumonia-linked bacteria in London
An increase in cases of a serious bacterial infection that can lead to life-threatening pneumonia is being investigated by the UK Health Security Agency (UKHSA).
The agency is examining a cluster of Legionnaires’ disease cases linked to north and south west London.
The illness is caused by Legionella bacteria, which thrive in warm, stagnant water found in places such as shower heads, pipes, water butts, garden hoses and sprinkler systems.
Health officials are reviewing each case reported this year and interviewing patients or their families to retrace their movements in an effort to identify any common link, the UKHSA said.
Around 300 cases of Legionnaires’ disease are reported each year in England and Wales.
The bacteria grow best in temperatures between 20C and 45C and infect people when contaminated droplets of water are inhaled deep into the lungs.
Symptoms typically appear within a few days and include breathlessness, severe chest pain and a high temperature. The infection can cause a severe form of pneumonia.
Most cases occur individually, but outbreaks can happen when a shared water source becomes contaminated.
The illness is caused by Legionella bacteria, which thrive in warm, stagnant water found in places such as shower heads, pipes, water butts, garden hoses and sprinkler systems
The overall risk to the wider public is considered low because the disease rarely spreads from person to person.
Patients are usually treated with antibiotics, which may need to be taken for several weeks.
Those most at risk include smokers, older adults and people with weakened immune systems caused by conditions such as diabetes or cancer.
Dr Janice Lo, consultant in health protection for London at the UKHSA, said: ‘At this stage, a common source has not yet been confirmed, but we are carrying out further investigations with partners which will provide us with more information.
‘Legionella bacteria are widely distributed in the environment and can multiply in large water systems within buildings.
‘It is important that water systems are properly maintained with regular testing and treatment to prevent the bacteria from multiplying and posing a risk to health.’
Investigators are cross-referencing information gathered from patients to identify possible sources of infection.
Managers of cooling towers and large water systems in affected areas have been instructed to treat their systems with high doses of chlorine to eliminate any potential contamination, the UKHSA said.
Early symptoms of Legionnaires’ disease often resemble flu, including muscle aches, tiredness, headaches, dry cough and fever. Anyone experiencing these symptoms is advised to contact NHS 111 or their GP for medical advice.
The disease was first identified in 1976 after several delegates attending a conference in Philadelphia fell ill. Investigators later traced the outbreak to contaminated water droplets circulating through a hotel air-conditioning system.
Although relatively rare, Legionnaires’ disease continues to occur worldwide. The bacteria occur naturally in freshwater but can multiply in poorly maintained water systems.
Experts say unused taps and showers can allow water to sit stagnant, potentially allowing bacteria to grow, which is why some advise running them briefly before use after long periods of inactivity.
While the average fatality rate is around one in ten, it can rise to as high as 30 per cent among people with weakened immune systems.
