Global Warming Driving Expanded Dengue Outbreaks - 4.6 Million Cases/Year Attributable To Higher Temperatures

Global cases of flu-like dengue fever reached a historic high last year, with over 14.6 million cases and more than 12,000 related deaths reported to the World Health Organization. Global warming is driving up those infection numbers in a big way, a new study suggests. Transmitted by the Aedes aegypti mosquito, the dengue virus is common across tropical and subtropical regions in Asia and the Americas. Nearly one-fifth of cases in recent decades can be directly attributed to rising temperatures, researchers at Stanford, Harvard and Arizona State universities and the National Bureau of Economic Research found.

Analyzing local dengue caseloads and climate data within 21 countries where the virus is endemic, the scientists found that rising temperatures were responsible for an average of 18 percent of reported cases between 1990 and 2014. That’s about 260,000 infections caused by climate change each year, based on reported caseloads. “This is not just hypothetical future change, but a large amount of human suffering that has already happened because of warming-driven dengue transmission,” said Erin Mordecai, a Stanford infectious disease ecologist and senior author on the study.

Reported cases likely represent just a fraction of the total dengue burden, Mordecai noted. Accounting for underreporting, global warming may have caused as many as 4.6 million infections each year across the study area, the authors wrote.

Their research answers questions about climate change that have long troubled infectious disease experts, said Heidi Brown, an epidemiologist studying mosquito-borne diseases at the University of Arizona. Brown was not involved in the study. In laboratory experiments, warming up to a certain point, around 29 degrees Celsius (84 degrees Fahrenheit), is known to accelerate the reproduction and development of both Aedes aegypti mosquitoes and the virus they carry, Brown said.

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https://insideclimatenews.org/news/12092025/global-warming-dengue-fever-outbreaks/