Dengue will ‘take off’ in southern Europe, US and Africa this decade, says WHO scientist

Dengue fever will become a major threat in the southern United States, southern Europe and new parts of Africa this decade, WHO’s chief scientist said, as temperatures rise Hot weather creates the conditions necessary for the spread of mosquitoes carrying the infection.

The disease has long been a scourge across much of Asia and Latin America, causing around 20,000 deaths each year. Disease rates have already increased eightfold globally since 2000, largely driven by climate change as well as increased human movement and urbanization.

Many cases go unrecorded, but in 2022, 4.2 million cases have been reported worldwide and public health officials have warned that near-record levels of transmission are expected this year. Bangladesh is currently experiencing the worst outbreak on record, with more than 1,000 deaths.

“We need to talk about dengue much more proactively,” Jeremy Farrar, an infectious disease specialist who joined the World Health Organization in May this year, told Reuters.

“We really need to prepare countries for how they will deal with the additional pressure that will arise…in the future in many, many large cities.”

Farrar spent 18 years working in Vietnam on tropical diseases, including dengue. He went on to lead global health charity Wellcome Trust and advise the UK government on its response to Covid-19 before joining the WHO in May this year.

Farrar said the infection is likely to “take off” and become endemic in parts of the United States, Europe and Africa – all areas where there has already been limited local transmission – as global warming makes new areas hospitable for the mosquitoes that spread it. . This will put acute pressure on hospital systems in many countries, he warned.

“Clinical care is very intensive and requires a high ratio of nurses to patients,” he said. “I really worry when this becomes a major problem in sub-Saharan Africa.”

Most people with dengue do not have any symptoms, meaning case rates would be much higher than reported figures. Those who do so may experience fever, muscle spasms, and joint pain so severe that it is called “fracture fever.” In severe cases – less than 1% – it can be fatal.

There is no specific treatment for dengue fever, although there is a vaccine. Earlier this week, WHO recommended Takeda Pharmaceuticals’ Qdenga vaccine for children aged 6 to 16 in areas where infection is a significant public health problem.

Qdenga is also approved by the European regulator, but Takeda withdrew its application in the United States earlier this year, citing data collection issues. Takeda said he was still in talks with the U.S. Food and Drug Administration about the vaccine.

Preparing new parts of the world to deal with dengue means ensuring that all public health funds are spent in the right areas, Farrar said, including on how best to control the mosquito.

Dengue is spread by infected Aedes aegypti mosquitoes, which behave differently from malaria-carrying mosquitoes. For example, they bite people internally and bite all day rather than all night. They also breed in very shallow water.

Farrar said proper prevention would include triage plans for hospitals as well as scientific innovation as well as other key factors, such as urban planning, to avoid areas of standing water near or in homes .

“We need to combine different sectors that are not used to working together,” he said.