Nearly a fifth of the existing dengue cases globally are attributed to climate change. By 2050, rising temperatures could be responsible for a 60 per cent increase in dengue cases if emissions continue at the current pace.
In India, the number has increased from 2,33,251 with 303 deaths in 2022 to 2,89,235 cases in 2023 with deaths increasing to 485, according to government data
Nearly a fifth of the existing dengue cases globally are attributed to climate change. By 2050, rising temperatures could be responsible for a 60 per cent increase in dengue cases if emissions continue at the current pace.
Research presented by the American Society of Tropical Medicine and Hygiene recently quantified the role of climate change in the increasing cases of dengue finding that there is significant correlation between the two.
The number of dengue cases worldwide is increasing every year, setting new records each year. Data from the World Health Organization show that more than 12mn cases and 6,991 deaths have been recorded globally till August this year, doubling from last year, which itself was a record. Before that, over the past decade, around 2–3mn dengue cases were reported yearly at most.
In India, the number has increased from 2,33,251 with 303 deaths in 2022 to 2,89,235 cases in 2023 with deaths increasing to 485, according to government data. The geography of the infection has also expanded over the years. The disease spread from only eight states and Union Territories (UT) in 2001 to every state and UT in 2022.
The researchers analysed data on dengue across 21 countries in Asia and the Americas over an average of 11 years.
It was found that the mosquitoes that carry dengue — called Aedes aegypti — transmit the virus most efficiently when temperatures are between 68 and 82 degrees Fahrenheit ie., 20 and 27.8 degrees Celsius. Even if global greenhouse gas emissions are reduced significantly, most of the countries would still see rising number of dengue incidences that are climate-induced, the research found.
“We should be expecting these sorts of large epidemics in the future,” said Mallory Harris, a co-author of the research and a postdoctoral associate in the University of Maryland’s biology department. “The risks of this are going to increase regardless, so we need to be thinking about mitigation,” Harris added.
Experts have been warning about the impact of climate change in the surge of dengue for quite some time. The data on increasing cases makes it evident that not enough is being done. It is about time that governments increased surveillance, mosquito control programmes and community awareness campaigns to mitigate the disease.