Keeping average global warming below 1.5°C could prevent millions of new cases of dengue fever within the disease’s current geographic range, and arrest its spread to new areas, reports a research team from the United Kingdom and Brazil.
Faster action on climate “could halt the spread of dengue fever in the Western Hemisphere and avoid more than three million new cases a year in Latin America and the Caribbean by the end of the century,” InsideClimate News reports. “The tropical disease, painful but not usually fatal, afflicts hundreds of millions of people around the world.” And with no vaccine available to treat dengue, “controlling its spread by reining in global warming would be a significant health benefit.”
The study, published in May in the Proceedings of the National Academy of Sciences, “is part of an urgent effort by scientists around the world to collect evidence on the difference between 2.0° of warming and 1.5° under the auspices of the Intergovernmental Panel on Climate Change (IPCC), which is due to report on the latest science this fall,” InsideClimate notes.
The study compared dengue infection patterns at 1.5° and 2.0°C against a business-as-usual scenario of 3.7°C, and found a clear connection between rising temperatures and the spread of the disease. At 3.7°, researchers forecast 12.1 million more cases per year in Latin America and the Caribbean. But that toll falls to 9.3 million cases at 2.0°, or 8.8 million at 1.5°.
“In Brazil alone, global warming of no more than 1.5°C might prevent 1.4 million dengue cases a year,” ICN notes.
While southern Mexico, the Caribbean, Ecuador, Colombia, Venezuela, and the coastal regions of Brazil would see the greatest impacts, 3.7°C average global warming could also make dengue more common in regions that have seen few cases in the past. People in those areas would be particularly vulnerable, ICN adds, since they lack any immunity to dengue and local public health systems are “woefully unprepared for dealing with major dengue epidemics.”