The Siene is a famous river that runs through Paris. Unfortunately though, it is common for the river to become contaminated with various bacteria as the city's ancient sewage and pluming systems are not adequate to prevent 100% of all contamination. Michel was representing Belgium at the games. What makes matters worse in this case is that she was not the only one effected. The entire team, which consists of four people, were forced to withdraw from the triathlon due to her illness.
Furthermore, Claire is not the only athlete to get sick at the games after swimming in the Seine. Swiss competitor Adrien Briffod was also forced to withdraw from competitions after he got a GI infection, most likely from contamination in the river. The following posts have been translated from Spanish.
This is truly a shocking development at the Olympic games. These athletes often spend their entire lives preparing for these moments. The IOC should have tested the water in the river to make sure that is was safe for the competitors prior to the games. Hopefully, Claire Michel and all the other athletes effected by this will be able to compete again at the 2028 games to give themselves a chance at a medal.