Everyone is potentially at risk from Legionella bacteria and of developing Legionellosis. Legionellosis is the collective term for illnesses caused by the Legionella bacteria. Legionnaires’ disease is the most serious disease caused by exposure to Legionella bacteria and results in the lungs becoming infected by the bacteria. Other conditions caused by the bacteria include Pontiac Fever and Lochgoilhead Fever.
Whilst everyone is at risk from Legionella, certain things make it more likely that you will experience a more severe form of the infection. The National Health Service (NHS) advise that these factors include:
- being 50 years of age or over – 235 (83%) of the 284 confirmed cases in 2013 involved people over 50 years of age
- smoking, or having smoked heavily in the past (a recent study has shown that smoking cannabis may also increase your risk)
- drinking alcohol heavily
- about three-quarters have an underlying medical condition, such as diabetes, kidney disease, or a pre-existing lung condition
- having a weakened immune system – for example, people with HIV and AIDS or cancer
Babies and children can also be at higher risk from Legionella as they have immune systems that are still developing.
The initial symptoms of Legionnaires’ Disease are very similar to many other diseases. They are also often mistaken for flu. These symptoms can include:
- mild headaches
- muscle pain
- high temperature (fever), usually 38C (100.4F) or above
- changes to your mental state, such as confusion
As the disease develops the bacteria can begin to infect your lungs. At this stage you may also experience the symptoms of pneumonia. These symptoms can include:
- a persistent cough – which is usually dry at first, but as the infection develops you may start coughing up phlegm or, rarely, blood
- shortness of breath
- chest pains
Unsurprisingly, the NHS advise that you see your GP as soon as possible if you develop the symptoms above. Additionally they advise that you seek urgent medical attention if you have more severe symptoms, such as chest pain and breathing difficulties.
Legionnaires’ disease is a notifiable disease in the UK. This means that if a doctor diagnoses the condition, they must tell the local authority under The Health Protection (Notification) Regulations 2010. The authority will try to identify the source of the outbreak and put in place any necessary precautionary measures.