title: Climate variability, weather and enteric disease incidence in New Zealand: time series analysis.
abstract: BACKGROUND
  Evaluating the influence of climate variability on enteric disease incidence may improve our ability to predict how climate change may affect these diseases.
  
  
  OBJECTIVE
  To examine the associations between regional climate variability and enteric disease incidence in New Zealand.
  
  
  METHODS
  Associations between monthly climate and enteric diseases (campylobacteriosis, salmonellosis, cryptosporidiosis, giardiasis) were investigated using Seasonal Auto Regressive Integrated Moving Average (SARIMA) models.
  
  
  RESULTS
  No climatic factors were significantly associated with campylobacteriosis and giardiasis, with similar predictive power for univariate and multivariate models. Cryptosporidiosis was positively associated with average temperature of the previous month (β =  0.130, SE =  0.060, p <0.01) and inversely related to the Southern Oscillation Index (SOI) two months previously (β =  -0.008, SE =  0.004, p <0.05). By contrast, salmonellosis was positively associated with temperature (β  = 0.110, SE = 0.020, p<0.001) of the current month and SOI of the current (β  = 0.005, SE = 0.002, p<0.050) and previous month (β  = 0.005, SE = 0.002, p<0.05). Forecasting accuracy of the multivariate models for cryptosporidiosis and salmonellosis were significantly higher.
  
  
  CONCLUSIONS
  Although spatial heterogeneity in the observed patterns could not be assessed, these results suggest that temporally lagged relationships between climate variables and national communicable disease incidence data can contribute to disease prediction models and early warning systems.
authors.affiliation: Department of Public Health, University of Otago, Wellington, New Zealand.
authors.forename: Aparna
authors.initials: A
authors.lastname: Lal
authors.affiliation: Dean's Department, University of Otago, Wellington, New Zealand.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Molecular Epidemiology and Public Health laboratory, Hopkirk Research Institute, Massey University, Palmerston North, New Zealand.
authors.forename: Nigel
authors.initials: N
authors.lastname: French
authors.affiliation: Department of Public Health, University of Otago, Wellington, New Zealand.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Baker
authors.affiliation: Department of Public Health, University of Otago, Wellington, New Zealand.
authors.forename: Simon
authors.initials: S
authors.lastname: Hales
mesh_terms: D057231:Climate Change; D003141:Communicable Diseases / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D015233:Models, Statistical; D009520:New Zealand / Q000453:epidemiology; D011891:Rain; D012621:Seasons; D013696:Temperature; D013997:Time Factors; D014887:Weather