title: How many Legionnaires.
mesh_terms: D000368:Aged; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007877:Legionnaires' Disease / Q000382:microbiology*; D008168:Lung / Q000382:microbiology; D012703:Serotyping / Q000379:methods; D013194:Staining and Labeling / Q000379:methods