Climatic change and emerging arthropod-borne diseases: challenges for global human and animal health

Walter J. Tabachnick

Florida Medical Entomology Laboratory, University of Florida, USA

Vector-borne pathogens cause enormous suffering to humans and animals. Malaria causes millions of deaths annually. There are many other insect-borne pathogens that also cause significant morbidity and mortality. Many are expanding into their range into new areas. Dengue, West Nile and chikungunya have recently caused substantial human epidemics. Arthropod-borne animal diseases such as bluetongue, Rift Valley fever, and African horse sickness pose substantial threats to livestock economies around the world. Climate change can impact the vector-borne disease epidemiology. Changes in climate will influence arthropod vectors, their life cycles and life histories, resulting in changes in both vector and pathogen distribution and changes in the ability of arthropods to transmit pathogens. Climate can affect the way pathogens interact with both the arthropod vector and the human or animal host. Predicting and mitigating the effects of climate change on the complex arthropod–pathogen–host epidemiological cycle requires understanding of a variety of complex mechanisms from the molecular to the population level. Although there has been substantial progress on many fronts, the challenges to effectively understand and mitigate the impact of potential changes in climate on vector-borne pathogens are formidable and at an early stage of development. The challenges will be explored using several arthropod-borne pathogen systems as an illustration, and potential avenues to meet the challenges will be presented.