title: A population-based spatio-temporal analysis of Clostridium difficile infection in Queensland, Australia over a 10-year period.
abstract: OBJECTIVE
  To identify the spatio-temporal patterns and environmental factors associated with Clostridium difficile infection (CDI) in Queensland, Australia.
  
  
  METHODS
  Data from patients tested for CDI were collected from 392 postcodes across Queensland between May 2003 and December 2012. A binomial logistic regression model, with CDI status as the outcome, was built in a Bayesian framework, incorporating fixed effects for sex, age, source of the sample (healthcare facility or community), elevation, rainfall, land surface temperature, seasons of the year, time in months and spatially unstructured random effects at the postcode level.
  
  
  RESULTS
  C. difficile was identified in 13.1% of the samples, the proportion significantly increased over the study period from 5.9% in 2003 to 18.8% in 2012. CDI peaked in summer (14.6%) and was at its lowest in autumn (10.1%). Other factors significantly associated with CDI included female sex (OR: 1.08; 95%CI: 1.01-1.14), community source samples (OR: 1.12; 95%CI: 1.05-1.20), and higher rainfall (OR: 1.09; 95%CI: 1.02-1.17). There was no significant spatial variation in CDI after accounting for the fixed effects in the model.
  
  
  CONCLUSIONS
  There was an increasing annual trend in CDI in Queensland from 2003 to 2012. Peaks of CDI were found in summer (December-February), which is at odds with the current epidemiological pattern described for northern hemisphere countries. Epidemiologically plausible explanations for this disparity require further investigation.
authors.affiliation: School of Population Health, The University of Queensland, Herston, QLD, Australia. Electronic address: l.furuyakanamori@uq.edu.au.
authors.forename: Luis
authors.initials: L
authors.lastname: Furuya-Kanamori
authors.affiliation: Sullivan Nicolaides Pathology, Taringa, QLD, Australia.
authors.forename: Jenny
authors.initials: J
authors.lastname: Robson
authors.affiliation: School of Population Health, The University of Queensland, Herston, QLD, Australia.
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Soares Magalhães
authors.affiliation: School of Population Health, The University of Queensland, Herston, QLD, Australia.
authors.forename: Laith
authors.initials: L
authors.lastname: Yakob
authors.affiliation: School of Population Health, The University of Queensland, Herston, QLD, Australia.
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: McKenzie
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Herston, QLD, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Paterson
authors.affiliation: Microbiology & Immunology, The University of Western Australia and Department of Microbiology PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Riley
authors.affiliation: Research School of Population Health, The Australian National University, Canberra, ACT, Australia.
authors.forename: Archie C A
authors.initials: AC
authors.lastname: Clements
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001499:Bayes Theorem; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile; D003015:Clostridium Infections / Q000453:epidemiology* / Q000209:etiology; D004777:Environment; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011793:Queensland; D011891:Rain; D012621:Seasons; D062211:Spatio-Temporal Analysis; D055815:Young Adult
keywords: Australia; Clostridium difficile; Epidemiology; Infection; Spatio-temporal analysis