People celebrate the arrival of summer every year, but it comes with a downside: an annual population explosion of disease-carrying ticks and mosquitoes. Recent findings from the Centers for Disease Control and Prevention reveal a staggering threefold increase in reported cases of what we broadly term “vector-borne diseases”—or illnesses transmitted to humans by mosquitoes, lice, ticks and the like—between 2004 and 2016 in the United States. Making matters worse, nine new pathogens emerged for the first time in the U.S. during this same period.
What has spurred such a dramatic uptick (no pun intended)? While multiple factors are involved, the influence of climate change cannot be overlooked.
CLIMATE CHANGE AND DISEASE
Since vectors are cold-blooded, changes in temperature alter both the biology and population dynamics of mosquitos and ticks, which in turn impacts their development rates, feeding patterns and reproductive cycles. When temperatures rise, the time between generations of mosquitoes shortens. What’s more, earlier and extended periods of warm weather may prolong the time during which vector populations are able to thrive. (On the flip side, extremely hot temperatures coupled with drier conditions in some areas can have a negative impact on vector populations.)