''Dirofilaria'' is a

filaria ''Filaria'' is a genus of nematodes belonging to the family Filariidae. The genus has cosmopolitan distribution. Species: *'' Filaria acutiuscula'' *'' Filaria bufonis'' *'' Filaria loliginis'' *'' Filaria martis'' *'' Filaria piscium'' ...

l (

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

-borne) nematode (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, loiasis, and other filariases. Represent ...

. 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 Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

, 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 common raccoon to distinguish it from other species, is a mammal native to North America. It is the largest of the procyonid family, having a body length of , and a body weight of ...

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 (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

es.

Etymology

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

Filarioidea The Filarioidea are a superfamily of highly specialised parasitic nematodes. Species within this superfamily are known as filarial worms or filariae (singular filaria). Infections with parasitic filarial worms cause disease conditions generica ...

. 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 Joseph Mellick Leidy (September 9, 1823 – April 30, 1891) was an American paleontologist, parasitologist and anatomist. Leidy was professor of anatomy at the University of Pennsylvania, later was a professor of natural history at Swarthmore ...

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'' {{Taxonbar, from=Q1994726 Spirurida Secernentea genera