Olympic swimmer gets sick after Seine River swim, prompting Belgium to withdraw from triathlon

Belgian Claire Michel pictured in action during the women's individual triathlon race at the Paris 2024 Olympic Games, on Wednesday 31 July 2024 in Paris, France. The Games of the XXXIII Olympiad are taking place in Paris from 26 July to 11 August. T

An Olympic athlete who swam in the Seine River in Paris has fallen ill, forcing Belgium's Olympic committee to withdraw its team from the mixed relay triathlon. 

The Interfederal Committee said in a statement that  Claire Michel, who competed in the women's triathlon Wednesday, "is unfortunately ill and will have to withdraw from the competition." 

Paris 2024 organizers had no immediate statement.

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The mixed relay triathlon is scheduled to take place Monday, with the swim portion of the competition slated for the Seine as well. The statement did not elaborate on Michel's illness but it comes after concerns over the river's water quality. Organizers had said that water quality tests done the day of the individual triathlon races showed "very good" bacteria levels.

Daily water quality tests measure levels of the fecal bacteria, including E. coli, in the Seine’s waters. World Triathlon’s water safety guidelines and a 2006 European Union directive assign qualitative values to a range of E. coli levels.

Under World Triathlon’s guidelines, E. coli levels up to 1,000 colony-forming units per 100 milliliters can be considered "good" and can allow competitions to go forward.

World Triathlon’s medical committee said it considers water quality analysis, sanitary inspection and the weather forecast when determining whether to go forward with a race. The decisions are made at early morning meetings on the day of the event.

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The Belgian committee said it "hopes that lessons will be learned for future triathlon competitions at the Olympic Games. We are thinking here of the guarantee of training days, competition days and the competition format, which must be clarified in advance and ensure that there is no uncertainty for the athletes, entourage and supporters."

Swiss officials said Saturday that triathlete Adrien Briffod, who also competed in the Seine on Wednesday, fell ill with a stomach infection. But they said it was "impossible to say" whether it was linked to the swim and that the other delegations told them none of their triathletes had reported stomach problems.

Swiss officials said in an update Sunday that Simon Westermann, who had been tapped to replace Briffod, also had to withdraw because of a gastrointestinal infection. Westermann had not participated in any swims in the Seine, the statement said. The Swiss team still planned to compete in the mixed relay Monday.

Norwegian triathlete Vetle Bergsvik Thorn got sick a day after competing in the men’s triathlon. Thorn told Norwegian broadcaster NRK that he woke up the next day with an upset stomach and was vomiting but thought that the likely cause was food poisoning. He said he felt better later that day and was planning on competing again in the mixed relay scheduled for Monday.

Arild Tveiten, the sports director of the Norwegian Triathlon Federation, said the cause of Thorn’s illness was unclear.

"We’re thinking what everyone is thinking: that it’s probably the river. But we don’t know. It could be the river, it could be the chicken," Tveiten told NRK. "The doctor is leaning toward the possibility of food poisoning. That’s what the symptoms suggest."

The Associated Press contributed to this report. This story was reported from Los Angeles.