''Elaeophora poeli'' is a parasitic

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

found in the aorta, and sometimes the heart, of various cattle throughout Asia, and in parts of Africa. It is a large nematode, with males measuring 45–70 mm long and 200-260 μm wide, and females 40–300 mm long and 350 μm wide. Microfilariae are 340-346 μm long and 7.0-7.5 μm wide. Despite the fact that it lives in nodules ( aneurysms) in the walls of the aorta and heart, apparent clinical symptoms of ''E. poeli'' infestation are seldom reported.

Discovery and nomenclature

This species was first described from Water buffalo in 1879, and named ''Filaria poeli''. In 1912, it was transferred to the newly erected genus ''Elaeophora'' Railliet and Henry 1912. In 1938, a detailed redescription of ''E. poeli'' was published. In that study, ''E. poeli'' was determined to be the same animal that previous authors had referred to as ''Filaria blini'' and ''Filaria haemophila'', both isolated from Water buffalo aortas.

Hosts and geographic distribution

''E. poeli'' has been found in several species of cattle: African buffalo (''Syncerus caffer''), Carabao or Water buffalo (''Bubalus bubalis''), and Zebu (''Bos primigenius indicus''). The geographic distribution of this species includes several Asian and African nations: Democratic Republic of Congo, India, Indonesia, Malaysia, Mozambique, the Philippines, Tanzania, Thailand, Uganda, and Vietnam.

Life cycle

The life cycle of ''E. poeli'' is not known. The adults usually live attached to the inner walls of the aorta. They make aneurysmal (i.e. bulging) nodules in the wall of the aorta, which can be up to 2 cm in diameter. The male lives curled up inside the nodule, while the female lives with its head in the nodule and its body free in the lumen (interior space) of the aorta. Presumably the female sheds the offspring (

microfilaria ::''Microfilaria may also refer to an informal "collective group" genus name, proposed by Cobbold in 1882. While a convenient category for newly discovered microfilariae which can not be assigned to a known species because the adults are unknown, ...

e) directly into the host's bloodstream. Adults have also been found in nodules on the epicardium of the heart.

Prevalence

The percentage of animals found to be infested in large-scale slaughterhouse studies range from 1.7% in Tanzanian Zebu (''Bos primigenius indicus'') to over 60% in Philippine ''Bubalus bubalis''. A study of free-ranging buffalo in Queen Elizabeth National Park, Uganda, yielded a 55% infestation rate.

Clinical significance

The nodules where the filariae reside (as described above) are aneurysms - bulges in the aorta wall - which could conceivably rupture. Corrugated and migratory tract lesions on the inner wall of the aorta and fibrin strands attached to the nodules have also been described. The latter study found narrowing of the aorta down to 1/3 of its usual diameter in some cases. Despite the presence of nodules 2-cm in diameter on aorta walls and heart tissue, and narrowing of the aorta, almost all studies of ''E. poeli'' infestation mention a lack of obvious clinical symptoms in infested individuals. One study found a strong correlation between infestation and visceral pleurisy (inflammation of the membrane that surrounds the lungs).Ferreira, M.L.P., J.L.N. Petisca, and V. Jurasek (1983) Alguns aspectos de patogenia de ''Elaeophora poeli'' em búfalos (''Syncerus caffer'') em Moçambique / Some aspects of pathogenesis of ''Elaeophora poeli'' in buffaloes (''Syncerus caffer'') in Mozambique." ''Repositório de Trabalhos do Laboratôrio Nacional de Investigação Veterinária'' 15:11-16, 11 plates.

References

{{Taxonbar, from=Q5353124 Spirurida Parasitic nematodes of mammals Veterinary helminthology Bovine diseases Nematodes described in 1879