India is experiencing an overwhelming increase in dengue cases. The cause is climate change. Aliya Bashir reports
Dengue fever is rife in India. In 2022, 230 000 infections and 303 deaths were attributed to the disease—although this is likely to be an underestimate as the majority of cases are mild, asymptomatic, or misdiagnosed. Antibodies against dengue virus have been found in around 50% of the Indian population.1
The Indian Council of Medical Research (ICMR) says that all states and union territories report cases, with rural areas accounting for 41-45% of the national total in 2021.
“There are no existing treatments for uncomplicated dengue fever to prevent progression to severe disease and other complications, and doctors are only managing the symptoms,” says Kavita Singh, director for South Asia at the Drugs for Neglected Diseases Initiative (DNDi), although a vaccine is available.
Transmitted to humans by infected female Aedes aegypti mosquitoes, dengue control focuses on managing mosquito populations—making the disease one of the most prominent examples of how climate change translates into mortality.
“The frequency of outbreaks is ever increasing,” says Himmat Singh, a scientist at the National Institute of Malaria Research in New Delhi. “Mosquitoes are evolving as humans have pushed them to adapt. Climate change is adding to the health crisis in India.”
There are four known serotypes of dengue virus—DENV-1, 2, 3, and 4—with co-circulation of all four becoming a common feature in most tropical countries in recent years.
Most people who are infected with dengue virus for …