Legionellosis is the name given to all infections caused by the Legionella bacteria. Legionnaires’ disease is the most serious form of infection and initially produces flu like symptoms of fever, chills, chest pain, cough and possibly muscle ache, head ache, loss of appetite, confusion and loss of coordination.

The condition can ultimately develop into acute pneumonia and may also lead to the development of other conditions such as kidney failure and septic shock.

Incubation between exposure and onset of symptoms is between 2 and 10 days (usually 3-6 days). Those patients who do recover following infection may suffer long term and progressive damage to the respiratory system which may lead to a shortened life span.

Treatment is by the administration of antibiotics, with newer drugs offering greater levels of efficacy than those available to the medical services during the original 1976 Philadelphia outbreak.

Pontiac and Lochgoilhead fevers produce similar flu like symptoms of fever and muscle ache but without the progression to pneumonia, and whilst these infections are not as aggressive as Legionnaires’ disease the rate of morbidity across the population is higher.

Patients usually recover without the need for treatment within 2-5 days.