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Cryptosporidium

What is cryptosporidium?

Cryptosporidium species are protozoan parasites that infect the gastrointestinal tract of a wide range of vertebrate hosts. 

Pathogenicity varies with the species of parasite (nine are recognised) as well as with the type, age and immune status of the host. Two cryptosporidium species in equal measure are responsible for most human infections in the UK, namely C. parvum and C. hominis.

Clinical signs

C. parvum can be found in most livestock species as well as in wildlife while C. hominis is regarded as a strictly human parasite rarely seen in animals. 

In animals, cryptosporidiosis causes diarrhoea, anorexia and weight loss although sub-clinical infection occurs in lambs and older animals. 

In humans

Cryptosporidiosis in humans is usually sporadic but can occur as outbreaks. People become infected through direct contact with other infected people, animals or faeces or indirectly through contaminated drinking water, swimming pools and possibly food.