title: Three, if by air.
authors.forename: Kent A
authors.initials: KA
authors.lastname: Sepkowitz
authors.forename: Barry M
authors.initials: BM
authors.lastname: Farr
mesh_terms: D000391:Air Microbiology; D001228:Aspergillosis / Q000517:prevention & control / Q000635:transmission*; D003428:Cross Infection / Q000382:microbiology / Q000635:transmission*; D006801:Humans; D017053:Infection Control; D014376:Tuberculosis / Q000517:prevention & control / Q000635:transmission*; D014481:United States