An elderly patient presented with fever, chest pain and dry cough. Sputum cultured on charcoal yeast medium, the most likely organism is:

Ans. is 'c' i.e., Legionella.Ref: Harrison, 19th/e, p. 1014; Ananthanarayan, 9th/e, p. 401Clinical features of legionella infection (Legionnaire disease) is very similar to other types of pneumonia (lung infection), with symptoms that include - Diarrhea, High grade fever, Cough, Shortness of breath, Muscle aches, Headaches.It's a triad of Pneumonia, diarrhea and encephalitis