Page:Tropical Diseases.djvu/892

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836
NEMATODES
[CHAP.

Personal cleanliness and the use of some form of foot-covering during the wet season, together with the prophylactic measures for ankylostomiasis already mentioned, are the special preventive means indicated as against this disease. As regards treatment, antiseptic foot-baths and some soothing ointment are indicated.

ŒSOPHAGOSTOMUM APIOSTOMUM, Willach, 1891.

Synonym.Œ. brumpti, Railliet and Henry, 1905.

History.— The occurrence in man of this parasitic nematode was discovered by Brumpt, in 1902, at the post-mortem of a thirty-year-old Pouma negro on the river Omo, Africa. Six immature females were found within cyst-like nodules in the wall of the cæcum and colon. Subsequently the same parasite was found by Leiper in natives from northern Nigeria. Johnson found that 4 per cent, of the prisoners in Zungeru jail were infected with the same helminth. We know already of a number of species of the same genus occurring in the Quadrumana. Œ. apiostomum has been found in the gorilla, in the orang-outang, in the chimpanzee, and in various monkeys belonging to the genera Cercopithecus, Cynocephalus, and Macacus; in these, if the infection is severe, it gives rise to dysenteric symptoms.

The parasite.The young females found by Brumpt varied in length from 8.5 to 10.2 mm. and presented a maximum breadth of 295 to 325 μ. The cuticle is transversely striated; the anterior extremity exhibits the ovoid cuticular expansion characteristic of the genus, limited anteriorly by a salient oral ring (oral vestibule), and posteriorly by a constriction which is especially marked on the ventral surface and 200 μ. distant from the oral vestibule. The posterior extremity of the female worm tapers gradually to a caudal point slightly bent dorsally. The male has a terminal bursa similar to that of the Ankylostomum duodenale, but differs in that the trunk of the dorsal ray bifurcates, some distance from the bursal edge, into two branches forming a horseshoe-shaped structure, each limb of which gives off a short lateral horn near its base. The oral vestibule is provided with a crown of twelve sharp chitinous plates directed forwards and inwards, and bears six papillæ, two lateral and four submedian. The œsophagus is club-shaped and measures 470- 500 μ in length by 150 μ in its widest diameter. Anteriorly, it