Victoria’s health department says at least 260 festival goers have reported gastroenteritis symptoms after attending a dance music festival, with authorities urging anyone showing signs of shigellosis to be tested.

Those who attended the Esoteric festival in Donald on 8-12 March have been warned that the Shigella bacteria had been detected in a number of those with gastroenteritis. Symptoms could take up to a week to emerge after exposure.

The highly contagious bacterial infection causes the acute onset of diarrhoea, nausea, vomiting, stomach cramps and fever. It is spread by the foecal-oral route or contaminated food.

It could also be transmitted during sexual contact, health authorities said.

Preliminary results suggest the outbreak was caused by an antimicrobial resistant strain of Shigella and would not respond to antibiotics.

“If you attended or worked at the Esoteric festival last weekend and have gastro symptoms, you may have Shigella and be at risk of spreading it,” a Victorian health department spokesperson said.

“We’re asking that you please seek medical care and get a test for Shigella, and not return to work until 48 hours after symptoms resolve.”

They said that those who had the illness and work in food handling, with children, or in aged care should only return to work if they have received a negative test result and have had no symptoms for 48 hours.

Patrons and staff who were returning to locations within Victoria and interstate may develop symptoms in the coming days, authorities warned.

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Dr Rebekah Hoffman, chair of the New South Wales and ACT branch of the Royal Australian College of General Practitioners, said Shigella was “really uncommon” in Australia.

“Gastroenteritis is usually viral, not bacterial. When you put lots of people together and they don’t have the best hand hygiene, Shigella is more likely to be spread,” she said.

“You get really sick from it. We really worry about dehydration and you might be sick enough to have blood and mucus in your stool as well. It is more than the usual gastro.”

Symptoms last around a week, she said, but “you’ll feel rubbish for a few weeks afterwards”.

Anyone with symptoms has been encouraged to stay hydrated and practise good hand hygiene.

Those who attended the festival and work with elderly people or children should be particularly vigilant, even if not showing any symptoms, she said, adding that anyone who has had gastroenteritis should avoid swimming pools for two weeks after symptoms clear.

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