Why you should care
Hundreds have died of dengue this year, and scientists predict it’s only going to get worse.
Authorities in Brazil have reported an explosion in the number of cases of dengue fever as increasingly extreme weather patterns fuel the spread of the potentially lethal mosquito-borne disease.
In recent years, Brazil has suffered a string of outbreaks of mosquito-borne diseases, including yellow fever in the São Paulo region last year as well as the Zika virus, which spread rapidly through the northeast in 2015.
Some scientists have argued that the current outbreak of dengue, which triggers severe flu-like symptoms, can be attributed to the spread of Zika, which they say left Brazilians more susceptible to the tropical illness. No matter the reason, the numbers are startling:
In the first six months of 2019, Latin America’s largest nation recorded almost 1.2 million dengue cases — a jump of almost 600 percent from the same period last year.
The number of deaths rose 220 percent to 388. The development is likely to exacerbate concerns about the public health impact of global warming at a time when many world leaders, including Brazil’s president, Jair Bolsonaro, are showing little appetite to protect the environment.
The surge is particularly concerning for scientists given it has extended into the winter season, when the disease should decline.
“This year is very different because we have had dengue fever circulating for much longer — and the cause of this is global warming,” says Ester Sabino, a professor at the Institute of Tropical Medicine at the University of São Paulo. “We have had more days with high temperatures, so mosquitoes continue to multiply.”
Officials at the Brazilian Ministry of Health and other experts have also pointed to increasingly extreme weather patterns, including soaring temperatures and high volumes of rain, as well as the emergence of a new strain of dengue from the Caribbean.
Average temperatures in Brazil are expected to increase by as much as 6 degrees Celsius by the end of the century, according to the Brazilian Panel on Climate Change.
Dengue fever predominantly affects poorer Brazilians. In the absence of running water, many residents of the country’s favelas use open water tanks to collect rainfall — a setup that invariably attracts mosquitoes.
Sabino says the risk of such diseases spreading worldwide will become more acute in the coming years as temperatures rise.
“With global warming, Europe, for example, will also be exposed to these mosquitoes and, consequently, diseases such as dengue. We [already] have cases of the chikungunya virus in Spain,” she says.
Bolsonaro is an outspoken skeptic of the global climate crisis. At one point he said he would pull his nation out of the Paris climate accord.
At the recent G-20 summit in Osaka, Japan, Bolsonaro decried global concerns about climate change, telling German Chancellor Angela Merkel that Brazil had become the target of “environmental psychosis.”
The spread of mosquito-borne diseases in South America, meanwhile, has been aided by the collapse of the Venezuelan health care system. Between 2016 and 2017 alone, the number of malaria cases in the nation jumped 70 percent.
In February a report published in The Lancet medical journal warned of an epidemic of malaria and dengue fever as a result of the continuing crisis in Venezuela.
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