Climate Change and Public Health: Emerging Infectious Diseases

Climate restricts the range of infectious diseases, whereas weather affects the timing and intensity of outbreaks. Climate change scenarios project a change in the distribution of infectious diseases with warming and changes in outbreaks associated with weather extremes, such as flooding and droughts. The hypothesis of this article is that the ranges of several key diseases or their vectors are already changing in altitude due to warming, along with shifts in plant communities and the retreat of alpine glaciers. In addition, more intense and costly weather events create conditions conducive to outbreaks of infectious diseases, as heavy rains leave insect breeding sites, drive rodents from burrows, and contaminate clean water systems. Conversely, drought can spread fungal spores and spark fires (and associated respiratory disease). In addition, sequences of extremes can destabilize predator/prey interactions, leading to population explosions of opportunistic, disease-carrying organisms. Advances in climate forecasting and health early warning systems may prove helpful in catalyzing timely, environmentally friendly public health interventions. If climate change continues to be associated with more frequent and volatile and severe weather events, we have begun to see the profound consequences that climate change can have for public health and the international economy.