As SwimSwam has extensively reported, a significant portion of Team USA fell ill in the lead-up to the 2025 World Championships while training at the camp in Phuket, Thailand.
On July 22, SwimSwam first reported concerns of food poisoning at the team’s training camp at Thanyapura Phuket. The following day, a coach with an athlete on the team described the illness as affecting “almost half” of the roster. Sources close to Team USA later confirmed to SwimSwam that about 10 U.S. athletes were too sick to travel to Singapore with the rest of the team. Originally, all swimmers were scheduled to travel together on July 22.
USA Swimming has now broken its silence on the issue, citing “acute gastroenteritis” as the illness impacting many swimmers.
While food poisoning was initially suspected, the continued onset of illness among swimmers after arriving in Singapore suggested otherwise.
Acute gastroenteritis is an inflammation of the stomach and intestines caused by viruses, bacteria, or parasites. This differs from food poisoning, which usually results from eating contaminated food or drink. While the causes aren’t always the same, treatment for both is very similar.
It was reported during today’s NBC broadcast that some Team USA swimmers required hospital treatment, with several needing intravenous (IV) fluids.
Multiple sources close to the American team have confirmed to SwimSwam that many swimmers missed several training sessions leading up to the meet, with some unable to enter the water for several days. At this point, reportedly only a “select few” members of the team have avoided any symptoms.
Although some overall performance impact was expected following the initial news on July 22, many were still shocked when multiple swimmers withdrew from events on day one of competition. Reigning Olympic champion Torri Huske withdrew from the 100 butterfly, Claire Weinstein pulled out of the 400 freestyle, and Gretchen Walsh dropped out of the 4×100 freestyle relay just minutes after finishing the 100 fly semifinal, where she had qualified for the final in a tie for first place.
It is important to note that teams are not allowed to change their relay lineup once a finals session has started. The fact that Walsh’s withdrawal was approved strongly indicates a health-related reason.
Walsh still appears on the start list for tomorrow’s 100 fly final despite pulling out of the relay tonight. She is also entered in the 50 free, 100 free, 50 fly, and potentially the mixed 4×100 free relay, mixed 4×100 medley relay, and women’s 4×100 medley relay.
Huske is expected to swim the 50 and 100 free, as well as potentially the same three relays as Walsh. She is also listed for the 4×200 free relay, though her participation in that event is considered unlikely due to the illness.
Weinstein has the 200 and 800 free events remaining, along with the 4×200 free relay.
Major illnesses have affected swimmers at other global meets in recent years. A diarrhea outbreak impacted numerous athletes at the 2019 Worlds in Gwangju, and a wave of COVID-19 cases disrupted the Paris Olympics last year. While not uncommon, these situations often lead to significant competitive consequences, as appears to be the case again in Singapore.

If asked whether to have another training camp in Thailand, I’d say Phuket. Not the city but the exclamation!
So the US have finally come clean and admitted it’s gastroenteritis . A BIG THANKYOU USA for entering the country without consideration for other athletes competing countries and putting them at risk . Tell me … which box did you all tick on your SG arrival card health declaration ???
Poor form US team management!!
Good luck to all the swimmers competing along side a US swimmer… STAY SAFE !!
Virology 101: Gastroenteritis is not passed by casual contact. And in a chlorinated environment?
Come on
Addendum: wash your hands
Jett and Hobson seem to be ok.
We know that the athletes are trying to do their best and that no one wanted to be sick…but everyone on the team…from the medical staff, the coaches and the athletes need to accept that they made a mistake by not being careful and they need to have a bit more foresight going forward.
They said it’s viral. Not sure how you avoid that.
Don’t go to a place where norovirus is endemic
So everywhere?
It’s not endemic in Antarctica
I suppose. Good swimming facilities in Antarctica?
Having been in and around USA teams and camps for the better part of last 20 years, I will say the camp mentality has shifted from training camp, race prep, lockdown mentality to pre-meet relaxation, we’ve earned it, happy swimmers swim faster mentality. Meehan has to get a hold of this mentality and reel it in a little.
When I think about these overseas staging camps—Croatia and Thailand being the two worst examples—I question who they are for. It seems to me that these locations are selected at least in part because of the luxury experiences available for swimmers. They photograph well. They’re cool for fans to like online and athletes to share.
I understand wanting to provide exclusive experiences for the swimmers lucky enough to make these international teams. However, perhaps USA Swimming should be funding these trips after competition, not before.
I know domestic staging camps have their drawbacks. Swimmers didn’t seem to love them for Tokyo or Rio in 2016. I wonder if the calculus starts to change after this year.
I don’t… Read more »
Pre-meet / team camps should absolutely be domestic …. then travel 5-6 days before the actual meet (for the time adjustment and long flight) and then finish up on-site.
USA is #2!!
Let’s make AAU the governing body. USA Swimming has ZERO competent leadership. People need to stop throwing good money after bad and slapping lipstick on a pig!
I remember back-in-the-day getting AAU age group time-standard patches from the coaches in a little ceremony after the first practice following a meet. I was the first one on our park district team to hit a AA standard. My 9-year-old face was beaming ear to ear when I was called in front of the team for that.