The Rise of Non-native Vectors and Reservoirs of Human Diseases

Abstract

Globalisation has led to unprecedented changes in the distribution and incidence of human diseases. Pathogens, animal vectors, and reservoir species have been unintentionally displaced across natural geographic boundaries, resulting in serious human suffering and enormous economic costs. Non-native diseases can also threaten ecosystems and put ecosystem services and human well-being at risk. Introduced species and environmental interactions have caused manifold new risks and challenges for public health. Mosquitoes and ticks are the most important non-native vectors of human diseases, although many different species can serve as non-native reservoir hosts. In addition to imports as contaminants with cargo, the pet trade is an important pathway of introduction for non-native vectors and reservoirs. Evidence suggests that global environmental change will further facilitate emerging outbreaks of non-native human diseases, some of which may be re-emerging old foes. The complex interrelationships between native and non-native hosts, vectors, and pathogens entail inherent uncertainties and make predictions about future outbreaks very challenging. Natural ecosystems provide a regulating service for human well-being, and the loss of biodiversity therefore represents a serious threat to human health. The linkages between humans, animals, and environmental health are becoming more apparent and call for collaborative efforts (‘One Health’) towards a more responsible ecosystem stewardship.