Fig. 142.—Fasciola hepatica: egg from liver of sheep. o, operculum, e, segmenting ovum. The rest of the space is occupied by yolk cells, the granules in three only being shown. × 680. (After Thomas.)
[The first period is called the PERIOD OF IMMIGRATION. This occurs at the fall of the year and generally passes unperceived, as the young flukes do little harm to the liver. It varies from four to thirteen weeks. Gerlach has remarked upon cases of death from apoplexy at this period.
[The second period is the PERIOD OF ANÆMIA. This occurs in November and December. The sheep at first fatten rapidly, but later the mucous membranes become pale and of a yellowish hue, and the sheep become sluggish and cease to feed. The fæces are normal, but may contain fluke ova.
[The third period is the PERIOD OF WASTING. This corresponds with the beginning of January—about three months after the entry of the larvæ. Emaciation now becomes very marked, the skin and mucous membranes blanched, temperature variable and marked by an irregular curve; respiration laboured and quick; appetite regular; abortion frequently occurs in pregnant ewes; pressure on the back causes the animals to fall; local œdemas occur, the most perceptible in the submaxillary space, extending below the larynx and over the cheeks and parotids (called “bourse,” “boule” in France; “watery poke” or “cockered” in England). Death usually occurs at this period, but a fourth stage may occur.
[The fourth period is the PERIOD OF MIGRATION OF THE FLUKES. This is a period of convalescence and recovery, generally in May and June.—F. V. T.]
Oxen suffer less in general, but even in these animals “stray” hepatic flukes are occasionally found in the lungs, enclosed in thick-walled cysts.
Pathological Anatomy.—The bile-ducts are conspicuous on the surface of the liver. They are thickened and much dilated and in parts saccular, and considerable atrophy of the liver cells accompanies the condition. Histologically there is immense proliferation of the epithelium of the bile-ducts leading to “adenomata.”
Fig. 143.—Limnæus truncatulus, Müll., the intermediate host of Fasciola hepatica. a., natural size; b., magnified. (From Leuckart.)
The LIFE-HISTORY of the liver fluke was discovered by R. Leuckart and P. Thomas. According to these investigators the elongated miracidium (fig. 131, a) ciliated all over develops from the eggs a few weeks after the latter (fig. 142) have reached the water, and after it has become free the embryo penetrates and becomes a sporocyst (fig. 131, b) in a water-snail (Limnæus truncatulus, Müll. = L. minutus, Drap.) that is common in fresh water, and can live in the smallest collection of water as well as in fields that have been flooded. The sporocyst first of all produces rediæ, which remain in the same host (and under certain circumstances, e.g. in summer, these develop a second generation of rediæ), and these finally form cercariæ (fig. 134). The latter become encysted on blades of grass and are taken up by the respective hosts with their food; this takes place towards the end of summer, while the sheep feeding on the pasture land in the spring spread the eggs of the fluke, and sometimes the fluke itself, by passing them with their fæces.
In districts where Limnæus truncatulus is absent, analogous species act as the intermediary hosts, of which one example according to Lutz is Limnæus oahuensis in the Sandwich Islands.
[The host in Europe is Limnæus truncatulus. This snail extends from Siberia to Sicily and Algeria, and according to Captain Hutton is a native of Afghanistan. It also occurs in Thibet, Amoor, Morocco, Tunis, Canary Islands and the Faroe Islands. It deposits its eggs or spawn upon the mud around ponds, ditches and streams. The eggs are laid in batches of thirty to a hundred, each snail laying as many as 1,500 eggs; they are united into strips of a gelatinous substance. In about two weeks young snails appear. It is amphibious, being more frequently met with out of the water than in it. It occurs in elevated spots as well as in low-lying districts. Moquin-Tandon found it at 4,000 feet in the Pyrenees. In the allied species, L. peregra, the fluke will develop up to a certain stage, but never completes all its varied phases.
[In South America the host is probably Limnæus viator, Orb., and in North America Limnæus humilis, Say.—F. V. T.]
In human beings as well as in some of the mammals quoted above, the liver fluke is only a casual parasite, and hitherto only twenty-eight cases have been observed in man; the infection was mostly a mild one and there were no symptoms, or only very trifling ones; a few isolated cases were only discovered post mortem. Occasionally, however, even when the infection was inconsiderable, severe symptoms were set up, which in isolated cases led to death. The symptoms (enlargement and painfulness of the liver, icterus) merely pointed to a disease of the liver.
Diagnosis can only be established by finding eggs in the fæces. Care should be taken not to confuse them with those of Dibothriocephalus latus.
Halzoun.
Fig. 144.—Young Fasciola hepatica, soon after entry into the liver. The intestinal cæca have lateral diverticula. Magnified. (From Leuckart.)
In North Lebanon, the liver fluke is, according to A. Khouri, a frequent parasite of man, not in the liver, however, but in the pharynx. The occurrence in this unusual site is effected by the eating of raw infected livers, especially those of goats (Capra hircus). The flukes thus taken in do not all reach the stomach, where they would be soon killed, but some of them attach themselves to the pharyngeal mucosa and to the adjoining parts, and there cause inflammation and swelling, which lead to dyspnœa, dysphagia, dysphonia and congestion of the head, sometimes even to still more severe symptoms, and even death. The affection termed “Halzoun” lasts some hours or several days, and after vomiting recovery sets in. In other cases man becomes infected in the usual way by ingesting cysts attached to grass or the underside of leaves of plants (e.g., Rumex sp.), where they are overlooked from their scanty size (0·2 to 0·3 mm.).
As the liver fluke feeds on blood it is possible that it also reaches, particularly when young, the circulatory system, and cases have been known in which it has been carried by the blood into organs far from its original situation. Such cases also have been repeatedly observed in men. Probably the parasite described by Treutler, 1793, as Hexathyridium venarum, which protruded from the ruptured anterior tibial vein of a man, was a young liver fluke. A few adult specimens were found by Duval in the portal and other veins post mortem at Rennes (1842) in a man, aged 49, and a similar statement is reported by Vital from Constantine (1874). Giesker, in 1850, found two hepatic flukes in a swelling on the sole of the foot of a woman. Penn Harris states that he observed six specimens in Liverpool in a spontaneously ruptured abscess of the occiput of a two months old infant. Another case which, like the previous one, is reported by Lankester,271 relates to a sailor who suffered from an abscess behind the ear, and from which a liver fluke was expelled. Finally, Dionis de Carrières reports the case of a man, aged 35, in whose right hypochondriac region a tumour the size of a pigeon’s egg had formed, and from which a young liver fluke was extracted.
From such records it is not impossible that Distomum oculi humani, Ammon, 1833, as well as Monostomum lentis, v. Nordm., 1832, may have been very young hepatic flukes that had strayed. Ammon found four specimens (length 0·5 to 1 mm.) of his species (named Distomum ophthalmobium by Diesing in 1850) between the opaque lens and the capsule of a five months old child in Dresden, and von Nordmann discovered his Monostomum lentis to the number of eight specimens (only 0·3 mm. in length) in the opaque lens of an old woman. Minute white bodies which Greef found in the cortex of the lens of a fisherman, aged 55, removed on account of cataract, were with some reserve regarded as Trematode larvæ. The fact that Ammon found that the intestinal cæca of the worm discovered by him had no lateral branches does not negative the above opinion, as in the liver fluke the intestinal cæca are originally unbranched, and according to Lutz they only develop lateral ramifications later, between the twelfth and twenty-second day of infection (fig. 144).
Fasciola gigantica, Cobbold, 1856.
Syn.: Distomum giganteum, Diesing, 1858; Fasciola gigantea, Cobbold, 1858; Cladocœlium giganteum, Stoss., 1892; Fasciola hepatica var. angusta, Raill., 1895; Fasciola hepatica var. ægyptiaca, Looss, 1896.
This species is closely allied to Fasciola hepatica, but is distinguished by its elongated body, short cephalic cone, almost parallel sides, larger ventral sucker, which is also closer to the oral sucker, and by its larger eggs. Length up to 75 mm., width up to 12 mm. Oral sucker 1 to 1·2 mm., ventral sucker up to 1·7 mm. in diameter. Eggs 150 µ to 190 µ long by 75 µ to 90 µ broad.
Habitat.—Bile-ducts of Camelopardalis giraffa, Bos taurus, Bos indicus, Bos bubalis, Ovis aries and Capra hircus.
Distribution.—Africa.
This species has once been observed in man by Gouvea, in Rio de Janeiro, in a French naval officer who became ill with fever, cough and slight blood-spitting. The lungs were normal except for a sharply circumscribed spot at the base of the left lung. Twenty days later during a fit of coughing the patient spat up a fluke 25 mm. long, characterized by its slender aspect and by the size of its ventral sucker, and its close proximity to the oral sucker. Considering the fact that Gouvea’s patient had spent many weeks in July of the same year in Dakar (Senegambia), where according to Railliet Fasciola gigantica is common in slaughtered animals, and considering also the characters of the fluke, Railliet rightly assumes that one had to do with the African giant fluke and that the patient had infected himself in Dakar.
Sub-family. Fasciolopsinæ, Odhner, 1910.
Genus. Fasciolopsis, Looss, 1898.
Ventral sucker large, and elongated posteriorly into a sac. Cirrus pouch long and cylindrical, its greatest length being occupied by the sinuous tubular seminal vesicle, on which exists a peculiar cæcal appendage. Laurer’s canal present.
Fasciolopsis buski, Lank., 1857.
Syn.: Distomum buski, Lank., 1857; Dist. crassum, Cobbold, 1860, nec v. Sieb., 1836.
Fig. 146.—Fasciolopsis buski, Lank. V.s., ventral sucker; C.p., cirrus pouch; I., intestinal fork; S.v., vitellaria; T., testes; O., ovary; Ms., sucker; Shg., shell gland; Ut., uterus. Magnified. (After Odhner.)
The length of the body varies; it may measure 24 to 37 or even attain 70 mm.; the breadth is from 5·5 to 12 to 14 mm. In the pig the fresh parasites measure, smallest, 12 to 8 mm.; largest, 35 to 16 mm. (Mathis and Léger). Skin without spines, but according to Heanly always present in man and pig specimens. The oral sucker measures 0·5 mm. in diameter; the ventral sucker is three to four times as large; the pharynx is globular, 0·7 mm. in diameter; the prepharynx is provided with a sphincter; the intestinal cæca extend to the posterior border with two characteristic curves, one at the anterior border of the anterior testis, the other between the two testes. The genital pore is at the anterior border of the ventral sucker; the cylindrical cirrus pouch extends from behind the ventral sucker to half-way to the shell gland. The seminal vesicle extends forwards within the cirrus pouch as a convoluted tube. From its anterior portion is given off the cæcal appendage, which has itself short lateral diverticula. It runs backwards, ending blindly about 0·5 mm. from the posterior end of the cirrus sac. The seminal vesicle is continued as the pars prostatica (?) 0·5 mm. long, and this by the very short ejaculatory duct (13 µ), and finally by the fairly long cirrus, which is beset with very fine spines except at either extremity. The ovary and shell gland are situated at about the middle of the body with the testes behind them, and the uterus in front. The vitellaria extend from the ventral sucker to the posterior border. The eggs measure 120 µ to 130 µ in length and 77 µ to 80 µ in breadth, and resemble those of Echinochasma sp. in dogs. The larval stages are said to occur in shrimps.
Habitat.—Intestine of pig and man.
Distribution.—In man: India, Siam, China, Assam, Sumatra. It is common in Cochin China (16 out of 133 Annamites, Noc.), in Tonkin very rare. Dr. J. Bell has sent me [J. W. W. S.] human specimens from Hong Kong. In pigs: very common in South China (Heanly). Common in pigs in Hong Kong. Sixteen out of 248 pigs (i.e., 6 per cent.) infected in Hanoi.
Fasciolopsis rathouisi, Ward, 1903.
Syn.: Distomum rathouisi, Poirier, 1887.
Fig. 147.—Fasciolopsis rathouisi, Poir.: the mouth at the top, and under it the genital pore and ventral sucker, behind which again is the uterus. The vitellaria are at the sides, and posteriorly in the central field the ramified testes; the ovary is in front of the right testis. (After Claus.)
Fifteen to 19 mm. long by 8·5 to 10·5 mm. broad by about 3 mm. thick. Skin with spines (Leiper). Bluntly oval or elliptical with short cephalic cone which is absent in Fasciolopsis buski. Oral sucker subterminal, 0·25 to 0·29 mm. broad by 0·2 mm. in antero-posterior diameter. Distant from ventral sucker by about twice its diameter. Ventral sucker 1·32 to 1·38 mm. broad by 0·68 to 0·7 mm. in antero-posterior diameter. Œsophagus extremely short. Cirrus sac not conspicuous and straight as in Fasciolopsis buski, but is convoluted. Testes one behind the other (according to Poirier they lie beside one another), more compactly branched, broader and denser than in Fasciolopsis buski. Ovary on right side, small, coarsely branched. Uterus in broad, closely grouped coils, packed with ova anterior to ovary. Vitellarian acini more numerous and somewhat differently distributed. Eggs 150 µ by 80 µ, thin shelled. [H. B. Ward, who has examined this species, and from whose account the above is mainly taken, considers that it is a good species, although the differences between it and Fasciolopsis buski are slight, while Odhner, who examined the original species, is of the opposite opinion.—J. W. W. S.] The parasite appears to cause diarrhœa, wasting and occasionally jaundice.
Habitat.—Intestine of man.
Distribution.—China, common in some parts (Goddard).
Fasciolopsis goddardi, Ward, 1910.
Twenty-one to 22 mm. long, 9 mm. broad. Skin with spines (Leiper). Uterus very closely coiled, most striking character is the large size of the vitelline acini. Imperfectly known.
Distribution.—China (Shanghai).
Fasciolopsis fülleborni, Rodenwaldt, 1909.
The fully extended fluke is tongue-shaped, 50 by 14 mm.; two contracted specimens measured 40 by 15 mm. and 30 by 16 mm. respectively. Skin without spines, with according to Leiper cephalic cone not clearly defined. Oral sucker circular, 0·75 mm. in diameter, slightly larger than that of Fasciolopsis buski. Ventral sucker 2·6 mm. in diameter (that of Fasciolopsis buski 1·6 to 2 mm.). Length 2·9 mm. (as in Fasciolopsis rathouisi), the excess of length over breadth being due to the posterior elongated sac-like prolongation of the sucker. Prepharyngeal sphincter present. Pharynx 0·7 mm. in diameter. Œsophagus practically absent. Gut cæca similar to those of Fasciolopsis buski.
Testes—regularly branched, separated by an incurving of the cæca, the anterior occupying a smaller area than the posterior.
Ovary—very small, as in Fasciolopsis buski, on the right side.
Shell Gland—almond-shaped, 2·3 by 1·2 mm. In Fasciolopsis buski it is round and smaller, 1 to 1·5 mm. in diameter.
Vitellaria—similar in distribution to those of Fasciolopsis buski, but the acini are strikingly small.
Cirrus Sac—is the most characteristic feature of this species. It is a powerfully built, convoluted sac standing out clearly on the body. It is not a uniform, straight cylinder 0·25 to 0·33 mm. in diameter, as in Fasciolopsis buski, but even in fully extended flukes is typically convoluted. It is 1 mm. thick in the middle, but in other parts varies much from this. The posterior end of the cirrus sac is at two-thirds or more of the distance from ventral sucker to shell gland. In the case of Fasciolopsis buski the posterior end of the sac only extends half-way.
Seminal Vesicle—has a peculiar convoluted, saccular and angular course, but the cæcal appendage characteristic of the genus appears to be absent!
Excretory System.—The main stem gives off very regular transverse branches which are well seen posteriorly.
Eggs.—100 µ by 73 µ. Thin shelled.
Habitat.—Intestine. Mahommedan from Calcutta.
[It is evident that a re-examination of fresh material is required before the validity of all these species can be accepted.—J. W. W. S.]
Family. Troglotremidæ, Odhner, 1914.
Genus. Paragonimus, Braun, 1899.
Body egg-shaped or somewhat elongated, generally more broadly rounded in front than behind. Covered all over with spear-shaped spines arranged in groups. Gut cæca winding with dilatations or constrictions in parts. Ventral sucker in or in front of the middle of the body. Excretory bladder cylindrical, very long and broad, reaching in front to the bifurcation of the gut. The lateral excretory canals join the bladder only a little in front of the excretory pore. Genital pore median just behind the ventral sucker. Genital sinus duct-like. Cirrus sac absent. Male terminal organs very small. Ejaculatory duct present. Testes and ovary deeply lobed, the testes in or just behind the middle, the ovary somewhat laterally placed just behind the ventral sucker. Uterus forms a coil behind the ventral sucker. Eggs rather large, thin shelled, the ovarian cell still unsegmented on deposition. Receptaculum seminis, small.
Parasitic in the lungs of mammals, enclosed in cyst-like cavities, generally in pairs.
Type Species.—P. westermanii in the tiger.
Paragonimus ringeri, Cobb., 1880.
Syn.: Distoma ringeri, Cobb., 1880; Distoma pulmonale, Baelz, 1883; Distoma pulmonis, Suga, 1883.
Fig. 149.—Paragonimus ringeri, Cobb.: to the right, dorsal aspect; to the left, ventral aspect. Natural size. (After Katsurada.)
The body is of a faint reddish-brown colour and plump oval shape. The ventral surface a little flattened; 7·5 to 12 mm. in length, 4 to 6 mm. in breadth, and 3·5 to 5 mm. thick (in man). The oral sucker (0·75 mm.) is subterminal; the ventral sucker (0·8 mm.) somewhat in front of the middle of the body. Pharynx spherical, 0·3 mm. in diameter, or 0·4 by 0·3 mm.; œsophagus, 0·02 mm.; intestinal cæca convoluted, asymmetrical, the first part having the same structure as the œsophagus. The cuticle is covered with spines in groups; the excretory pore opens at the posterior end rather on the ventral surface, the excretory ducts open into the elongated bladder at the hind end near the pore. Genital pore behind the ventral sucker and median. Genital sinus 0·2 mm. long with thick wall, ejaculatory duct 0·13 mm., pars prostatica 0·2 mm., seminal vesicle duct-like of irregular outline. Behind the sucker the ovary on the left, and the closely packed uterine coil on the right (though amphitypy of these two organs is common); the two irregularly lobed testes lie side by side posteriorly. Vitellaria extensive, leaving only a median dorsal and ventral space free. Seminal receptacle probably absent; Laurer’s canal present. The eggs are oval, brownish-yellow, fairly thin shelled, and measure on an average 81·2 µ by 49·2 µ.
Fig. 150.—Paragonimus ringeri, Cobb.: diagram of the internal organs. a, œsophagus; b, vitellaria (a portion only shown); c, common genital duct; d, shell gland with oviduct, Laurer’s canal and vitelline duct; e, ovary; f, vitelline receptacle; g, excretory pore; h, oral sucker; i, pharynx; k, gut; l, ventral sucker; m, uterine coils; n, vitellarian ducts; o, vas efferens; p, testis. (After Kubo.)
Fig. 150a.—Paragonimus westermanii, Kerb.: seen from the ventral surface. Mouth, pharynx, intestinal cæca, at the sides of which the vitellaria are observed. The genital pore is behind the ventral sucker, and next to it, on the left, the ovary; on the right, the uterus; the two testes posteriorly; the excretory vessel in the middle, 10/1. (After Leuckart.)
The following species are also known:—P. westermanii, Kerb., 1878, in the tiger, and P. kellicotti, Ward, 1908, in the pig, dog, and cat (N. America). Ward and Hirsch give the following differences between the spines of the three forms:—
P. ringeri. | P. westermanii. | P. kellicotti. | |
| Shape | Chisel-shaped, mod- erately heavy. | Lancet-shaped, very slender. | Chisel-shaped, heavy. |
| Distribution | Circular rows, in groups. | Circular rows, in groups. | Circular rows, singly. |
Two other species, P. rudis, Diesing, 1850, in a Brazilian otter (Lutra brasiliensis) and P. compactus, Cobbold, 1859, in the Indian ichneumon, are but little known.
Habitat.—Lungs, pleuræ, and especially the bronchi of man and dog. The alleged occurrence (of eggs) in other organs may be due to confusion with those of Schistosoma japonicum.
Fig. 151.—Egg of Paragonimus ringeri, Cobb., from the sputum. Showing the ovarian cell and vitelline cells and granules. 1,000/1. (After Katsurada.)
Distribution.—China, Korea, and especially in Japan, where, according to Katsurada, there are no districts that are entirely free from pulmonary flukes. The mountainous provinces of Okayama, Kumamoto, Nagano and Tokushima are the principal centres.
Pathology.—The number present in the lung varies from two to twenty, about. Usually one cyst contains one worm, but in the dog each cyst contains two. The cysts admit the tip of the finger, and have a fibrous wall 1 mm. thick. They originate partly from dilatation of bronchi and bronchioles. Others arise from the inflammatory reaction of lung tissue into which the worms have wandered. The worms and their eggs cause bronchitis and peribronchitis, catarrhal, hæmorrhagic, or purulent, and areas of consolidation. Areas containing eggs in their centre resembling tubercle nodules are not uncommon, and extensive cirrhosis of the lung may be found. As a result of these changes, emphysema and bronchiectasis also occur.
As to the development, only the following details are known: that the eggs, which before segmentation of the ovum reach the open in the sputum and through being swallowed also in the fæces, develop in water into a miracidium ciliated all over, which hatches and swims about freely. According to Manson this takes place in four to six weeks.
Sub-family. Opisthorchiinæ, Looss, 1899.
Genus. Opisthorchis, R. Blanch., 1845.
Opisthorchiinæ with lobed testes. Laurer’s canal present. Parasitic in the bile-ducts of mammals and birds.
Opisthorchis felineus, Riv., 1885.
Syn.: Distoma conus, Gurlt, 1831 (nec Creplin, 1825); Distoma lanceolatum, v. Sieb., 1836, v. Tright, 1889 (nec Mehlis, 1825 = Fasciolo lanceolata, Rud., 1803); Distoma sibiricum, Winogr., 1892; Distoma tenuicolle, Mühl., 1896.
This parasite is yellowish-red in the fresh condition, and almost transparent. The body is flat, with a conical neck at the level of the ventral sucker marked by a shallow constriction; this, however, is only noticeable in fresh and somewhat contracted specimens. Posteriorly to the ventral sucker the lateral borders run fairly parallel; the posterior end is either pointed or rounded off. The length and breadth vary according to the contraction, being usually 8 to 11 mm. by 1·5 to 2 mm. The suckers are about one-fifth to one-sixth of the length of the body distant from each other, and of about equal size (0·23 to 0·25 mm.). The œsophagus is hardly any longer than the pharynx, which lies close behind the oral sucker; the intestinal cæca reach almost to the posterior border and are often filled with blood. The excretory pore is at the posterior extremity, and the excretory bladder forks in front of the anterior testis. The testes in the posterior fourth of the body lie obliquely one behind the other; the anterior one has four lobes, the posterior one five lobes; the ovary is in the median line transversely, simple or slightly lobed; behind it lies the large pear- or retort-shaped receptaculum seminis and Laurer’s canal. The uterus is in the median field. The vitellaria occupy the fairly broad lateral areas, in about the central third of the body, beginning behind the ventral sucker and terminating at about the level of the ovary; the acini are small and arranged in groups of seven to eight, separated by interstices. The genital pore is close in front of the ventral sucker. The eggs are oval with sharply defined operculum at the pointed pole, 30 µ, by 11 µ.
Fig. 153.—Opisthorchis felineus: from the cat. m., mouth; p.b., pharynx; i., gut; g.p., genital pore; ac., ventral sucker; ut., uterus; v.g., vitellarium; ov., ovary; s.g., shell gland; r.s., receptaculum seminis; t. testes; ex. p., excretory pore. (After Stiles and Hassall.)
This species, which is frequently confused with others, inhabits the gall-bladder and bile-ducts of the domestic cat especially; but is also found in the dog, in the fox, and in the glutton (Gulo borealis). It has been observed in France, Holland, North Germany (being particularly frequent in East Prussia), in Russia, Scandinavia, Siberia, Japan, Tonkin, Hungary, and Italy. The North American form (from cats and Canis latrans) is a distinct species (Opisthorchis pseudofelineus).
In man this species was first found by Winogradoff in Tomsk (nine cases), then by Kholodkowsky in a peasant from the neighbourhood of Petrograd who had travelled a great deal in Siberia, and finally by Askanazy in five persons who were natives of the East Prussian district of Heydekrug. In Tomsk, Opisthorchis felineus is the most frequent parasite of man that comes under observation at post mortem (6·45 per cent.), whereas Tænia saginata has only been found in 3·2 per cent., Echinococcus in 2·4 per cent., Ascaris lumbricoides in 1·6 per cent., and Oxyuris vermicularis in 0·8 per cent. of the autopsies. In the district of Heydekrug, however, the species in question is also frequent, as in a few years five cases came to our knowledge (of which three were diagnosed by the discovery of the eggs in the fæces).
In none of Winogradoff’s nine cases had the death of the patient been caused direct by the parasites, yet more or less extensive changes in the liver were found in all of them; such as dilatation of the bile-ducts with inflammation and thickening of their walls, and foci of inflammation or atrophy in the liver substance; icterus was present five times and atrophy of the liver an equal number of times; ascites was observed three times, and in two cases, probably of recent date, the organ was enlarged. The number of parasites found fluctuated between a few and several hundreds.
In two of Askanazy’s cases, which he examined more closely, carcinoma which had developed at the places most invaded by flukes was found at the post-mortem, so that perhaps there may be grounds for the connection which the author seeks to establish between cancer of the liver and the changes induced by the parasites; these changes consist of numerous and even ramified proliferations of the epithelium of the biliary duct into the connective tissue, which is likewise proliferated. The number of worms found in one case amounted to over 100; in a second case, in which the parasites had also invaded the pancreatic duct, their number was even larger.
Fig. 154.—Opisthorchis pseudofelineus: from the bile-duct of the cat (Iowa), m., oral sucker; p.b., pharyngeal bulb; es., œsophagus; i., intestine; va., vagina; g.p.m., male orifice; ac., ventral sucker; ut., uterus; v.g. vitellarium; s.g., shell gland; v.dt., vitelline duct; ov., ovary; r.s., receptaculum seminis; L.c., Laurer’s canal; t., testis; ex.c., excretory bladder; ex.p., excretory pore. (After Stiles.)
Winogradoff as well as Askanazy found isolated flukes in the intestine also.
Unfortunately, nothing much is known of the history of the development of Opisthorchis felineus; we only know that when deposited the eggs already contain a ciliated miracidium, which, however, according to my experience, does not hatch out in water, but only after the entry of the eggs into the intestine of young Limnæus stagnalis; no further development, however, occurs. Winogradoff states that he has seen the miracidia hatch after the eggs had been kept in water for a month at 37° C.; and has even observed free miracidia in the bile of man and of a dog respectively. Although the whole post-embryonal development of the cat fluke remains yet to be investigated, Askanazy by a series of experiments on cats and dogs has discovered the mode of infection. The intermediate hosts are fish, and mainly the ide, in this country called Tapar (Idus melanotus, H. and Kr.), and of subsidiary importance the roach (Leuciscus rutilus). Both species of fish as well as others are readily eaten raw by man on the Courland lagoon (Baltic). It is, moreover, significant that those persons whom Askanazy found infected with the cat fluke were also infected with Dibothriocephalus latus, the intermediate host of which is also fish (Lota sp., Esox sp., Perca sp.).
In one of his nine cases Winogradoff also saw a small fluke covered all over with spines, which he conjectured to be the young stage of Opisthorchis felineus; as, however, according to my experience, this species, even in smaller specimens, is always without spines, the above hypothesis cannot be accepted. It is much more probable that one of the other species that also invade the liver of cats may accidentally be introduced into man; we know, in fact, that Metorchis albidus, Braun, and Metorchis truncatus, Rud., are both covered with spines. As, however, the spines of the first-named species are rather apt to fall off, and also as it possesses a different shape (spatula-shaped), it may be assumed that probably Winogradoff had found Metorchis truncatus, Rud., 1819, in his patient.
Genus. Paropisthorchis, Stephens, 1912.
Structure as in Opisthorchis, except that the ventral sucker and genital pore occur on the apex of a process or pedicle projecting from the anterior portion of the body. This process is about 12 mm. long, and is retractile.
Paropisthorchis caninus, Barker, 1912.
Syn.: Distoma conjunctum, Lewis and Cunningham, 1872; Opisthorchis noverca, M. Braun, 1903 (pro parte); Opisthorchis caninus, Barker, 1912 (?).
Length varies from 2·75 to 5·75 mm. in preserved specimens, average 3·6 to 5·2 mm. Body uniformly spinose, though as a rule spines are not present on the pedicle. Body slightly concavo-convex, the concavity being ventral. Oral sucker 0·28 mm. Pharynx 0·224 by 0·184 mm. Œsophagus 0·04 mm. Ventral sucker 0·176 mm. in diameter. Pedicle about 12 mm. long, may be completely retracted.
Fig. 155.—Paropisthorchis caninus: from the bile-ducts of the pariah dog, India. Acet. v., ventral sucker; Ut., uterus; V. ex. lat., longitudinal excretory duct; V. sem., seminal vesicle; Sem. rec., seminal receptacle; Ov., ovary; V. ex., excretory bladder; Test. l., left testis; Test. r., right testis; P. ex., excretory pore. × 40. (After Stephens.)
Genital Pore—opens on the apex of the pedicle in front of the ventral sucker. Its exact position varies with the state of contraction of the parts. In certain cases it actually opens within the cuticular border of the sucker, in other cases it opens externally to the sucker and anterior to it. The opening is covered with scales. The vas deferens and uterus run alongside one another until they merge near the apex of the pedicle into a common sinus.
Vitellaria—consist of eight acini on each side, extending from slightly behind the base of the pedicle to the anterior border of the ovary, or as far back as a line separating the posterior border of the ovary from the anterior border of the anterior testis.
Testes.—Anterior testis 0·496 by 0·44 mm.; posterior testis 0·52 by 0·48 mm., usually ovoid, though both may be regularly lobed. The anterior testis is usually on the left side.
Ovary—multilobular, the lobes 6 to 8 being irregular in size and shape.
Shell Gland—extensive and diffuse, occupying an area which approximately corresponds with the loop of the transverse vitelline ducts.
Seminal Receptacle—globular, to the right of and dorsal to the posterior lobe of the ovary.
Laurer’s Canal—generally runs from the end of the receptacle with a single curve medially and backwards.
Uterine Coils—form loosely packed transverse coils terminating slightly in front of the level of the first vitelline acini. From here the uterus passes forwards into the pedicle to the left and ventral to the seminal vesicle.
Seminal Vesicle—commences about the level of the first vitelline acini. The coils displace the uterus ventrally and to the left. In the pedicle the vesicle diminishes in extent and lies in its dorsal (anterior) side.
Habitat.—Liver of pariah dogs, India. In North-Western Provinces about 40 per cent. are infected. This fluke appears to be different from Amphimerus (Opisthorchis) noverca in man, as the latter has not the pedicle on the summit of which lie the sucker and common genital pore.
Fig. 156.—Amphimerus noverca, Braun. o.s., oral sucker; p.b., pharynx; ac., ventral sucker; ut., uterus; v.g., vitellarium; ov., ovary; v.d., vas efferens; ex.c., excretory canal; t., testis. (After McConnell.)
Genus. Amphimerus, Barker, 1912 (?).
Structure as in Opisthorchis, except that the vitellaria are separated into two portions, an ant-ovarial and a post-ovarial.
Amphimerus noverca, Barker, 1912 (?).
Syn.: Distomum conjunctum, McConnell, 1876 (nec Cobbold, 1859); Opisthorchis noverca, M. Braun, 1903 pro parte.
At the autopsy of two Mahommedans who died in Calcutta, McConnell found a large number of Distomata in the thickened and dilated bile-ducts. The worms were lancet-shaped, covered with spines, and measured 9·5 to 12·7 mm. in length and 2·5 mm. in breadth. The two suckers lie very close to one another, the anterior one being larger than the ventral; the genital pore opens immediately in front of the ventral sucker; pharynx spherical; intestinal cæca extending far back. At the commencement of the posterior third of the body the two testes, somewhat apart, the anterior one roundish, the posterior one distinctly lobed. The transverse and slightly lobed ovary in front of the bifurcation of the Y-shaped excretory bladder, whence the uterus, in convolutions barely spreading beyond the central field, extends to the pore; the vitellaria in the lateral areas commence behind the ventral sucker and extend to the testes. Cirrus pouch absent. Eggs oval, 34 µ by 21 µ.
Genus. Clonorchis, Looss, 1907.
Structure as in Opisthorchis, distinguished, however, by the branched testes situated one behind the other, the branches of which ventrally encroach upon the gut forks; dorsal to the testes the S-shaped excretory bladder, the main branches of which, arising at the level of the bifurcation of the gut, open into the bladder below its anterior end. Parasitic in the bile-ducts of mammals and man.
Fig. 157.—Metorchis conjunctus,272 (Syn.: Distomum conjunctum, Cobb., nec Lew. and Cunn., nec McConn.): from Canis fulvus. Vs., ventral sucker; I., intestine; Vsc. vitellaria; Ex., excretory bladder; T., testes; O., ovary; Ms., oral sucker; Ph., pharynx; Ut., uterus. (After Cobbold.)
Clonorchis sinensis, Cobbold, 1875.
Syn.: Distoma sinense, Cobbold, 1875; Distoma spathulatum, R. Leuckart, 1876 (nec Rudolphi, 1819); Distoma hepatis innocuum, Baelz, 1883.
In shape resembles Opisthorchis felineus, 13 to 19 mm. long, 3 to 4 mm. broad, at the beginning of sexual maturity 12 to 13 mm. long, 2·5 to 3 mm. broad. Oral sticker 0·58 to 0·62 mm., ventral sucker 0·45 to 0·49 mm. in transverse diameter. In the parenchyma numerous yellowish or brownish granules, especially behind the oral sucker and at the posterior end. Testicular branches very long, in the anterior testis often four, in the posterior testis five branches. Ovary generally with three large lobes and a smaller lobe. Vitellaria not always symmetrical, generally extending laterally from the ventral sucker to the ovary, interrupted in parts.
Eggs 26 µ to 30 µ by 15 µ to 17 µ. Average 29 µ by 16 µ.