the causative agent echinococcus

ache agent agony ailment anguish bile brain causative cerebral cerebrum colon contagion contamination cyst decease digestion digestive disease disorder distress echinococcosis echinococcus gall helminthiasis helminthic helminthosis hepatic human hydatid ill illness infection infestation intestine invasion large liver lungs medical medicine pain parasite pest reins sickness soreness thick vermin worms