Part 161

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ASCARIS MYSTAX, the common round-worm of the cat and dog, has been reported as occasionally infesting man. It resembles the former species, but is much smaller, commonly from one to four inches in length, and has the head end furnished with a pair of lateral narrow, wing-like expansions of the integument. It inhabits the small intestine, and when present in man would no doubt induce symptoms like those of the ordinary round-worms which infest him.

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TRIOCEPHALUS DISPAR.--SYNONYMS: Long thread-worm; Whip-worm.

The long thread-worm is a not unfrequent intestinal parasite of man, though rarely observed unless specially sought, as it ordinarily gives rise to little or no disturbance. It is common in England, Southern Europe, and the Orient. Davaine reports that half the cases of persons investigated in Paris were infested with it; it also occurs in this country. It inhabits the lower end of the ileum, the cæcum, and vermiform appendix, and feeds on the intestinal contents. It commonly occurs in small numbers, two or three to a dozen, occasions no evident inconvenience, and is rarely discharged with the evacuations.

The long thread-worm is yellowish-white and cylindrical, with the anterior half or more of the body attenuated in a hair-like manner. The female reaches about two inches in length, has the tail end conical, and the anus subterminal. The male is about two-thirds the length of the former, has the thicker portion of the body enrolled, and the tail end blunt. The eggs are laid in the intestine and discharged with the feces. The subsequent history of the parasite and its mode of infecting man remain unknown.

Only in cases where long thread-worms are numerous do they give rise to trouble. According to Leuckart, Pascal gives as constant symptoms of the presence of large numbers of the parasite, headache, redness of the face, prominence of the eyes, small, irregular, and intermittent pulse, and pains in the lower part of the abdomen.

The usual remedies addressed to the seat-worm and round-worm will most probably be equally applicable to the long thread-worm.

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LEPTODERA STERCORALIS.--SYNONYMS: Anguillula stercoralis; Rhabditis stercoralis.

{955} This is a minute nematode worm recently observed infesting French soldiers in Cochin China. It is about half a line in length, and inhabits the small and large intestine, and also penetrates into the biliary and pancreatic ducts. It occurs in myriads and occasions diarrhoea and dysentery. Another species, Leptodera intestinalis, nearly three times as large, has been noticed in smaller number associated with the former. The eggs of these worms are laid in the intestines, and both together are discharged in multitudes with the feces. They are probably introduced into man by drinking stagnant water, and undergo complete development after passing through the stomach.

It is probable that the remedies employed in the treatment of the familiar seat-worms and round-worms would be equally efficacious in the expulsion of these parasites.

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ANCHYLOSTOMUM DUODENALE.--SYNONYMS: Strongylus duodenalis; Dochmius duodenalis; Sclerostoma duodenale.

This intestinal parasite, first noticed in Milan by Dubini in 1838, is of more dangerous character than any of the nematode worms previously described. In Europe, besides Italy, it was frequently observed among the workmen of the St. Gothard tunnel. It is exceedingly common in Egypt, and Bilharz found it in nearly all his post-mortem examinations of bodies. It probably prevails to a considerable extent in most tropical countries, including the East and West Indies and Brazil. There is also reason to suspect, from the nature of the affection it induces, that it may exist in the Southern States.

The Anchylostomum is a red, cylindrical worm, with the anterior extremity tapering and recurved. The head end, somewhat enlarged, encloses a capacious oral capsule armed with strong hook-like teeth. The caudal extremity of the female ends in a conical point, and the genital aperture is situated behind the middle of the body. The caudal extremity of the male ends in a trilobate pouch, within which projects the bispiculate penis. The female is from five lines to three-fourths of an inch long; the male is about half the size. The eggs are oval and measure 0.05 mm. long.

The worm inhabits the small intestine, especially the duodenum and jejunum, clinging tenaciously to the lining membrane by means of the armed mouth. It penetrates the mucous membrane to the submucous coat, from which it sucks the blood that forms its food. In the position of its attachment it gives rise to little ecchymoses. It often occurs in large numbers, even to hundreds and thousands. The eggs are laid in the intestine and are discharged with the evacuations. Externally, in water, the embryo undergoes development within the egg, and then escapes to lead for some time an independent existence. Subsequently, it is most probable that the worm obtains access to the human stomach by drinking standing water, and completes its development in the intestine.

The Anchylostomum proves to be a prolific source of wasting diseases in tropical countries, and is pernicious to an extent proportioned to the numbers infesting the intestine. By depriving the body of blood it produces a greater or less degree of anæmia. The affection begins very insidiously, and the general nutrition of the body may not be visibly disturbed {956} until a late period. In moderate cases the disease is indicated by general paleness of the skin and mucous membranes, fatigue on slight exertion, and a tendency to palpitations and quickened pulse. In more severe cases there is constantly increasing debility, with increase of paleness, indisposition to exertion, excessive sleepiness, and feeling of coldness. Dyspeptic symptoms sometimes appear, and loss of appetite may alternate with ravenous hunger. Accompanying this there is often a disposition to eat innutritious articles, as coal, clay, wool, etc. Feeling of weight and oppression in the epigastrium and abdominal pains are frequent. In the advance of the affection shortness of breath appears, increased on exertion to violent dyspnoea. Emaciation becomes obvious in the later stage of the disease. In the worst cases the symptoms increase in severity, the patient becomes dropsical, is attacked with profuse diarrhoea and vomiting, and finally dies.

The severity of the affection is proportioned to the number of parasites present and the quantity of blood they consume and cause to be lost. Bad cases may end fatally in a few weeks, but generally the disease lasts for months, and where the patient is provided with abundance of good food it may continue for years.

The prognosis of the disease is rather unfavorable; if, however, the nature of the affection is ascertained before it has greatly exhausted the patient, and the parasites can be expelled, the result should be favorable.

We have thus far obtained but little information as to the best treatment for Anchylostomum. Calomel and turpentine have been recommended, and, as these are most powerful vermicides, we have reason to believe they would prove most effectual remedies.

In regard to the prophylaxis for Anchylostomum--and we may add in general for all parasites which gain entrance to man through drinking-water--all stagnant or standing waters should be filtered, so as to remove any source of infection, whether by eggs or free embryos of parasites or of larval forms existing within minute aquatic animals which serve as intermediate hosts to parasites. Standing waters, such as those of puddles, ditches, marshes, and ponds, more or less swarm with minute animals, all of which may be entirely removed by filtration. Even the water of cisterns and wells, if supplied from the free surface of the country, may not be free from minute animals, and especially eggs, and therefore requires filtration to be safe. Only spring and freely-running water of rivers and creeks and of lakes is commonly free from microscopic animals and their eggs, and therefore devoid of all danger in these respects.

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STRONGYLUS LONGEVAGINATUS; S. bronchialis.--This nematode has been only once satisfactorily observed. Many occurred in the lungs of a boy in Germany, but the real cause of his death was not stated. The female worm is about an inch long, the male about five-eighths of an inch.

Certain worms previously discovered in the bronchial glands of a case of phthisis, and described under the name of Hamularia lymphatica, are regarded by Cobbold as the same with the former; but the descriptions of the two render this improbable. Treutler's drawing of Hamularia, as copied by Leuckart, looks like an Ascaris upside down.

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{957} EUSTRONGYLUS GIGAS; Strongylus gigas; Palisade-worm; Kidney-worm.--This worm, recorded in the catalogue of human parasites, is doubtful as such. Pertaining to the same family as Anchylostomum, as the common name indicates its usual habitation is the kidney. It is the largest of the nematodes, and is a long, cylindrical red worm, slightly tapering, and blunt at the ends. The mouth is enclosed by six rounded labial papillæ. The caudal extremity of the male ends in an inverted cup-like pouch, from which the penal spiculum protrudes. The female commonly ranges from one to three feet in length and from a fourth to nearly half an inch in thickness. The male ranges from six inches to a foot in length and from one to three lines in thickness.

The mature parasite is common in many fish-eating mammals, from which it is inferred that fishes are the intermediate host for the juvenile condition of the worm. It is frequent in the wolf, dog, mink, weasel, raccoon, otter, and seal. It also occurs in the hog, and is reported to have occurred in the horse, ox, and man. Usually it is solitary, and occupies one of the kidneys coiled upon itself. Under its influence the kidney is atrophied and reduced to the condition of a capsule of connective tissue, often containing bony spicules. It feeds on blood and on the purulent matter resulting from the inflammation it produces. The worm is occasionally found in other positions, as the mesentery, the abdominal cavity, the intestine, liver, urinary bladder, and lungs, but perhaps in most of these cases has been derived from its usual habitation. In this country the writer has repeatedly observed the kidney-worm in the mink, the dog, and the wolf. In one instance in the former animal he found a female and a male associated together in one kidney, which was reduced to the condition of a fibrous capsule containing in its wall a large radiated plate of bone.