The pneumonic form – “legionnaire’s disease” – has an incubation period of two to 10 days, but periods of up to 16 days have been reported in some recent outbreaks. Initial symptoms are fever, loss of appetite, headache, malaise, and lethargy. Some patients also report muscle pain, diarrhea, and confusion. In addition, mild cough is observed in the initial days and up to 50% of patients may have phlegm. In 33% of these patients, these can be expectorant with blood.
