Elephantiasis is caused due to infection by

The filarial worms Wuchereria (W. bancrofti and W. malayi) cause elephantiasis or filariasis, a slowly increasing chronic inflammation of the organs in which they dwell for many years, usually the lymphatic vessels of the lower limbs. The pathogens are transmitted to a healthy person through the bites of female mosquito vectors.

Amoebiasis is caused by the protozoan parasite Entamoeba histolytica, which lives in the human large intestine.

Ascariasis is caused by the intestinal parasite Ascaris.

Prion illnesses are caused by prion infections, which are caused by a misfolded version of a normal host protein called prion protein.