title: Molecular diagnosis of Legionella infections--Clinical utility of front-line screening as part of a pneumonia diagnostic algorithm.
abstract: OBJECTIVE
  Urinary antigen testing for Legionella pneumophila serogroup 1 is the leading rapid diagnostic test for Legionnaires' Disease (LD); however other Legionella species and serogroups can also cause LD. The aim was to determine the utility of front-line L. pneumophila and Legionella species PCR in a severe respiratory infection algorithm.
  
  
  METHODS
  L. pneumophila and Legionella species duplex real-time PCR was carried out on 1944 specimens from hospitalised patients over a 4 year period in Edinburgh, UK.
  
  
  RESULTS
  L. pneumophila was detected by PCR in 49 (2.7%) specimens from 36 patients. During a LD outbreak, combined L. pneumophila respiratory PCR and urinary antigen testing had optimal sensitivity and specificity (92.6% and 98.3% respectively) for the detection of confirmed cases. Legionella species was detected by PCR in 16 (0.9%) specimens from 10 patients. The 5 confirmed and 1 probable cases of Legionella longbeachae LD were both PCR and antibody positive.
  
  
  CONCLUSIONS
  Front-line L. pneumophila and Legionella species PCR is a valuable addition to urinary antigen testing as part of a well-defined algorithm. Cases of LD due to L. longbeachae might be considered laboratory-confirmed when there is a positive Legionella species PCR result and detection of L. longbeachae specific antibody response.
authors.affiliation: Medical Microbiology, Dept Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK. Electronic address: naomi.gadsby@luht.scot.nhs.uk.
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Gadsby
authors.affiliation: Medical Microbiology, Dept Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: Kristjan O
authors.initials: KO
authors.lastname: Helgason
authors.affiliation: Medical Microbiology, Dept Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Dickson
authors.affiliation: Medical Microbiology, Dept Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Mills
authors.affiliation: Scottish Haemophilus, Legionella, Meningococcus and Pneumococcus Reference Laboratory, New Lister Building, Glasgow Royal Infirmary, 10-16 Alexandra Parade, Glasgow, G31 2ER, UK.
authors.forename: Diane S J
authors.initials: DS
authors.lastname: Lindsay
authors.affiliation: Scottish Haemophilus, Legionella, Meningococcus and Pneumococcus Reference Laboratory, New Lister Building, Glasgow Royal Infirmary, 10-16 Alexandra Parade, Glasgow, G31 2ER, UK.
authors.forename: Giles F
authors.initials: GF
authors.lastname: Edwards
authors.affiliation: Medical Microbiology, Dept Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: Mary F
authors.initials: MF
authors.lastname: Hanson
authors.affiliation: Medical Microbiology, Dept Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: Kate E
authors.initials: KE
authors.lastname: Templeton
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D044128:Legionella longbeachae / Q000235:genetics / Q000276:immunology; D016952:Legionella pneumophila / Q000235:genetics / Q000276:immunology; D007876:Legionellosis / Q000175:diagnosis*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D006113:United Kingdom
keywords: Legionella anisa; Legionella hackeliae; Legionella longbeachae; Legionella pneumophila; Legionella species; Legionnaires' Disease; Molecular diagnostics; PCR; Pneumonia