Brits were today warned of a gruesome diarrhoea-causing parasite after the UK logged its largest ever outbreak this year. 

More than 770 adults and children were struck down with cryptosporidium, an infection that can pass between animals and humans, as well as from human to human, also causes stomach cramps, vomiting and in rarer cases blood in stools. 

Two other separate outbreaks since 2023 have also seen a further 700 people battling the microscopic bug, health chiefs said. 

Dozens were left suffering bouts of illness so severe they required hospital treatment. 

Officials investigating the unusual clusters of cases believe all three were linked to petting farms which offer cuddles with lambs. 

People can get infected with cryptosporidium via contact with infected faeces which they then accidentally ingest by not washing hands thoroughly. 

This can be direct contact from an infected animal or person, or from contaminated surfaces like farm gates or the bottom of shoes. 

Infected people can shed up to 100million cryptosporidium germs in a single bowel movement, according to the US Centers for Disease Control and Prevention (CDC).

Swallowing just ten of these germs is enough to get ill. 

The outbreak involving 775 Brits is thought to be the largest of its kind recorded in England. 

The two other incidents affected 264 and 482 people respectively, according to the UK Health Security Agency (UKHSA). 

It affected mainly women aged 18 to 48 and children under the age of 16 who had admitted to cuddling and feeding lambs. At least 75 Brits were hospitalised.  

Environmental investigators found inadequate infection prevention and control practices, including concerns regarding handwashing facilities, animal health, animal handling and feeding, and staff preparedness. 

Food was also served in or close to where animals were being handled. 

The authorities did not share which month or where the incidents occurred. 

The fresh UKHSA data was presented at the European Scientific Conference on Applied Infectious Disease Epidemiology in Stockholm. 

Earlier this year Sophie Enright, 14, from Hollywood, near Birmingham is one of those who reported symptoms after her farm visit. 

She became ill on April 9 coming down with diarrhoea, stomach cramps and vomiting six days after she visited 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 suffer as she missed so much school. 

According to the UKHSA, people visiting farms should take precautions to protect themselves from infection including checking there are good hand-washing facilities at the farm with hot water, soap and paper towels.

Children and their supervisors should wash their hands carefully after touching the animals and other farm objects and especially before eating or drinking.

Children should not eat or drink or put their fingers in their mouths whilst close to animals and before washing their hands. 

If possible, visitors should clean shoes and pushchair wheels before leaving the farm and wash hands immediately after cleaning is complete.

 For most people, cryptosporidiosis — the technical name for the infection — is mild.

It typically clears on its own without any treatment within a few days or weeks.

However, for vulnerable people, like those with weakened immune systems and the elderly or patients undergoing cancer treatment, it can be more serious.

Some of the symptoms, such as abdominal pain and blood in the stools, may be particularly anxiety-provoking as they mimic the signs of bowel cancer, which is known to be on the rise.  

Due to the bug's highly infectious nature people with symptoms such as diarrhoea and vomiting are told to stay off work or school until they have been free from these symptoms for at least 48 hours.

Victims can also experience periods of false hope where their symptoms clear for a few days, making them believe they are finally over the infection, only for it to return. 

Most people with cryptosporidiosis aren't offered treatment and are instead told to drink plenty of fluids and minimise contact with other people while waiting until symptoms pass. 

People are typically infected via contact with faeces containing the parasite, either from humans or animals, that then enters their mouth. 

Risk of water supplies becoming infected is also higher following periods of heavy rainfall and when animals are giving birth, such as the lambing season.

Earlier this year the UKHSA issued a warning about the risk of cryptosporidium infection from farm visits.

In a twist on the classic children's 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 it has crypto.'