title: Legionnaires' disease caused by Legionella longbeachae: Clinical features and outcomes of 107 cases from an endemic area.
abstract: Legionella longbeachae is a predominant cause of Legionnaires' disease in some parts of the world, particularly in Australasia. Clinical reports of L. longbeachae infection are limited to case reports or small case series, and culture-confirmed cases.
  
  
  
  We reviewed the clinical characteristics and outcomes of L. longbeachae pneumonia in a large case series from Christchurch, New Zealand during a 4-year period when both PCR and cultures were used as routine diagnostic tools for Legionnaires' disease. Cases of Legionella pneumophila pneumonia were reviewed for comparison.
  
  
  
  A total of 107 cases of L. longbeachae infection were identified by PCR and/or culture. The median age was 65 years (range 25-90 years), 63% were male, and most became unwell during spring or summer. Presenting clinical features were similar to those reported for community-acquired pneumonia, with headache, myalgia and diarrhoea being common. Elevated C-reactive protein, hyponatraemia and abnormal liver function tests were also common. History of productive cough, involvement of both lungs, and high bacterial load were independently associated with culture of Legionella from lower respiratory samples. One quarter required intensive care unit admission, and 5% died. Among patients given antimicrobial therapy before admission, those given agents without anti-Legionella activity were more likely to be admitted to the intensive care unit. Limited comparisons were made with the 19 L. pneumophila cases over the same time period.
  
  
  
  Characteristics of L. longbeachae pneumonia are broadly similar to those reported for community-acquired pneumonia from a variety of other populations, except for the spring/summer seasonality.
authors.affiliation: Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Heather L
authors.initials: HL
authors.lastname: Isenman
authors.affiliation: Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand.|Department of Pathology, University of Otago, Christchurch, New Zealand.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Chambers
authors.affiliation: Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Alan D
authors.initials: AD
authors.lastname: Pithie
authors.affiliation: Department of Radiology, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Sharyn L S
authors.initials: SL
authors.lastname: MacDonald
authors.affiliation: Department of Radiology, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Justin M
authors.initials: JM
authors.lastname: Hegarty
authors.affiliation: Department of Radiology, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Joanna L
authors.initials: JL
authors.lastname: Fenwick
authors.affiliation: Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Maze
authors.affiliation: Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Sarah C L
authors.initials: SC
authors.lastname: Metcalf
authors.affiliation: Department of Pathology, University of Otago, Christchurch, New Zealand. david.murdoch@otago.ac.nz.|Microbiology Unit, Canterbury Health Laboratories, Christchurch, New Zealand. david.murdoch@otago.ac.nz.
authors.forename: David R
authors.initials: DR
authors.lastname: Murdoch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044362:Australasia; D005260:Female; D006801:Humans; D044128:Legionella longbeachae; D016952:Legionella pneumophila; D007877:Legionnaires' Disease / Q000175:diagnosis* / Q000382:microbiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D016896:Treatment Outcome; D055815:Young Adult
keywords: Legionella longbeachae; Legionnaires' disease; clinical features; pneumonia; polymerase chain reaction