Drug therapy for helminth infections is difficult since selective toxicity is a problem. Usually rely on dose related selectivity. Since the helminths are smaller than us, a drug can sometimes be given in a low dose that will harm the worm but not kill us. On of the most common drugs used for these infections paralyzes the muscles of worms, but only give us muscle cramping or discomfort. Nematodes Ascaris lumbricoides causes ascaris infections Ascaris is the most common helminth infection in the world.
Humans pick up eggs from the environment.
Invade lung and move up the respiratory tree into the larynx and to the glottis where they get swallowed and back into the intestines. Mature in the intestines and reproduce. Eggs expelled into feces. Symptoms of infection include allergic reaction and inflammatory damage. Sometimes the larvae wander into throat from the glottis instead of being swallowed and going to the intestines.