title: The efficacy of filters used in respiratory function apparatus.
abstract: The ability of two low resistance barrier filters (Collins DC-1 and Pall Pf 305) to remove bacteria from expired air was assessed. A specially designed coupling device was used to hold each filter or a disposable plain cardboard mouthpiece a fixed distance (4.5 cm) from a blood agar plate. Volunteers performed maximal forced vital capacity manoeuvres through the assembled apparatus and bacteria impinged on to the agar plate were enumerated. Both filters allowed the transmission of approximately one-third of expired colony forming units. The efficacy of these filters for reducing the likelihood of cross-infection during spirometry is not supported by this study.
authors.affiliation: Bristol Public Health Laboratory, Bristol Royal Infirmary, UK.
authors.forename: J P
authors.initials: JP
authors.lastname: Leeming
authors.forename: D M
authors.initials: DM
authors.lastname: Pryce-Roberts
authors.forename: A H
authors.initials: AH
authors.lastname: Kendrick
authors.forename: E C
authors.initials: EC
authors.lastname: Smith
mesh_terms: D000391:Air Microbiology; D001419:Bacteria / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D015169:Colony Count, Microbial; D003428:Cross Infection / Q000382:microbiology / Q000517:prevention & control; D003470:Culture Media; D003550:Cystic Fibrosis / Q000382:microbiology*; D004866:Equipment Contamination / Q000517:prevention & control; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D012129:Respiratory Function Tests / Q000295:instrumentation*
chemical_list: D003470:Culture Media