A genus of trematodes,<unk>  spp.,  commonly known as blood-flukes and bilharzia, cause the most significant infection of humans by flatworms <unk> asis) and are considered by the World Health Organization as second in importance only to malaria, with hundreds of millions infected worldwide. Adult worms parasitize mesenteric blood vessels.  Eggs are passed through urine or feces to fresh water, where larval stages can infect a new host by penetrating the skin.
Schistosoma
Hookworm
Flea
Pinworm
Cestoda
Ringworm
Arthropod
Spirochaete