Public health officials are investigating an outbreak of a rare parasitic illness linked to a popular petting farm in the Vale of Glamorgan, after 74 people fell ill, including a four-year-old boy who was hospitalised while on a family holiday in Spain.

Public Health Wales confirmed the outbreak of cryptosporidium is connected to visits in April to Cowbridge Farm Shop at Marlborough Grange Farm. Sixteen people have required hospital treatment. The farm has voluntarily suspended petting and feeding activities and is cooperating with the investigation. Cryptosporidium is a parasite commonly spread through contact with infected animals or contaminated water.

It causes cryptosporidiosis, an illness with symptoms including severe diarrhoea, stomach cramps, vomiting, and fever.

While most cases resolve without treatment, the infection can be more serious in young children and those with weakened immune systems.

One affected family, from Bridgend, say their four-year-old son Michael became seriously unwell just days after visiting the farm with his grandmother.

Parents Gareth Carpenter and Kate Wiejak said he first showed symptoms, diarrhoea and a fever, while on a family holiday in Málaga on April 14.

Gareth said: "He was fine when we boarded the plane. We had no idea anything was wrong."

As his condition worsened, the family rushed him to a private hospital, where he was diagnosed with a serious infection and admitted for three days. The €5,000 (£4,229) bill was later claimed through travel insurance.

Upon returning to Wales, Michael’s GP confirmed he had cryptosporidium. Gareth was later contacted by PHW, who told him multiple other cases had been linked to the same farm visit. Both parents also experienced milder symptoms.

"We never imagined a simple petting zoo visit could lead to this," said Kate. "It was terrifying."

PHW is urging anyone who visited the farm and is experiencing symptoms to contact their GP or NHS 111.

They also stress the importance of handwashing, especially after animal contact, to prevent the spread of the infection.

Su Mably, consultant in health protection for Public Health Wales, said: "We are continuing to work with our partners to investigate this outbreak.

"Although cryptosporidium infection is usually mild and clears up on its own, it can cause more serious illness in young children and people with weakened immune systems.

"If you visited the farm and feel unwell, please contact your GP or call NHS 111.

"It is possible for this infection to be passed on from one person to another, for example if someone is caring for a family member who is unwell.

"It is important to protect yourself by washing your hands well, particularly before preparing food."