Climatic factors influence the growth and survival of pathogens, as well as transmission pathways (1). Higher ambient temperatures increase replication cycles of food-borne pathogens, and prolonged seasons may augment the opportunity for food handling mistakes - in 32% of investigated food-borne outbreaks in Europe “temperature misuse” is considered a contributing factor (2).
Campylobacter is the most commonly reported gastrointestinal bacterial disease, and is caused by the thermophilic Campylobacter spp bacteria. In 2007, the European Union incidence was 45.2 cases per 100 000 population (200 507 confirmed cases) and broiler meat as well as fresh poultry meat were the biggest identified sources of infections3. Colonisation of broiler-chicken flocks with campylobacter increases rapidly with raising temperatures. The risk of campylobacteriosis is positively associated with mean weekly temperatures, although the strength of association is not consistent in all studies (4, 5, 6).
The second largest number of human food-borne diseases is caused by the Salmonella spp bacteria. In 2007, the European Union incidence was 31.1 cases per 100 000 population (151 995 confirmed cases) with eggs being the biggest contributors to these outbreaks followed by fresh poultry and pig meat (3). Higher ambient temperatures have been associated with 5-10% higher salmonellosis notifications for each degree increase in weekly temperature, for ambient temperatures above 5oC 8 9. Roughly one-third of the transmission of salmonellosis (population attributable fraction) in England and Wales, Poland, the Netherlands, the Czech republic, Switzerland and Spain can be attributed to temperature influences.
Temperature has the most noticeable effect on salmonellosis and food poisoning notifications 1 week before disease onset, indicating inappropriate food handling and storage at the time of consumption. Indeed, an analysis of food-borne illnesses from England and Wales showed that the impact of the temperature of the current and preceding week has decreased over the past decades, indicating that the potential risk from elevated temperatures related to climate change can be counteracted through concerted public-health action. Thus, regardless of climatic factors, health-behaviour interventions and food-safety regulations should be able to attenuate possible negative consequences on public health. Indeed, bacterial enteric infections have recently started to decrease throughout Europe, in part due to control measures.
Source: Semenza JC, Menne B. Climate Change and Infectious Diseases in Europe. Lancet ID. 2009;9:365-75.
- Food and Agriculture Organization of the United Nations (FAO); Climate Change: Implications for Food Safety (2008).Rome: Food and Agriculture Organization of the United Nations, 2008. (accessed April 15, 2009) http://www.fao.org/docrep/010/i0195e/i0195e00.htm.
- Tirado C, Schmidt K. WHO surveillance programme for control of foodborne infections and intoxications: preliminary results and trends across greater Europe. J Infect. 2001;43(1):80-4.
- European Food Safety Authority. The Community Summary Report on Trends and Sources of Zoonoses and Zoonotic Agents in the European Union in 2007. The EFSA Journal 2009, 223:1-215.
- Kovats RS, Edwards SJ, Charron D, Cowden J, D'Souza RM, Ebi KL, Gauci C, Gerner-Smidt P, Hajat S, Hales S, Hernandez Pezzi G, Kriz B, Kutsar K, McKeown P, Mellou K, Menne B, O'Brien S, van Pelt W, Schmid H. Climate variability and campylobacter infection: an international study. Int J Biometeorol. 2005;49(4):207-14. Epub 2004 Nov 23.
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- Bi P, Cameron AS, Zhang Y, Parton KA. Weather and notified Campylobacter infections in temperate and sub-tropical regions of Australia: an ecological study. J Infect. 2008;57(4):317-23.
- D'Souza RM, Becker NG, Hall G, Moodie KB. Does ambient temperature affect foodborne disease? Epidemiology. 2004;15(1):86-92.
- Kovats RS, Edwards SJ, Hajat S, Armstrong BG, Ebi KL, Menne B. The effect of temperature on food poisoning: a time-series analysis of salmonellosis in ten European countries. Epidemiol Infect. 2004;132(3):443-53.
- Lake IR, Gillespie IA, Bentham G, et al. A revolutionary of the impact of temperature and climate change on foodborne illness. Epidemiol Infect 2004; 132:443-53