The United States started its 2025 World titles campaign on the back foot this morning, Olympic champion Torri Huske's withdrawal from the 100m butterfly heats the notable Hobson's Choice decision of the first morning of heats.

As noted in our World Champs Diary on Friday, Huske was one of a large contingent of American swimmers hit by a stomach bug or food poisoning on final-prep-camp in Thailand a week ago. USA Swimming confirmed this morning, without citing numbers, that members of its team had suffered a bout of acute Gastroenteritis, an inflammation of your stomach and intestines brought on by a virus or bacteria. 

Huske, believed to have been among those affected, is said to have dropped the 100m butterfly, her golden Paris 2024 solo event, in favour of being at the best she can be in the final of the 4x100m free relay against defending Australian Dolphins this evening.

We bring you this file an hour after we might have been up and running but for another form of weakness here on day 1 heats: the internet signal in the media tribune means that no live coverage can be worked on with wifi.

Not good enough, it being a World Championships and all that. And so, we're late with our live in an environment more testing than t would be were we to sit home and watch the remote clock. That's not something the sport of swimming should wish for or encourage, for several big reasons when it comes to that key constitutional pledge of World Aquatics: 'to grow aquatics sports'.

Media organisations pay 5 to 20k a head to have reporters, photographers and others work live at the championship venue. In this day and age, speed counts. Fast-functioning internet is an essential work tool. World Aquatics knows that - and yet, we begin a World championships where the media that wishes to file in real time cannot do so while watching the live acton. That should never happen.

The solution so far has been to tell us that the signal cannot be boosted (presumably the unspoken words include 'because we're not spending a penny more on it now and its beyond what we're prepared to do'); so 'use the cabled internet on the tribune'. That means one cable for each row of eight journalists. Again, not really a solution at all.

And, again, it's a World Championships. Professionalism and high standard delivery of work conditions conducive to the environment the media must and does work in these days, are an essential part of hosting the showcase event. The buck stops at the top table of World Aquatics. Perhaps they can find solutions before day 1 finals begin.

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A quick wrap of heats, fuller takes and all qualifiers below:

• Summer McIntosh swims aside World-record pace at the first turn of the 200m medley and then settled into every-management mode to qualify comfortably for the semis of the medley and the final of the 400m freestyle
• Katie Ledecky leads the way in the 400m free heats, on 4:01, with Lani Pallister on 4:02 and McIntosh on 4:03. New Zealand's sub-4-min-club contender Erika Fairweather is out after a DQ for a false start.
• Sam Short and Lukas Märtens led the way into the men's 400m free final on 3:42 and 3:43 respectively
• In that men's 400m free, we witnessed another result of the gastro strike: Luka Mijatovic, 3:59, about 16sec outside his best. It would seem we now know why: he's a member of the USA team, all members of which made it to Singapore and all compete over the coming eight days.
• Gretchen Walsh whistled into the 100m butterfly semis in another class speed to all others, on 55.68. Germany's Angelina Kohler, reigning champion from the 'intercalated' Doha 2024 World titles, is closest, on 56.49.
• Maxime Grousset, of France, set the pace in 22.74 in heat 9 before Canada's Ilya Kharun took heat 10 in 22.85, World short-course champion and record holder Noé Ponti, of Switzerland, through to semis on 22.74 atop heat 11.
• A note on neutrality after the men's 100 breaststroke heats
• USA leads the men's and women's 4x100m freestyle heats.