Brugia malayi: A species of parasitic nematode causing Malayan filariasis and having a distribution centering roughly on the Malay peninsula. The life cycle of B. malayi is similar to that of WUCHERERIA BANCROFTI, except that in most areas the principal mosquito vectors belong to the genus Mansonia.Brugia: A filarial worm of Southeast Asia, producing filariasis and elephantiasis in various mammals including man. It was formerly included in the genus WUCHERERIA.Brugia pahangi: A species of parasitic nematode found in man and other mammals. It has been reported from Malaya and East Pakistan and may produce symptoms of tropical eosinophilia.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.Microfilaria: The prelarval stage of Filarioidea in the blood and other tissues of mammals and birds. They are removed from these hosts by blood-sucking insects in which they metamorphose into mature larvae.Elephantiasis, Filarial: Parasitic infestation of the human lymphatic system by WUCHERERIA BANCROFTI or BRUGIA MALAYI. It is also called lymphatic filariasis.Filarioidea: A superfamily of nematodes of the suborder SPIRURINA. Its organisms possess a filiform body and a mouth surrounded by papillae.Wolbachia: A genus of bacteria comprised of a heterogenous group of gram-negative small rods and coccoid forms associated with arthropods. (From Bergey's Manual of Systematic Bacteriology, vol 1, 1984)Helminth Proteins: Proteins found in any species of helminth.Antigens, Helminth: Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.Gerbillinae: A subfamily of the Muridae consisting of several genera including Gerbillus, Rhombomys, Tatera, Meriones, and Psammomys.Wuchereria bancrofti: A white threadlike worm which causes elephantiasis, lymphangitis, and chyluria by interfering with the lymphatic circulation. The microfilaria are found in the circulating blood and are carried by mosquitoes.Antibodies, Helminth: Immunoglobulins produced in a response to HELMINTH ANTIGENS.Dirofilaria immitis: A filarial parasite primarily of dogs but occurring also in foxes, wolves, and humans. The parasite is transmitted by mosquitoes.Dipetalonema: A filarial nematode parasite of mammalian blood with the vector being a tick or small fly.DNA, Helminth: Deoxyribonucleic acid that makes up the genetic material of helminths.Diethylcarbamazine: An anthelmintic used primarily as the citrate in the treatment of filariasis, particularly infestations with Wucheria bancrofti or Loa loa.Murinae: A subfamily in the family MURIDAE, comprising the Old World MICE and RATS.Filaricides: Pharmacological agents destructive to nematodes in the superfamily Filarioidea.RNA, Helminth: Ribonucleic acid in helminths having regulatory and catalytic roles as well as involvement in protein synthesis.Aspartate-tRNA Ligase: An enzyme that activates aspartic acid with its specific transfer RNA. EC 6.1.1.12.Onchocerca: A genus of parasitic nematodes whose organisms live and breed in skin and subcutaneous tissues. Onchocercal microfilariae may also be found in the urine, blood, or sputum.Genome, Helminth: The genetic complement of a helminth (HELMINTHS) as represented in its DNA.Culicidae: A family of the order DIPTERA that comprises the mosquitoes. The larval stages are aquatic, and the adults can be recognized by the characteristic WINGS, ANIMAL venation, the scales along the wing veins, and the long proboscis. Many species are of particular medical importance.Trans-Splicing: The joining of RNA from two different genes. One type of trans-splicing is the "spliced leader" type (primarily found in protozoans such as trypanosomes and in lower invertebrates such as nematodes) which results in the addition of a capped, noncoding, spliced leader sequence to the 5' end of mRNAs. Another type of trans-splicing is the "discontinuous group II introns" type (found in plant/algal chloroplasts and plant mitochondria) which results in the joining of two independently transcribed coding sequences. Both are mechanistically similar to conventional nuclear pre-mRNA cis-splicing. Mammalian cells are also capable of trans-splicing.Genes, Helminth: The functional hereditary units of HELMINTHS.RNA, Spliced Leader: The small RNAs which provide spliced leader sequences, SL1, SL2, SL3, SL4 and SL5 (short sequences which are joined to the 5' ends of pre-mRNAs by TRANS-SPLICING). They are found primarily in primitive eukaryotes (protozoans and nematodes).Nematoda: A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Symbiosis: The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.Caenorhabditis: A genus of small free-living nematodes. Two species, CAENORHABDITIS ELEGANS and C. briggsae are much used in studies of genetics, development, aging, muscle chemistry, and neuroanatomy.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Animal Structures: Organs and other anatomical structures of non-human vertebrate and invertebrate animals.Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.Haemonchus: A genus of parasitic nematode worms which infest the duodenum and stomach of domestic and wild herbivores, which ingest it with the grasses (POACEAE) they eat. Infestation of man is accidental.Aedes: A genus of mosquitoes (CULICIDAE) frequently found in tropical and subtropical regions. YELLOW FEVER and DENGUE are two of the diseases that can be transmitted by species of this genus.Tropical Medicine: The branch of medicine concerned with diseases, mainly of parasitic origin, common in tropical and subtropical regions.Benzothiazoles: Compounds with a benzene ring fused to a thiazole ring.Strongyloides stercoralis: A species of parasitic nematode widely distributed in tropical and subtropical countries. The females and their larvae inhabit the mucosa of the intestinal tract, where they cause ulceration and diarrhea.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.Thiabendazole: 2-Substituted benzimidazole first introduced in 1962. It is active against a variety of nematodes and is the drug of choice for STRONGYLOIDIASIS. It has CENTRAL NERVOUS SYSTEM side effects and hepatototoxic potential. (From Smith and Reynard, Textbook of Pharmacology, 1992, p919)IndiaStrongyloides: A genus of parasitic nematodes widely distributed as intestinal parasites of mammals.Loa: A genus of parasitic nematodes found throughout the rain-forest areas of the Sudan and the basin of the Congo. L. loa inhabits the subcutaneous tissues, which it traverses freely.Onchocerca volvulus: A species of parasitic nematodes widely distributed throughout central Africa and also found in northern South America, southern Mexico, and Guatemala. Its intermediate host and vector is the blackfly or buffalo gnat.Trichostrongyloidea: A superfamily of nematodes. Most are intestinal parasites of ruminants and accidentally in humans. This superfamily includes seven genera: DICTYOCAULUS; HAEMONCHUS; Cooperia, OSTERTAGIA; Nematodirus, TRICHOSTRONGYLUS; and Hyostrongylus.Trichostrongyloidiasis: Infection by roundworms of the superfamily TRICHOSTRONGYLOIDEA, including the genera TRICHOSTRONGYLUS; OSTERTAGIA; Cooperia, HAEMONCHUS; Nematodirus, Hyostrongylus, and DICTYOCAULUS.Ostertagia: A genus of parasitic nematodes occurring in the stomach of ruminants.Ostertagiasis: A disease of herbivorous mammals, particularly cattle and sheep, caused by stomach worms of the genus OSTERTAGIA.Abomasum: The fourth stomach of ruminating animals. It is also called the "true" stomach. It is an elongated pear-shaped sac lying on the floor of the abdomen, on the right-hand side, and roughly between the seventh and twelfth ribs. It leads to the beginning of the small intestine. (From Black's Veterinary Dictionary, 17th ed)Nematode Infections: Infections by nematodes, general or unspecified.Sheep Diseases: Diseases of domestic and mountain sheep of the genus Ovis.