The symptoms are similar to those of flu, i.e. high temperature, fever and chills, cough, muscle pains and headache. In a severe case, there may also be pneumonia, and occasionally diarrhoea, as well as signs of mental confusion. Legionnaires’ disease is not known to spread from person to person.
In most cases, symptoms develop in 2 to 10 days following exposure to the legionella bacteria. As mentioned, common symptoms include headache, muscle pain and fever. For some people, that is as far as the disease will go. Others, however, will experience a dangerous escalation of symptoms beginning 2 or 3 days after the original onset. Those new, more severe symptoms may include:
- Cough (often with mucus and sometimes blood).
- Respiratory distress in the form of shortness of breath or wheezing.
- An escalating fever perhaps reaching as high as 104F (40C), sometimes higher.
- A heavy sensation in the chest or chest pain.
- Diarrhoea, nausea and/or vomiting.
- Confusion, loss of mental sharpness.
- Infections in other parts of the body besides the lungs.
A less severe form of Legionnaires’ Disease commonly known as “Pontiac Fever” will typically produce similar symptoms but not to any extreme degree. For instance, there is no coughing up blood and no lung infection. Pontiac Fever typically resolves in 2 to 5 days.
When should you see a doctor?
If you are exhibiting any of the above symptoms or have any reason to suspect exposure to legionella bacteria, you should see your doctor immediately for a legionella test. Early detection is critical if you are to avoid it developing into a serious respiratory condition. Keep in mind too that the risk of exposure is more acute for older individuals and smokers.