Legionnaires’ disease is pneumonia.

My aunt and grandma went on a cruise to Greece. They both returned sick and still suffer from shortness of breath, fatigue, and muscle weakness, including pulmonary edema. Their MD says there is nothing wrong and they have a mental problem causing these symptoms. I wonder if they could have Legionnaires’ disease. What are your suggestions? 

It is unclear if Legionnaires’ disease is the cause of their symptoms. I suggest that your relatives consult an infectious disease specialist. A chest x-ray taken at the time of their illness may be especially useful. Both a blood test for Legionella antibodies (serology) and possibly a urine antigen for Legionella may be useful diagnostic aids.

Your relatives may also notify their local health dept or the health dept where the cruise ship is located. Many outbreaks of Legionnaire’ disease have been linked to cruise ships.