Potential impacts of global warming and climate change on the epidemiology of zoonotic diseases in Canada.

Abstract

Global climate change may add to the risk of infectious diseases faced by Canadians. A warmer climate may permit the northward expansion of certain disease reservoir animal hosts and vectors increasing the risk to Canadians from zoonotic diseases, i.e., diseases that are transmissible between animals and humans. A shorter, less severe winter would prolong the transmission season for many existing Canadian zoonoses, and could allow previously exotic zoonoses that enter Canada to become established. Significant challenges to epidemiological forecasting arise from complex interactions among climatic factors, zoonotic disease agents, other infectious agents, underlying human health and immunity, socio-economic factors, and ecological parameters. Public health officials and health care providers need to be kept informed of the changing nature of zoonotic disease risk in order to be vigilant in the early detection of disease, and to plan to respond to new or increased health risks. Surveillance and public education will also help protect Canadians from any additional zoonotic health risks of climate change. Global warming and climate change Global warming and associated climate change will be important determinants of future Canadian public health. 1 The International Panel on Climate Change (IPCC) accepts projections of a 1.4 to 5.8oC increase in mean global temperature by 2100 as a result of the accumulation of greenhouse gases (carbon dioxide, ozone, methane, nitrous oxide, and water vapour) in the atmosphere. Achievement of Kyoto emissions reduction targets will reduce the rate of warming but will not prevent it. 2 Climate changes in Canada may include increased temperature over most of Canada, especially in winter and at night; reduced soil moisture and summer drought; increased frequency of extreme precipitation events; more severe weather; and an 11 to 77 cm sea-level rise, by 2100. 2 The greatest changes may affect the Arctic. 2,3