PHE has received reports of people becoming ill after visiting Gaston Farm, near Slindon in West Sussex from 17 March to 11 April. The initial symptoms of cryptosporidium can take up to two weeks to emerge so PHE is urging people to remain vigilant if they or their family have visited the farm during this period. The gastroenteritis illness is caused by a tiny organism, which in this outbreak is most likely to have resulted from contact with animals shedding the organism in their faeces. The infection can also be easily passed from person to person so it is also important to maintain good hand hygiene around the home, when petting animals and in the preparation of food. PHE would also encourage people to seek medical advice from their GP or NHS 111 if they or a family member becomes unwell.

Dr Kevin Carroll, a consultant with PHE South East's health protection team said:

"Cryptosporidium causes vomiting and diarrhoea in those affected. Anyone suffering from diarrhoea symptoms is being advised not to attend school or childcare settings for 48 hours after recovery. And if you have been diagnosed with cryptosporidium you must not swim until at least two weeks after the symptoms have ended. Cryptosporidium spreads easily in swimming pools because it is not killed by chlorine used to treat the water and you may continue to excrete cryptosporidium for up to two weeks after you have recovered.

"Cryptosporidium is highly infectious so as with all gastrointestinal illness it is important to be scrupulously clean around your home. Clean toilet seats, toilet bowls, flush handles, taps and wash hand basins after use. Make sure all members of your household wash their hands thoroughly with soap and hot water after going to the toilet and after handling soiled clothing or bedding. Make sure that everyone has their own towel and that they do not use anybody else's. Wash all soiled clothes and linen on as hot a machine wash as possible.

"Particular care needs to be taken when preparing food to avoid further infection and should ensure all meat is thoroughly cooked and fruit and salad items are washed before eating. It is vital to wash hands thoroughly using liquid soap and warm running water after using the toilet, before and after handling food and after contact with any animals and pets.

"Anyone who is concerned about vomiting and diarrhoea symptoms should phone NHS 111 or your GP for advice."

PHE and West Sussex County Council have circulated information to schools advising on symptoms and actions to take to prevent further infection.

The farm is assisting PHE and remains closed to visitors. If the public visit farms they should ensure they always wash their hands with soap and hot water (not hand gels) after petting animals.

Residents can find more information at Public Health England .