A time series analysis of the relationship of ambient temperature and common bacterial enteric infections in two Canadian provinces


The incidence of enteric infections in the Canadian population varies seasonally, and may be expected to be change in response to global climate changes. To better understand any potential impact of warmer temperature on enteric infections in Canada, we investigated the relationship between ambient temperature and weekly reports of confirmed cases of three pathogens in Canada: Salmonella, pathogenic Escherichia coli and Campylobacter, between 1992 and 2000 in two Canadian provinces. We used generalized linear models (GLMs) and generalized additive models (GAMs) to estimate the effect of seasonal adjustments on the estimated models. We found a strong non-linear association between ambient temperature and the occurrence of all three enteric pathogens in Alberta, Canada, and of Campylobacter in Newfoundland-Labrador. Threshold models were used to quantify the relationship of disease and temperature with thresholds chosen from 0 to −10°C depending on the pathogen modeled. For Alberta, the log relative risk of Salmonella weekly case counts increased by 1.2%, Campylobacter weekly case counts increased by 2.2%, and E. coli weekly case counts increased by 6.0% for every degree increase in weekly mean temperature. For Newfoundland-Labrador the log relative risk increased by 4.5% for Campylobacter for every degree increase in weekly mean temperature.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6


  1. Aramini J, McLean M, Wilson J et al (2000) Drinking water quality and health care utilization for gastrointestinal illness in greater Vancouver. Health Canada: Population and Public Health Branch. October

  2. Bentham G, Langford IH (1995) Climate change and the incidence of food poisoning in England and Wales. Int J Biometeorol 39:81–86

    Article  PubMed  CAS  Google Scholar 

  3. Bentham G, Langford IH (2001) Environmental temperatures and the incidence of food poisoning in England and Wales. Int J Biometeorol 45:22–26

    Article  PubMed  CAS  Google Scholar 

  4. Brumback BA, Ryan LM, Schwartz, J, Neas L, Stark P, Burge H (2000) Transitional regression models, with application to environmental time series. J Am Stat Assoc 95:16–27

    Article  Google Scholar 

  5. Canadian Integrated Surveillance Report (2003) Salmonella, Campylobacter, pathogenic E. coli and Shigella, from 1996–1999. Canadian Communicable Disease Report 2951

  6. Canadian Medical Association Journal (2003) Food irradiation: Let’s do it (editorial). Can Med Assoc J 162:5

    Google Scholar 

  7. Dominici F, McDermott A, Zeger SL, Samet JM (2002) On the use of generalized additive models in time-series studies of air pollution and health. Am J Epidemiol 156:193–203

    Article  PubMed  Google Scholar 

  8. D’Souza RM, Becker NG, Hall G, Moodie KBA (2004) Does ambient temperature affect foodborne disease? Epidemiology 15:86–92

    Article  PubMed  Google Scholar 

  9. Environment Canada (2002) “The Climate of Newfoundland.” The Green Lane (Dartmouth, Nova Scotia) http://www.atl.ec.gc.ca/climate/nfld.html)

  10. Hall GV, D’Souza RM, Kirk MD (2002) Foodborne disease in the new millennium: out of the frying pan and into the fire? Med J Aust 177:614–618

    PubMed  Google Scholar 

  11. Hastie TJ, Tibshirani R (1990) Generalized additive models. Chapman and Hall, London

    Google Scholar 

  12. Isaacs S, Leber C, Michel P (1998) The distribution of foodborne disease by risk setting—Ontario. Can Commun Dis Rep 24:61–64

    PubMed  CAS  Google Scholar 

  13. Kovats S, Edwards S, Hajat S, Armstrong BG, Ebi KL, Menne B (2004) The effect of temperature on food poisoning: a time-series analysis of salmonellosis in ten European countries. Epidemiol Infect 132:443–453

    Article  PubMed  CAS  Google Scholar 

  14. Mackey BM, Kerridge AL (1988) The effect of incubation temperature and inoculum size on growth of salmonellae in minced beef. Int J Food Microbiol 6:57–65

    Article  PubMed  CAS  Google Scholar 

  15. Mathsoft (1999) S-PLUS 2000 guide to statistics, vol 1. Data Analysis Products Division, Mathsoft, Seattle, WA

  16. Ramsay TO, Burnett R, Krewski D (2003) Exploring bias in a generalized additive model for spatial air pollution data. Environ Health Perspect 110:1283–1288

    Article  Google Scholar 

  17. Statistics Canada (2002) Population and dwelling counts, for Canada, Provinces and Territories, 2001 and 1996 censuses. Statistical Reference Centre, Ottawa, ON, http://www12.statcan.ca/english/census01/products/standard/popdwell/Table-PR.cfm)

  18. Ulm K, Salanti G (2003) Estimation of the general threshold limit values for dust. Int Arch Occup Environ Health 76:233–240

    PubMed  CAS  Google Scholar 

  19. Woods SN (2004) Stable and efficient multiple smoothing parameter estimation for generalized additive models. J Am Stat Assoc 99:673–686

    Article  Google Scholar 

Download references


We thank Alberta Public Health and Newfoundland and Labrador Centre for Health Information for the use of their notifiable disease data for this study. We also thank the cCASHh study for their support and collaboration and James R. Ferguson, a geographical consultant, for preparing the map for this article.

Author information



Corresponding author

Correspondence to Manon Fleury.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Fleury, M., Charron, D.F., Holt, J.D. et al. A time series analysis of the relationship of ambient temperature and common bacterial enteric infections in two Canadian provinces. Int J Biometeorol 50, 385–391 (2006). https://doi.org/10.1007/s00484-006-0028-9

Download citation


  • Foodborne disease
  • Ambient temperature
  • Time series analysis
  • Climate change
  • Canada