Postrenal transplant patient presents with diarrhoea after 3 months; it was showing organism measuring 2-6 micron meter and kinoyn stain positive. Most likely it is caused by:

Ans. d. Cryptosporidium hominisOppounistic infections are extremely common post-transplant in the period staing from 1 month post-transplant to 6 months post-transplant.Clostridium difficle is usually seen within 1 month post-transplant because of profound antibiotic use.Kinoyn stain (Modified acid fast) positivity rules out Balantidium.Now it is between cryptosporidium vs cycloisospora. Size (smaller i.e., 2-6 microns) tells us that the organism is undoubtedly cryptosporidium hominis (previously parvum).