every time As the Olympics approach, it seems a different disease has taken its toll on the event. At Rio 2016 it was Zika. At the postponed Tokyo Games it was Covid. And at the Tokyo Olympics it was Covid. 2024 Paris Olympics Which season will be best this summer? Take your pick. Officials are working to contain dengue and measles, which are on the rise in France and many other countries.
During this summer’s Olympics and Paralympics, millions of people from all over the world will converge on the host city: French authorities are preparing to welcome more than 15 million visitors to the country. Even for a capital used to mass tourism – around 40 million people visit Paris each year – this is a huge influx of people. Some will bring infectious diseases with them. Others, who do not have sufficient immunity, risk contracting something during their stay. Dengue and measles are already a problem in Paris, so officials are planning how to limit the possibility of the Games becoming a superspreader event.
“With dengue, it’s very difficult to limit the risk of an epidemic,” says Anna-Bella Failloux, a medical entomologist at the Pasteur Institute in Paris. The virus is transmitted from person to person by mosquitoes, with the invasive tiger mosquito the main culprit in France, aedes albopictus aedes albopictusThis insect becomes a bigger problem when the weather gets warmer, and Europe’s hot summers are creating the conditions for this species to thrive. “The eggs are very resistant, and the mosquito’s metabolism speeds up with the heat. The insect becomes an adult sooner, and, therefore, it bites sooner too.”
Tiger mosquitoes are not new to France: they arrived in the south only in 2004, and have been in Paris since 2015. Originally from Asia, they lay eggs in pockets of stagnant water, which can hatch several weeks later, even after the water has evaporated. This explains how the insect spread across Europe, arriving first in Genoa, Italy, then in France.
Dengue, however, is a recent problem. With the virus raging in tropical parts of the world – with nearly 10 million cases reported worldwide this year, with South America and South-East Asia badly affected – France has seen a rise in cases. Between January 1 and April 30, 2024, health officials recorded 2,166 casesAn average of only 128 cases were reported daily during the same period over the past five years. Most of this year’s cases were imported from the French overseas departments of Guadeloupe, Martinique and French Guiana, where epidemics are ongoing, but the European Centre for Disease Control and Prevention has recorded a few cases of infection inside Europe this year, including in France.
This suggests that the event may have been attended by people from all over the world, while cases are rising rapidly worldwide. If this leads to a rise in the number of imported cases in Paris, the abundance of tiger mosquitoes is likely to spread the virus domestically.
For most people, the infection is a Asymptomatic or have mild symptoms, such as feverBut the disease becomes more severe in some people, and it can be fatal. There is no specific treatment for the virus, and few Europeans already have any immunity. Vaccines have only become available in the last few years, and are only available in a few high-infection countries.
