Why dengue in Europe could spell disaster for the rest of the world

Increased investment into previously neglected diseases could see poorer countries left behind.

In the early morning of the last day of August, Parisians experienced for the first time a practice normally confined to tropical regions — authorities fumigating the city against the tiger mosquito. The event was a tangible confirmation of what public health stats already showed: Dengue, the deadly mosquito-borne disease, had well and truly arrived in Europe. 

In 2022, Europe saw more cases of locally acquired dengue than in the whole of the previous decade. The rise marks both a public health threat and a corresponding market opportunity for dengue vaccines and treatments; news that should spur the pharma industry to boost investment into the neglected disease. 

On the face of it, this shift would appear to benefit not only countries like France but also nations like Bangladesh and the Philippines that have long battled dengue.

But that assumption could be fatally flawed, experts told POLITICO. 

People working in the field say the rise of dengue in the West could, in fact, make it harder to get lifesaving drugs to those who need them most, because pharma companies develop tools that are less effective in countries where the dengue burden is the highest or because wealthy nations end up hoarding these medicines and vaccines. 

“It might look like a good thing — and it is a good thing — that we’re getting more products developed, but does it then create a two-tier system where high-income populations get access to it and then we still have the access gap for low- and middle- income countries?” asked Lindsay Keir, director of the science and policy advisory team at think tank Policy Cures Research.

Killer invading mosquitoes

Climate change and migration mean the mosquitoes that transmit dengue, as well as other diseases such as chikungunya and Zika, are setting up shop in Europe. The most recent annual data from the European Centre for Disease Prevention and Control shows that, in 2022, Europe saw 71 cases of locally acquired dengue: 65 in France and six in Spain.

While dengue usually results in mild or no symptoms, it can also lead to high fever, severe headache and vomiting. Severe dengue can cause bleeding from the gums, abdominal pain and, in some cases, death.

So far, the mosquito has mostly been confined to Southern Europe but it’s a worry across the Continent. In Belgium, the national public health research institute Sciensano has even launched an app where members of the public can submit photos of any Asian tiger mosquitos they spot.