Vector-borne pathogens spend part of their life cycle in cold-blooded arthropods that are subject to many environmental factors. Changes in weather and climate that can affect transmission of vector-borne diseases include temperature, rainfall, wind, and sea level rise.

Rodent-borne pathogens can be affected indirectly by ecological determinants of food sources affecting rodent population size.

Examples of Temperature Effects on Selected Vector-Borne Pathogens

Vector

Survival can decrease or increase depending on the species.

Some vectors have higher survival at higher latitudes and altitude with higher temperatures.

Changes in the susceptibility of vectors to some pathogens (e.g., higher temperatures reduce the size of some vectors but reduce the activity of others).

Changes in the rate of vector population growth.

Changes in feeding rate and host contact (which may alter the survival rate).

Changes in the seasonality of populations.

Pathogen

Decreased extrinsic incubation period of pathogen in vector at higher temperatures.

Changes in the transmission season.

Changes in distribution.

Decreased viral replication.

Examples of Effects of Changes in Precipitation on Selected Vector-Borne Pathogens

Vector

Increased rain may increase larval habitat and vector population size by creating a new habitat.