How climate change made 2024 the deadliest year of dengue

Neelika Malavige knows first hand the toll that dengue can take. As a junior doctor in Sri Lanka who worked in a paediatric unit, she has witnessed three children dying from dengue during her time as an intern house officer. These deaths motivated her to learn more about the immunological response to the vectorborne disease.

In Sri Lanka, every patient with dengue who presents with symptoms is monitored carefully. Severe dengue can lead to serious complications: plasma leakage, fluid accumulation, respiratory distress, severe bleeding, and organ impairment.

The four dengue virus serotypes have all been circulating in Sri Lanka for more than 30 years. Since 2019, Sri Lanka’s zero dengue death policy has been a large part of the health ministry’s national dengue action plan. Keeping your surroundings clean, spraying insecticide, and eliminating mosquito breeding sites are common practices for dengue control around the world. Sri Lanka is also focusing on early detection of complications, to reduce the number of deaths caused by the severe form of the disease.

“We’ve intensified epidemiological surveillance to detect and notify dengue cases in real time,” says Malavige, now an an immunologist and professor at the University of Sri Jayewardenepura in Sri Lanka. “We’re focusing on preventing severe cases and ensuring that we have a more coordinated public health response to the disease,” she says.

There have been record numbers of cases of the disease this year, with the global incidence surpassing 2023, which was itself a record breaking year.1 The disease is endemic in many low and middle income countries, but 2024 has seen many cases in many higher income countries. More than 12 million …