Public Health Wales, Torfaen County Borough Council and Monmouthshire County Council are continuing to investigate an outbreak of cryptosporidium associated with Coleg Gwent’s farm in Usk.

Seven people have now tested positive for cryptosporidium and 16 others are under investigation after regular attendance at the farm or contact with those who have.

Cryptosporidium is a parasite that is very common in young farm animals and can easily be passed to people who come into contact with those animals. It causes watery diarrhoea, stomach pain, nausea and vomiting, and can last for up to a month. Healthy people will usually make a full recovery.

Heather Lewis, Consultant in Health Protection for Public Health Wales, said: "We are continuing to work with Coleg Gwent, who have written to all students who may have been on the farm in March.

“As a precaution, Coleg Gwent have also cancelled a series of open days which were due to take place with invited primary schools between April 12-15 and have put in place a number of recommended control measures which include limiting college students’ access to animals when they return next week.”

Good hand washing after coming into contact with farm animals, their bedding or dirty equipment including clothing is of the utmost importance in preventing infection with cryptosporidium.

There is no reason for anyone to avoid visiting petting farms as long as they ensure that anyone who has touched animals, thoroughly washes their hands with hot water and soap immediately afterwards and before eating. Hand sanitizers/alcohol gels should not be solely relied upon.

Cryptosporidium maybe acquired by four main routes: from other people, from animals and their faeces, from untreated drinking water contaminated by either agricultural or human sewage sources, and from swimming in contaminated water.

GPs in the Gwent area have been advised of the outbreak and asked to be alert to possible cases of diarrhoea or vomiting in people.

Anyone who is unwell with gastrointestinal symptoms is advised to contact their GP or NHS Direct Wales on 0845 46 47.

People who are unwell with vomiting or diarrhoea should not return to work or school for 48 hours after their symptoms have stopped.

More information on cryptosporidium is available from the Public Health Wales website at: http://www.wales.nhs.uk/sitesplus/888/page/44044