Cryptosporidiosis is a disease usually caused by the parasites Cryptosporidium hominis and C. parvum. It is most commonly seen in children aged between 1 and 5 years. People with weak immune systems are likely to be more seriously affected. The most common symptom is mild to severe watery diarrhoea.
The parasites are resistant to chlorine. Outbreaks of cryptosporidiosis have been linked to drinking or swimming in contaminated water and contact with infected lambs and calves during visits to open farms.
Public Health England (PHE) provides advice on controlling outbreaks of cryptosporidiosis and monitors any outbreak to find the source of the infection.
Manage outbreaks and cases of gastrointestinal infections.