The mosquito-borne disease has been on the uptick in France for several months amid warmer temperatures. 

The timing isn’t great—it’s a big summer for the country as it’s hosting the Olympics starting late July, which promises to bring in millions of visitors in addition to the usual tourist crowd.

So, France has put its “dengue detectives” to task. They’ll track down disease hotspots, seek out mosquito eggs, and help curb the spread of the virus in French cities. 

“It’s true the Olympic Games are a critical moment,” Cécile Somarriba, director of health monitoring and safety at the Greater Paris Regional Health Agency (ARS), told The Telegraph. “We are prioritizing our surveillance in places that will host large gatherings. This is where risk of transmission is highest.”

The ARS launched a campaign to watch mosquito numbers in Paris and surrounding suburbs by deploying 526 nesting traps that will be sent for analysis every month.  

The so-called detectives are cracking down on the Aedes albopictus, also known as the Asian tiger mosquito, which thrives in the conditions that cities like Paris offer in summertime—a mix of hot and wet weather, with lots of people coming and going. 

With the Paris Olympics around the corner and expected to welcome over 15 million visitors, authorities are tightening controls in “fan zones” where visitors from around the world might gather, like airports. 

Dengue symptoms include high fever, headaches and nausea. Severe infections can result in deaths, although they are rare if detected early. 

The high alert surrounding dengue cases comes just months after France faced a massive bedbug infestation across Paris’s public transport networks. At the time, the country was gearing up to host the Rugby World Cup, adding pressure on the French transport authority to do away with the pests swiftly. 

Last year, data analytics firm Airfinity warned of a 50-fold jump in locally transmitted dengue cases across France by 2030, thanks to global warming. 

The threat of vector-borne diseases like dengue has climbed in the last few months, hitting an all-time high at the end of April.

Earlier this year, French health officials warned about the risk of imported dengue cases, as the number of cases in the Americas had swelled. 

While it’s hard to weed out the virus altogether, given the massive inflow of visitors, there are ways to control the spread. 

To monitor the situation, health authorities have set up a website and are calling hotels, schools, and other locations to report and detect possible outbreaks early. At some Olympics venues, they are setting up traps that exude human-like odors designed to lure mosquitos.

Parisians are also encouraged not to let stagnant water collect in their gardens so mosquitoes don’t breed.