27 new cases have been confirmed in a cryptosporidium outbreak linked to a farm shop in Cowbridge.
Public health officials say at least 16 people were taken to hospital for at least one night as a result.
A total of 74 cases have been confirmed - and the number of hospital patients is expected to grow in the next week due to the incubation period.
A specialist outbreak control team met on Thursday to discuss the outbreak, linked to feeding and petting activities with young calves and lambs at Marlborough Grange Farm, which have since been stopped voluntarily.
Su Mably, a health protection consultant at Public Health Wales (PHW), said: “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. It is important to protect yourself by washing your hands well, particularly before preparing food."
Cryptosporidium is a parasite that can cause gastrointestinal illness. It is often linked to contact with animals, especially young farm animals such as calves and lambs.
It can last for up to a fortnight and symptoms usually begin around two to ten days after contact.
The main symptoms of cryptosporidium include watery diarrhoeam, stomach pains or cramps, nausea or vomiting, a loss of appetite and weight loss and mild fever.
Public Health Wales says it advises anyone visiting farms to follow good hygiene practice, such as washing your hands throughly after touching animals, boots or clothing and before eating or drinking.
They advise parents to supervise children closely to ensure they wash their hands properly while pregnant women should take particular care and avoid contact with newborn lambs during the lambing season.
PHW added that it’s continuing to work alongside Vale of Glamorgan Council and the Cardiff and Vale University Health Board as part of their investigation into the outbreak.
The owners of the farm shop have made no public comment.
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