This shouldn’t come as much of a surprise. Zika is carried by Aedes aegypti, a mosquito that thrives in warm, tropical climates. For years, epidemiologists have been predicting that tropical diseases, including dengue, malaria, and cholera, will expand their range as the planet heats up.
Warmer temperatures help Zika by increasing the habitat for its mosquito vector, while speeding up the biological processes that help the virus replicate. “With higher temperatures you have more mosquitoes feeding more frequently and having a greater chance of acquiring infection,” Bill Reisen, an entomologist at UC Davis, told the Associated Press. “And then the virus replicates faster because it’s hotter, therefore the mosquitoes can transmit earlier in their life.”
Hotter temperatures also make mosquitoes hungrier, entomologist say, causing them to partake in more blood feasts and upping the odds of their viruses passing to humans.
Some experts urge caution pegging this particular global outbreak to a single weather event or warm year. Others, including University of Washington global health professor Kristie Ebi, are more willing to draw a definitive link. She calls Zika a “temperature driven eruption.”
One way or another, it’s clear that as Aedes aegypti’s habitat expands, the opportunity for Zika to spread will increase in step. All the more reason to start implementing some serious mosquito control measures now.