HistorySarcocystidae: A family of parasitic organisms in the order EIMERIIDAE. They form tissue-cysts in their intermediate hosts, ultimately leading to pathogenesis in the final hosts that includes various mammals (including humans) and birds. The most important genera include NEOSPORA; SARCOCYSTIS; and TOXOPLASMA.Muscidae: A family of the order DIPTERA with over 700 species. Important species that may be mechanical vectors of disease include Musca domesticus (HOUSEFLIES), Musca autumnalis (face fly), Stomoxys calcitrans (stable fly), Haematobia irritans (horn fly) and Fannia spp.Parasitic Diseases: Infections or infestations with parasitic organisms. They are often contracted through contact with an intermediate vector, but may occur as the result of direct exposure.Onchocerciasis: Infection with nematodes of the genus ONCHOCERCA. Characteristics include the presence of firm subcutaneous nodules filled with adult worms, PRURITUS, and ocular lesions.Houseflies: Flies of the species Musca domestica (family MUSCIDAE), which infest human habitations throughout the world and often act as carriers of pathogenic organisms.Helminthiasis: Infestation with parasitic worms of the helminth class.ArtiodactylaDiptera: An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).Filariasis: Infections with nematodes of the superfamily FILARIOIDEA. The presence of living worms in the body is mainly asymptomatic but the death of adult worms leads to granulomatous inflammation and permanent fibrosis. Organisms of the genus Elaeophora infect wild elk and domestic sheep causing ischemic necrosis of the brain, blindness, and dermatosis of the face.Paragonimiasis: Infection with TREMATODA of the genus PARAGONIMUS.Opisthorchis: A genus of trematode liver flukes of the family Opisthorchidae. It consists of the following species: O. felineus, O. noverca (Amphimerus noverca), and O. viverrini. The intermediate hosts are snails, fish, and AMPHIBIANS.Strongyloidiasis: Infection with nematodes of the genus STRONGYLOIDES. The presence of larvae may produce pneumonitis and the presence of adult worms in the intestine could lead to moderate to severe diarrhea.Coccidiosis: Protozoan infection found in animals and man. It is caused by several different genera of COCCIDIA.Trichuriasis: Infection with nematodes of the genus TRICHURIS, formerly called Trichocephalus.Intestinal Diseases, Parasitic: Infections of the INTESTINES with PARASITES, commonly involving PARASITIC WORMS. Infections with roundworms (NEMATODE INFECTIONS) and tapeworms (CESTODE INFECTIONS) are also known as HELMINTHIASIS.Clonorchis sinensis: A species of trematode flukes of the family Opisthorchidae. Many authorities consider this genus belonging to Opisthorchis. It is common in China and other Asiatic countries. Snails and fish are the intermediate hosts.Giardiasis: An infection of the SMALL INTESTINE caused by the flagellated protozoan GIARDIA LAMBLIA. It is spread via contaminated food and water and by direct person-to-person contact.Echinococcus: A genus of very small TAPEWORMS, in the family Taeniidae. The adult form is found in various CARNIVORA but not humans. The larval form is seen in humans under certain epidemiologic circumstances.