True about cryptosporidium parum -

Cryptosporidium has assumed great impoance as a frequent cause of intractable diarrhoea in AIDS patients. It can lead to acute self-limited diarrhoea in previously healthy persons and chronic life-threatening diarrhoea in immunocompromised subjects.Infection is acquired by ingesting the oocyst in contaminated food or drink.Infection in previously healthy persons may be asymptomatic or cause a sef-limited febrile illness with watery diarrhoea. It can also cause childhood and traveller's diarrhoea, as well as water-borne outbreaks. But in the HIV infected and other immunodeficient persons, infection leads to severe protracted diarrhoea, fever and emaciation. In AIDS, the parasite may invade the bronchial and biliary tracts and can be demonstrated in sputum.Diagnosis is made by demonstration of the oocyst in feces. With Jenner-Giemsa stain, the oocysts in faeces smears appear as blue spherical bodies containing a few eosinophilic granules. By cold Ziehl-Neelsen technique, the internal structures appear acid fast