''Dirofilaria'' is a filarial (

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

-borne)

nematode The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...

(roundworm), in the family

Onchocercidae The Onchocercidae are a family of nematodes in the superfamily Filarioidea. This family includes some of the most devastating human parasitic diseases, such as lymphatic filariasis, onchocerciasis, Loa loa filariasis, loiasis, and other Filaria ...

. Some species cause dirofilariasis, a state of parasitic infection, in humans and other animals. There are about 27 species in the genus.Michalski, M. L., et al. (2010). dentification and phylogenetic analysis of ''Dirofilaria ursi'' (Nematoda: Filarioidea) from Wisconsin black bears (''Ursus americanus'') and its ''Wolbachia'' endosymbiont.''Journal of Parasitology'', 96(2), 412-419. These are generally divided into two subgenera, '' Dirofilaria'' and '' Nochtiella''. Some species are well-known parasites, including '' Dirofilaria immitis'', the dog heartworm, '' Dirofilaria repens'', which affects many types of nonhuman mammals, and '' Dirofilaria tenuis'', which usually parasitizes

raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...

s, but can infect humans, as well. Human dirofilariasis is generally caused by ''D. immitis'' and ''D. repens''. The former can cause pulmonary dirofilariasis, which may have no symptoms. Another form of the infection can be characterized by a painful lump under the skin or infection of the eye. The nematodes are spread by

mosquito Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...

es.

Etymology

From Latin ''dīrus'' 'fearful; ominous' + ''fīlum'' 'thread', ''Dirofilaria'' is a genus of nematodes of the superfamily

Filarioidea The Filarioidea are a Taxonomic rank, superfamily of highly Generalist and specialist species, specialised Parasitism, parasitic nematodes. Species within this superfamily are known as filarial worms or filariae (singular filaria). Infections wit ...

. The first known description of ''Dirofilaria'' may have been by Italian nobleman Francesco Birago in 1626 in his Treatise on Hunting: “The dog generates two worms, which are half an arm’s length long and thicker than a finger and red like fire.” Birago erroneously identified the worms as a larval stage of another parasite, '' Dioctophyme renale''. The dog heartworm was named ''Filaria'' by American parasitologist Joseph Leidy in 1856, and the genus was renamed ''Dirofilaria'' by French parasitologists Railliet and Henry in 1911.

Taxonomy

References

''This article uses public domain text from the CDC as cited'' {{Authority control Spirurida Nematodes Parasitic nematodes Rhabditida genera