whipworm trichuris trichiura is parasitic helminthic nematode

animal ascariasis ascaris biology blood cestode colon digestive disease egg flat fluke helminth hookworm human illness infection internal intestinal intestine intestines larva liver medical medicine microscope microscopy nematode parasite parasitic pinworm research round roundworm schistosomiasis science taenia tapeworm tract trematoda trichiura trichuriasis trichuridae trichuris whipworm white worm