| Parasite | Defin. host | Intermediate host | Important reservoir of virus | Transmission and pathogenicity |
| Clonorchis sinensis. | Man (cats, dogs and hogs). | 1st, snail (Melania libertina)? and 2d, fish | Man. | Not definitely known. Eating raw fish. Ingestive. Human liver fluke disease. |
| Opisthorchis felineus. | Man (cats and dogs). | 1st, mollusc. 2d, fish. | Cats and dogs. | Man infected by eating raw fish. Ingestive. Liver fluke disease. |
| Fasciolopsis buski. | Man (pig). | Possibly 1st, mollusc. Cercariae encyst on grass. | Hog. | Not definitely known. Intestinal Distomiasis. |
| Heterophyes heterophyes. | Man (dogs and cats). | 1st, probably mollusc. 2d, probably fish. | Dogs and cats. | Not definitely known. Intestinal Distomiasis. |
| Paragonimus ringeri. | Man (dogs, cats and hogs). | 1st, snail. 2d, crab. | Cats, dogs and hogs. | Eating raw crabs containing cercariae. Ingestive. Lung fluke disease. |
| Schistosoma haematobium. | Man. | Snail (Bullinus). | Man (urine). | Bathing or drinking water containing cercariae. Penetrative. Vesical bilharziasis. |
| Schistosoma mansoni. | Man. | Snail (Planorbis). | Man (feces). | Bathing or drinking water containing cercariae. Penetrative. Rectal bilharziasis. |
| Schistosoma japonicum. | Man. | Snail (Blanifordia). | Man (feces) domesticated animals). | Bathing or drinking water containing cercariae. Penetrative. Katayama disease. |
Note.—Rare trematodes of man are (1) Fasciola hepatica. Chiefly disease of sheep. Cercariae from snail (Limnea) encyst on grass. (2) Dicrocoelium lanceatum. Chiefly disease of cattle. (3) Heterophyes nocens. A very small intestinal fluke of man. (4) Metagonimus yokogawai. Another very small intestinal fluke of man. Intermediate hosts: mollusc and gold fish. (5) Echinostoma ilocanum. A rare intestinal fluke of the Philippines. (6) Two genera of Paramphistomidae—Cladorchis and Gastrodiscus. Intestinal flukes.
Helminthic Diseases (Continued). Nematodes
| Parasite | Defin. host | Intermediate host | Important reservoir of virus | Transmission and pathogenicity |
| Filaria bancrofti. | Man. | Mosquito (various species). | Man infected (blood). | Indirect in mosquito. Mature larva penetrates skin. Elephantiasis, etc. |
| Loa loa (F. loa). | Man. | Fly. Species of Chrysops (mangrove flies). | Man infected (blood). | Probably indirect (cyclical) in Chrysops. Probably inoculative. Ocular filariasis, etc. |
| Acanthocheilonema perstans (F. perstans). | Man. | Not definitely known. | Man infected (blood). | Transmission by mosquitoes and ticks suggested. No pathogenicity. |
| Dracunculus medinensis. | Man. | Species of cyclops. | Man infected (subcutaneous tissue). | Larvae enter cyclops. Infected cyclops in drinking water. Ingestive. Guinea worm infection. |
| Onchocerca volvulus (F. volvulus). | Man. | Not definitely known. | Man (blood?). | Possibly Glossina. Subcutaneous tumor and lymphangitis. |
| Strongyloides stercoralis. | Man. | Not required. | Man (feces). | Parasitic filariform larva penetrates skin. Pathogenicity doubtful. |
| Necator americanus and Ancylostoma duodenale. | Man. | Not required. | Man (feces). | Encysted strongyloid larvae penetrate skin. Ancylostomiasis. |
| Trichinella spiralis. | Man (rat and hog). | Hog (man and rat). | Hog (muscle). | Encysted larva in raw or insufficiently cooked pork. Ingestive. Trichinosis. |
Note.—Ascaris, Trichuris and Oxyuris do not require intermediate host. With Ascaris and Trichuris, larva gradually develops in egg passed in faeces. Infection by ingestion of embryo-containing eggs. Embryo-containing eggs contaminate fingers from crushing female Oxyuris in perineal region.
Helminthic Diseases. Cestodes
| Parasite | Defin. host | Intermediate host | Important reservoir of virus | Transmission and pathogenicity |
| Dibothriocephalus latus. | Man. | 1st, cyclops? 2d, fish. | Man (feces), dog and cats. | Eating raw fish containing pleocercoid larvae. Broad Russian tapeworm disease. |
| Hymenolepis nana. | Man. | Not required. | Children (feces). | Man intermediate and definitive host. Ingestive. Dwarf tapeworm disease. |
| Taenia saginata. | Man. | Cattle (ox). | Man (feces). | Eating insufficiently cooked beef containing cysticerci. Ingestive. Beef tapeworm disease. |
| Taenia solium. | Man. | Hog. | Man (feces). | Eating insufficiently cooked pork containing cysticerci. Ingestion. Pork tapeworm disease. |
| Taenia echinococcus. | Dog. | Man, sheep and hogs. | Dog (feces). | Dogs infected at abattoir. Hydatid disease. |
Note.—Rare cestodes of man are (1) Dipylidium caninum. A parasite of the dog with louse or flea as intermediate host. (2) Hymenolepis diminuta. A parasite of rats. Intermediate host in insects. (3) Species of Davainea. Intermediate host possibly cockroach. These cestodes are probably accidental parasites of man.