Vectorborne diseases are diseases that are transmitted from an arthropod (usually a tick or mosquito, etc.) to humans or other animals. Some vectorborne disease agents are maintained primarily through transmission between arthropods and humans (e.g., dengue virus and malaria), while others are maintained between arthropods and animal reservoirs (e.g., Lyme disease and West Nile virus) and humans may become infected incidentally.

Vectorborne Disease and the Environment

Climate is one of many important interacting variables that affect people’s risk for vectorborne diseases in New York City. Warmer winters make it easier for ticks to survive in NYC year-round, while a longer warm season increases the length of time that ticks are active each year. Warming temperatures can lengthen the season in which mosquitoes are out and biting, and accelerate the mosquito life cycle. This can mean more frequent contact between mosquitoes and their hosts, which can facilitate the spread of diseases.

Changing precipitation patterns, with longer periods between rains but heavier rain events, may affect the amount of standing water that mosquitoes have to breed in. Climate change may also alter bird migration patterns or result in changes in deer and small mammal populations that serve as hosts for vectorborne diseases.