Cryptosporidiosis

Cryptosporidiosis is the commonest protozoal cause of diarrhoea in the UK. Two species, Cryptosporidium hominis and Cryptosporidium parvum account for the majority cases.

Cryptosporidiosis is more common in immunocompromised patients (e.g. HIV) and young children.

Features

• watery diarrhoea
• abdominal cramps
• fever
• in immunocompromised patients, the entire gastrointestinal tract may be affected resulting in complications such as sclerosing cholangitis and pancreatitis

Diagnosis

• stool: modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts (oocytes) of Cryptosporidium

Management

• is largely supportive for immunocompetent patients
• if the patient has HIV and is not on antiretroviral therapy then this should be started and often will be enough to resolve the infection
• nitazoxanide may be used for immunocompromised patients
• rifaximin is also sometimes used for immunocompromised patients/patients with severe disease