Raman Velayudhan, who leads the World Health Organization’s program for the control of neglected tropical diseases, said about half the world’s population is now at risk for dengue, as a rapidly changing climate yields warmer and wetter weather that provides ideal breeding conditions for mosquitoes and risks exacerbating the situation.
“Dengue is a problem linked mostly with climate change, and we need to find ways to mitigate its impacts on every country level,” Velayudhan said during a webinar last week, adding that more outbreaks are expected in Bangladesh and other parts of Asia following the monsoon season.
Cases reported to the WHO hit an all-time high in 2019, at 5.2 million in 129 countries, “and we expect 2023 also to be a bad year as indications are,” Velayudhan said.
The U.N. health agency warned in January that dengue’s rapid spread represented a pandemic-level threat.
Globally, rates of dengue have continued to rise. In March, the WHO declared dengue a “major public health problem” for the Americas region, and Peru extended a health emergency this summer after experiencing the largest dengue outbreak in the country’s history.
At its worst, dengue can cause high fevers, serious organ failure and death. There are four strains of the virus, and a second infection with a different variation than the first increases the risk of severe dengue.
In Bangladesh, as of Saturday morning, nearly 2,500 patients suffering from high fever, joint pain and vomiting had been admitted to hospitals across the country over the previous 24 hours, according to its Directorate General of Health Services.
The Health Ministry has required major public hospitals to add hundreds of beds for dengue patients, and the government has launched awareness campaigns to encourage the use of mosquito nets, reduce water accumulation near homes and public venues, and kill mosquito larvae following rainfall.
Still, researchers have warned that the peak of the dengue outbreak in Bangladesh is yet to come.
Aedes mosquitoes, the species that transmits dengue and zika, two of the most serious mosquito-borne viruses, start a breeding burst during the wet season, which is followed by a dry period, when they migrate to urban areas in search of water. The monsoon season in Bangladesh usually lasts from June to October.
Mushtaq Hossain, a senior adviser to Bangladesh’s Institute of Epidemiology, Disease Control and Research, said the government was far from ready for a prolonged dengue crisis.
In an opinion piece for the independent Bangladesh Pratidin newspaper, he warned that the number of dengue patients could continue to increase until as late as November after the monsoon season.
The virus, he added, was also likely to pose a risk to the country “throughout the year.”
“We are not adequately prepared to deal with dengue,” he said.