Transmission via water contaminated with animal wastes. LIke Giardia, the oocysts are resistant to chlorine and must be removed by filtration which sometimes fails. Fecal-oral transmission also occurs. E. Helminthic Diseases 1. Eggs ingested wtih contaminated feed by animals and hatch into a larval form which lodges in the animals muscles.
People get tapeworms from eating undercooked beef, pork or fish.
Worm in intestines doesn't cause much problem. Symptoms mimic a brain tumor 2. Humans become infected from the feces of dogs. Cysts need to be removed surgically. Pinworms - tiny, microscopic worms migrate out of anus to lay eggs, cause intense itching 4.