title: Native Joint Septic Arthritis: Epidemiology, Clinical Features, and Microbiological Causes in a New Zealand Population.
abstract: OBJECTIVE
  To determine the epidemiology, clinical features, and microbiology of adult native joint septic arthritis in Canterbury, New Zealand, over a 5-year period in individuals with and without an underlying rheumatic disorder.
  
  
  METHODS
  Patients with native joint septic arthritis were identified retrospectively and classified by Newman's criteria. The clinical characteristics were described and comparisons made between those with and without underlying rheumatic disease.
  
  
  RESULTS
  Two hundred forty-eight cases of native joint septic arthritis (mean age 60, range 16-97 yrs) were identified with an overall incidence rate of 12.0/100,000/year (95% CI 10.6-13.6). Yearly incidence increased with age to a maximum of 73.4/100,000 in those > 90 years of age. Septic arthritis was iatrogenic in 16.9% of cases while 27% had an underlying inflammatory arthritis including gout (14.9%), calcium pyrophosphate disease (8.5%), and rheumatoid arthritis (4%). Few patients were taking immunosuppressant therapy, with just 1 taking a biological agent. Staphylococcus aureus was the most commonly identified organism. Those with underlying inflammatory arthritis were significantly older (73.6 yrs vs 55.6 yrs; p < 0.001), more likely to be female (55.2% vs 26.0%; p < 0.001), and to have septic polyarthritis (16.4% vs 4.4%; p = 0.002). The 30-day mortality was 2%, increasing to 6% at 90 days.
  
  
  CONCLUSIONS
  The incidence of septic arthritis in Canterbury, New Zealand, is higher than in previous studies. Crystal arthropathy commonly coexisted with infection although autoimmune arthritis and immunosuppression was less of a factor than anticipated.
authors.affiliation: From the Department of Rheumatology, Immunology and Allergy, the Department of Infectious Diseases, and Decision Support, Christchurch Hospital; the Department of Pathology, and the Department of Medicine, University of Otago; Canterbury Health Laboratories, Christchurch, New Zealand.N. Kennedy, MB ChB, Clinical Immunology/Rheumatology registrar, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital; S.T. Chambers, MB ChB, MD, MSc, FRACP, Professor of Infectious Diseases, Department of Pathology, and Department of Medicine, University of Otago, and Department of Infectious Diseases, Christchurch Hospital; I. Nolan, Medical student, Department of Medicine, University of Otago; K. Gallagher, infectious diseases nurse, Department of Infectious Diseases, Christchurch Hospital; A. Werno, MD, PhD, FRCPA, Medical Director, Microbiology, Canterbury Health Laboratories; M. Browne, Decision Support, Christchurch Hospital; L.K. Stamp, MB ChB, FRACP, PhD, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, and Department of Medicine, University of Otago.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Kennedy
authors.affiliation: From the Department of Rheumatology, Immunology and Allergy, the Department of Infectious Diseases, and Decision Support, Christchurch Hospital; the Department of Pathology, and the Department of Medicine, University of Otago; Canterbury Health Laboratories, Christchurch, New Zealand.N. Kennedy, MB ChB, Clinical Immunology/Rheumatology registrar, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital; S.T. Chambers, MB ChB, MD, MSc, FRACP, Professor of Infectious Diseases, Department of Pathology, and Department of Medicine, University of Otago, and Department of Infectious Diseases, Christchurch Hospital; I. Nolan, Medical student, Department of Medicine, University of Otago; K. Gallagher, infectious diseases nurse, Department of Infectious Diseases, Christchurch Hospital; A. Werno, MD, PhD, FRCPA, Medical Director, Microbiology, Canterbury Health Laboratories; M. Browne, Decision Support, Christchurch Hospital; L.K. Stamp, MB ChB, FRACP, PhD, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, and Department of Medicine, University of Otago.
authors.forename: Steven T
authors.initials: ST
authors.lastname: Chambers
authors.affiliation: From the Department of Rheumatology, Immunology and Allergy, the Department of Infectious Diseases, and Decision Support, Christchurch Hospital; the Department of Pathology, and the Department of Medicine, University of Otago; Canterbury Health Laboratories, Christchurch, New Zealand.N. Kennedy, MB ChB, Clinical Immunology/Rheumatology registrar, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital; S.T. Chambers, MB ChB, MD, MSc, FRACP, Professor of Infectious Diseases, Department of Pathology, and Department of Medicine, University of Otago, and Department of Infectious Diseases, Christchurch Hospital; I. Nolan, Medical student, Department of Medicine, University of Otago; K. Gallagher, infectious diseases nurse, Department of Infectious Diseases, Christchurch Hospital; A. Werno, MD, PhD, FRCPA, Medical Director, Microbiology, Canterbury Health Laboratories; M. Browne, Decision Support, Christchurch Hospital; L.K. Stamp, MB ChB, FRACP, PhD, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, and Department of Medicine, University of Otago.
authors.forename: Imogen
authors.initials: I
authors.lastname: Nolan
authors.affiliation: From the Department of Rheumatology, Immunology and Allergy, the Department of Infectious Diseases, and Decision Support, Christchurch Hospital; the Department of Pathology, and the Department of Medicine, University of Otago; Canterbury Health Laboratories, Christchurch, New Zealand.N. Kennedy, MB ChB, Clinical Immunology/Rheumatology registrar, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital; S.T. Chambers, MB ChB, MD, MSc, FRACP, Professor of Infectious Diseases, Department of Pathology, and Department of Medicine, University of Otago, and Department of Infectious Diseases, Christchurch Hospital; I. Nolan, Medical student, Department of Medicine, University of Otago; K. Gallagher, infectious diseases nurse, Department of Infectious Diseases, Christchurch Hospital; A. Werno, MD, PhD, FRCPA, Medical Director, Microbiology, Canterbury Health Laboratories; M. Browne, Decision Support, Christchurch Hospital; L.K. Stamp, MB ChB, FRACP, PhD, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, and Department of Medicine, University of Otago.
authors.forename: Kate
authors.initials: K
authors.lastname: Gallagher
authors.affiliation: From the Department of Rheumatology, Immunology and Allergy, the Department of Infectious Diseases, and Decision Support, Christchurch Hospital; the Department of Pathology, and the Department of Medicine, University of Otago; Canterbury Health Laboratories, Christchurch, New Zealand.N. Kennedy, MB ChB, Clinical Immunology/Rheumatology registrar, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital; S.T. Chambers, MB ChB, MD, MSc, FRACP, Professor of Infectious Diseases, Department of Pathology, and Department of Medicine, University of Otago, and Department of Infectious Diseases, Christchurch Hospital; I. Nolan, Medical student, Department of Medicine, University of Otago; K. Gallagher, infectious diseases nurse, Department of Infectious Diseases, Christchurch Hospital; A. Werno, MD, PhD, FRCPA, Medical Director, Microbiology, Canterbury Health Laboratories; M. Browne, Decision Support, Christchurch Hospital; L.K. Stamp, MB ChB, FRACP, PhD, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, and Department of Medicine, University of Otago.
authors.forename: Anja
authors.initials: A
authors.lastname: Werno
authors.affiliation: From the Department of Rheumatology, Immunology and Allergy, the Department of Infectious Diseases, and Decision Support, Christchurch Hospital; the Department of Pathology, and the Department of Medicine, University of Otago; Canterbury Health Laboratories, Christchurch, New Zealand.N. Kennedy, MB ChB, Clinical Immunology/Rheumatology registrar, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital; S.T. Chambers, MB ChB, MD, MSc, FRACP, Professor of Infectious Diseases, Department of Pathology, and Department of Medicine, University of Otago, and Department of Infectious Diseases, Christchurch Hospital; I. Nolan, Medical student, Department of Medicine, University of Otago; K. Gallagher, infectious diseases nurse, Department of Infectious Diseases, Christchurch Hospital; A. Werno, MD, PhD, FRCPA, Medical Director, Microbiology, Canterbury Health Laboratories; M. Browne, Decision Support, Christchurch Hospital; L.K. Stamp, MB ChB, FRACP, PhD, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, and Department of Medicine, University of Otago.
authors.forename: Melanie
authors.initials: M
authors.lastname: Browne
authors.affiliation: From the Department of Rheumatology, Immunology and Allergy, the Department of Infectious Diseases, and Decision Support, Christchurch Hospital; the Department of Pathology, and the Department of Medicine, University of Otago; Canterbury Health Laboratories, Christchurch, New Zealand.N. Kennedy, MB ChB, Clinical Immunology/Rheumatology registrar, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital; S.T. Chambers, MB ChB, MD, MSc, FRACP, Professor of Infectious Diseases, Department of Pathology, and Department of Medicine, University of Otago, and Department of Infectious Diseases, Christchurch Hospital; I. Nolan, Medical student, Department of Medicine, University of Otago; K. Gallagher, infectious diseases nurse, Department of Infectious Diseases, Christchurch Hospital; A. Werno, MD, PhD, FRCPA, Medical Director, Microbiology, Canterbury Health Laboratories; M. Browne, Decision Support, Christchurch Hospital; L.K. Stamp, MB ChB, FRACP, PhD, Department of Rheumatology, Immunology and Allergy, Christchurch Hospital, and Department of Medicine, University of Otago. Lisa.Stamp@cdhb.health.nz.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Stamp
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001170:Arthritis, Infectious / Q000188:drug therapy* / Q000453:epidemiology* / Q000382:microbiology; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D010147:Pain Measurement; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D015996:Survival Rate; D013582:Synovial Fluid / Q000382:microbiology; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents
keywords: CRYSTAL ARTHROPATHY; EPIDEMIOLOGY; NATIVE JOINT; NEW ZEALAND; SEPTIC ARTHRITIS