Parasitic Worms in Humans

Although most parasitic worms seldom cause symptoms in humans, says the Centers for Disease Control (CDC), chronically infected individuals risk serious health consequences. These worms infest people of all socioeconomic groups, and the CDC estimates that at least a third of the world population harbors them.

Types

• Classified as helminths, the groups of parasite worms infecting humans are tapeworms (cestodes), flukes (trematodes), thorny-headed worms (acanthocephala) and roundworms (nematodes).

Geography

• Parasitic worms flourish in tropical and subtropical climates, where the Centers for Disease Control estimates they kill 500,000 people annually.

Effects

• Adult tapeworms and thorny-headed worms both infect the human gastrointestinal tract. Adult and larval roundworms, however, live not only in the GI tract but in the lypmhatic system, skin tissues and blood. Flukes affect the liver and lungs.

Diseases

• The many varieties of roundworms cause serious diseases including elephantiasis, trichinosis, river blindness and Guinea worm disease. Flukes cause schistosomiasis with liver and lung damage. Tapeworms may cause anemia.

Treatment

• Praziquantel treats flukes. Medendazole, pyrantel albdendazole dieythelcarbamazine and ivermectin treat different roundworms. Pyrantel pamoate treats both thorny-headed worms and some roundworms.