title: Spatial and temporal patterns of locally-acquired dengue transmission in northern Queensland, Australia, 1993-2012.
abstract: BACKGROUND
  Dengue has been a major public health concern in Australia since it re-emerged in Queensland in 1992-1993. We explored spatio-temporal characteristics of locally-acquired dengue cases in northern tropical Queensland, Australia during the period 1993-2012.
  
  
  METHODS
  Locally-acquired notified cases of dengue were collected for northern tropical Queensland from 1993 to 2012. Descriptive spatial and temporal analyses were conducted using geographic information system tools and geostatistical techniques.
  
  
  RESULTS
  2,398 locally-acquired dengue cases were recorded in northern tropical Queensland during the study period. The areas affected by the dengue cases exhibited spatial and temporal variation over the study period. Notified cases of dengue occurred more frequently in autumn. Mapping of dengue by statistical local areas (census units) reveals the presence of substantial spatio-temporal variation over time and place. Statistically significant differences in dengue incidence rates among males and females (with more cases in females) (χ(2) = 15.17, d.f.  = 1, p<0.01). Differences were observed among age groups, but these were not statistically significant. There was a significant positive spatial autocorrelation of dengue incidence for the four sub-periods, with the Moran's I statistic ranging from 0.011 to 0.463 (p<0.01). Semi-variogram analysis and smoothed maps created from interpolation techniques indicate that the pattern of spatial autocorrelation was not homogeneous across the northern Queensland.
  
  
  CONCLUSIONS
  Tropical areas are potential high-risk areas for mosquito-borne diseases such as dengue. This study demonstrated that the locally-acquired dengue cases have exhibited a spatial and temporal variation over the past twenty years in northern tropical Queensland, Australia. Therefore, this study provides an impetus for further investigation of clusters and risk factors in these high-risk areas.
authors.affiliation: School of Public Health and Social Work & Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove campus, Brisbane, Queensland, Australia.
authors.forename: Suchithra
authors.initials: S
authors.lastname: Naish
authors.affiliation: Environmental Futures Centre, Australian Rivers Institute, Griffith School of Environment Griffith University, Brisbane, Queensland, Australia.
authors.forename: Pat
authors.initials: P
authors.lastname: Dale
authors.affiliation: Australian Biosecurity CRC and Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia.
authors.forename: John S
authors.initials: JS
authors.lastname: Mackenzie
authors.affiliation: School of Medicine and Dentistry, James Cook University, Cairns, Queensland, Australia.
authors.forename: John
authors.initials: J
authors.lastname: McBride
authors.affiliation: Mathematical Sciences, Queensland University of Technology, Gardens Point campus, Brisbane, Queensland, Australia.
authors.forename: Kerrie
authors.initials: K
authors.lastname: Mengersen
authors.affiliation: School of Public Health and Social Work & Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove campus, Brisbane, Queensland, Australia.
authors.forename: Shilu
authors.initials: S
authors.lastname: Tong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000453:epidemiology* / Q000635:transmission*; D005260:Female; D005843:Geography; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011793:Queensland / Q000453:epidemiology; D012621:Seasons; D062206:Spatial Analysis; D013223:Statistics as Topic; D013997:Time Factors; D055815:Young Adult