As California warms, cases of dengue fever are expected to grow

Warming temperatures mean potentially more illness

In the new study, researchers at UC Berkeley, UC Santa Barbara, Stanford University, Arizona State University, and from Santa Clara and Los Angeles Counties, modeled the current and future habitat suitability in California for dengue based on predicted warming.

They looked for places with three overlapping qualities: likely presence of host mosquitoes, likely human travel from places where dengue is endemic, and temperatures warm enough for the virus to spread. They confirmed that parts of the Central Valley and Southern California already are well-suited for the virus to circulate locally.

“We found that 18.2 million people currently live in an area where they have those necessary conditions for local dengue transmission,” Couper said. Collectively, that represents 46% of Californians, according to 2020 U.S. census data. That number may increase by more than 4 million in the future.

“And the transmission risk will expand geographically and extend for longer periods seasonally as the climate and land use changes,” MacDonald added.