Testing for Legionella many months later?

I am the patient/nurse who had Legionnaires’ disease and was waiting for results from a hot tub and shower. I had a positive urine antigen. The hot tub was culture positive but the showerhead was culture negative. We are still waiting to see if the culture yields L. pneumophila type 1. The person who stayed after me had Pontiac Fever according to the epidemiologist.

Question: If he had symptoms several weeks ago, are there any laboratory tests that may confirm this diagnosis? The epidemiologist thought it was too late to test him. 


The antibody serology (blood test) can remain positive for 3 – 6 months (or longer in some cases) after the infection.