Cases of cryptosporidium, a parasite that primarily infects people through feces contaminated with drinking water, have reached 77.
Most infections are in Devon, but outbreaks have also been reported in Oxfordshire and Worcestershire over the past two months.
The most serious outbreak is linked to faeces-contaminated drinking water in Brixham, Devon, which began earlier this month.
However, dozens more Britons, including children, have fallen seriously ill since late March following outbreaks at pet farms.
And those looking to escape the risk of contracting the parasite this semester by traveling abroad are warned that swimming pools may not be safe either.
Cryptosporidium parasites are protected by a thick layer that allows them to survive even in chlorinated pool water.
Entire streets in Brixham have been infected with victims forced to endure days of agonizing diarrhea and stomach cramps, with one victim even likening them to “childbirth”.
Residents have been forced to boil water for more than a week to make it safe to drink, and some stores have run out of bottled supplies due to panic buying.
The source of the outbreak appears to be a damaged air valve in the water supply line that “may have allowed animal waste or contaminated groundwater to enter the local supply.”
While water contaminated with feces is the classic way people become infected with cryptosporidium, there are other ways you could contract the virus.
One of them is direct contact with infected animals, a fate that potentially appears to have befallen dozens of Britons in recent months.
At least two petting farms, which invite families to cuddle free-range animals such as lambs, have been hit by suspected cryptosporidium outbreaks in the past two months.
More than 80 people are reported to be seeking legal advice after parents and children fell ill at Gannow Farm, in Worcestershire, over Easter.
Victims of the infection suffered serious gastric illnesses and some even required hospital treatment.
Sophie Enright, 14, from Hollywood, near Birmingham, is one of those who reported symptoms after her visit to the farm.
He became ill on April 9 and suffered diarrhea, stomach cramps and vomiting six days after visiting the farm.
Sophie was eventually diagnosed with cryptosporidium and lost a stone over the course of her illness.
Her mother, Emma Cleverley, 38, said she was worried her daughter’s exam results would be affected because she missed so much school.
Another boy, five-year-old Eli, had to be hospitalized after falling ill with cryptosporidium, and his mother, Kelly Roberts, said “it could have killed him.”
“We came to spend a nice family day and left with a bug that could have killed him,” he told the newspaper. Sun.
She added: “Seeing my son hooked up to an IV, having blood drawn from his arms and not being able to drink water was just horrible.”
The UK Health Security Agency (UKHSA) is investigating the farm which has been closed since the outbreak.
Sophie Enright, 14, (pictured) visited a farm with her mother Emma Cleverley, 38, on April 3 and on April 9 she fell ill with diarrhoea, stomach cramps and vomiting.
Sophie was prescribed anti-nausea medication and medication to relieve her stomach cramps, but four days later her symptoms had not improved.
On Facebook, the farm itself said it took the well-being of its visitors “very seriously” and was working with investigators.
On Facebook, the farm itself said it took the well-being of its visitors “very seriously” and was working with investigators.
He added: “We would like to wish anyone who is unwell a speedy recovery.”
Amy Chappell, from Banbury in Oxfordshire, is another mother whose son fell ill with cryptosporidium and said her daughter Poppy had to spend four days in hospital after a day on a farm during lambing season.
Mrs Chappell said of her daughter’s cryptosporidium infection: ‘She was constantly sick every few minutes and this went on for days.
“After seeing the GP out of hours, I took her to A&E and they admitted her straight away and put her on a drip because she had lost a lot of fluid and gave her anti-nausea medication regularly.
“She was so exhausted and withdrawn she couldn’t even get out of bed to go to the bathroom, it was really worrying for all of us.”
Poppy’s mother added: ‘This has really affected her psychologically.
Amy Chappell, from Banbury, Oxfordshire, said her daughter Poppy became seriously ill and spent four days in hospital after a day on a farm during lambing season.
Tom Bayliss, six, and his sister Grace, two, at Hadsham Farm in Horley, Oxfordshire. It is believed that they transmitted cryptosporidiosis from the lambs.
Hadsham Farm’s lambs were found to have tested negative for cryptosporidiosis, but they closed the lambing event as a precaution.
“She was so sick that now she is very eager to eat because she thinks it will make her sick and she has problems with her digestive system.”
“This has had a huge impact on the whole family – we had no idea how serious this mistake could be.
“We made sure to wash our hands after touching the animals and before eating, and Poppy even wore gloves, but she must have picked it up after that.”
Rebecca Bayliss, another mother, suspects she and her six-year-old son Jake suffered a similar fate after falling ill after visiting Hadsham Farm in Horley.
Her daughter Grace, two, and her husband Tom, 36, who didn’t even attend the birth event, also started having symptoms later at home.
‘It was horrible. We were all really sick. My son lost a lot of weight and was very close to going to the hospital because he was very dehydrated. The only way to get him to drink was to give him still lemonade,” he told MailOnline.
The UKHSA issued a warning about the risk of Cryptosporidium infection on farm visits earlier this month.
The UKHSA issued a warning about the risk of Cryptosporidium infection on farm visits earlier this month.
Residents of Brixham, Boohay, Kingswear, Roseland and north-east Paignton in Devon were asked to boil water as a precaution.
Cryptosporidium is resistant to chlorine, so even swimming in pools is no guarantee against infection (file image)
In a variation on the classic nursery rhyme, the agency wrote on social media: “Mary had a little lamb, its fleece was white as snow.
“But wash your hands and dry them too in case you have cryptocurrencies.”
People can become infected with Cryptosporidium from farm animals through contact with infected feces that they then accidentally ingest by not washing their hands properly.
It can be direct contact with the animal itself or surfaces contaminated with feces, such as farm gates or the soles of shoes.
But as a warning, Brits jumping into these mid-term pools is not a sure way to avoid the parasite.
Cryptosporidium is resistant to chlorine and can survive in swimming pools for up to a week.
People who recover from the infection are urged to avoid swimming for two weeks after their symptoms have resolved, as they may still be contagious.
These infections occur after remnants of dried excrement are washed from an infected person’s anus and enter the water before being swallowed by an unfortunate swimmer.
Infections linked to swimming pool use are believed to have been the cause of the unseasonal outbreak of cryptosporidium in Britain late last year.
At the time, officials investigating the unusual cluster of cases discovered that the only connection between the cases was that dozens of affected Britons had recently traveled to Spain and other Mediterranean countries.
Other possible routes of infection for Cryptosporidium include sharing towels, using swimming pools both in the UK and abroad and preparing food.