Bangladesh is battling its worst dengue outbreak on record, with more than 600 people killed and 135,000 cases reported since April, the World Health Organization said Wednesday, as one of its experts blamed the climate crisis and El Nino weather pattern for driving the surge.
The country's health care system is straining under the influx of sick people, and local media have reported hospitals are facing a shortage of beds and staff to care for patients. There were almost 10,000 hospitalizations on August 12 alone, according to WHO.
WHO director-general Tedros Adhanom Ghebreyesus said in a news briefing Wednesday that of the 650 people who have died since the outbreak began in April, 300 were reported in August.
While dengue fever is endemic in Bangladesh, with infections typically peaking during the monsoon season, this year the uptick in cases started much earlier -- toward the end of April.
Tedros said WHO is supporting the Bangladeshi government and authorities "to strengthen surveillance, lab capacity, clinical management, vector control, risk communication and community engagement," during the outbreak.
"We have trained doctors and deployed experts on the ground. We have also provided supplies to test for dengue and support care for patients," he said.
A viral infection, dengue causes flu-like symptoms, including piercing headaches, muscle and joint pains, fever and full body rashes. It is transmitted to humans through the bite of an infected Aedes mosquito and there is no specific treatment for the disease.
Dengue is endemic in more than 100 countries and every year, 100 million to 400 million people become infected, according to WHO.
All 64 districts across Bangladesh have been affected by the outbreak but the capital Dhaka -- home to more than 20 million people -- has been the worst-hit city, according to WHO. Though cases there are starting to stabilize.
"Cases are starting to decline in the capital Dhaka but are increasing in other parts of the country," Tedros said.
Dhaka is one of the most densely populated cities in the world and rapid unplanned urbanization has exacerbated outbreaks.
"There is a water supply problem in Dhaka, so people keep water in buckets and plastic containers in their bathrooms or elsewhere in the home. Mosquitoes can live there all year round," Kabirul Bashar, professor at Jahangirnagar University's Zoology department, wrote in the Lancet journal last month.
"Our waste management system is not well planned. Garbage piles up on the street; you see a lot of little plastic containers with pools of water in them. We also have multi-story buildings with car parks in the basements. People wash their vehicles down there, which is ideal for the mosquitoes."
To cope with the onslaught of infections, Bangladesh has repurposed six Covid-19 hospitals to care for dengue patients and requested help from WHO to help detect and manage cases earlier, WHO said.
Climate crisis spreading and amplifying outbreaks
The record number of dengue cases and deaths in Bangladesh comes as the country has seen an "unusual episodic amount of rainfall, combined with high temperatures and high humidity, which have resulted in an increased mosquito population throughout Bangladesh," WHO said in August.
Those warm, wet conditions make the perfect breeding ground for disease-carrying mosquitoes and as the planet continues to rapidly heat due to the burning of fossil fuels, outbreaks will become more common in new regions of the world.
The global number of dengue cases has already increased eight-fold in the past two decades, according to WHO.
"In 2000, we had about half a million cases and ... in 2022 we recorded over 4.2 million," said Raman Velayudhan, WHO's head of the global program on control of neglected tropical diseases in July.
As the climate crisis worsens, mosquito-borne diseases like dengue, Zika, chikungunya and yellow fever will likely continue to spread and have an ever greater impact on human health.
"We are seeing more and more countries experiencing the heavy burden of these diseases," said Abdi Mahamud, WHO's alert and response director in the health emergencies program.
Mahamud said the climate crisis and this year's El Nino weather pattern -- which brings warmer, wetter weather to parts of the world -- are worsening the problem.
This year, dengue has hit South America severely with Peru grappling with its worst outbreak on record. Cases in Florida prompted authorities to put several counties on alert. In Asia, a spike in cases has hit Sri Lanka, Thailand and Malaysia, among other nations. And countries in sub-Sarahan Africa, like Chad, have also reported outbreaks.
Calling these outbreaks a "canary in the coalmine of the climate crisis," Mahamud said "global solidarity" and support is needed to deal with the worsening epidemic.