Future challenges for parasitology: vector control and one health in the Americas.

"One Health" is a term that encapsulates and underscores the inherent interrelatedness of the health of people, animals, and the environment. Vector-borne infections are central in one health. Many arthropod vectors readily feed on humans and other animals, serving as an ideal conduit to move pathogens between a wide spectrum of potential hosts. As ecological niches flux, opportunities arise for vectors to interact with novel species, allowing infectious agents to broaden both geographic and host ranges. Habitat change has been linked to the emergence of novel human and veterinary disease agents, and can dramatically facilitate expansion opportunities by allowing existing vector populations to flourish and by supporting the establishment of new pathogen maintenance systems. At the same time, control efforts can be hindered by the development of parasiticide and pesticide resistance, foiling efforts to meet these challenges. Using examples drawn from representative diseases important in one health in the Americas, including rickettsial infections, Lyme borreliosis, Chagas disease, and West Nile virus, this paper reviews key aspects of vector-borne disease maintenance cycles that present challenges for one health in the Americas, including emergence of vector-borne disease agents, the impact of habitat change on vector-borne disease transmission, and the complexities faced in developing effective control programs. Novel strategies will be required to effectively combat these infections in the future if we are to succeed in the goal of fostering an environment which supports healthy animals and healthy people.