The Animal Parasites of Man

by Harold Benjamin Fantham; Max Braun; J. W. W. Stephens; Fred. V. Theobald

The diagnosis depends upon the proglottides being generally discharged in pieces in the stools, or eventually an examination for eggs. Larval infection (Cysticercus cellulosæ) occurs also in man through auto-infection or through food.

Cysticercus cellulosæ of the skin and subcutaneous tissue occurs very seldom singly; as a rule they are found in hundreds and thousands in the same individual. They occur in different parts of the body, especially on the flexor surfaces of the extremities (generally symmetrically), small globular swellings, the size of a pea or a hazel nut, smooth, of a tough cartilaginous consistence, fairly movable under the skin, in the muscles less so. They never degenerate or cause the surrounding skin to lose its colour. It is an interesting fact that in the case described by Posselt[711] nodules on the face, namely in the neighbourhood of the left cheek and behind the left ear, reformed. The following are, according to Posselt, characteristic for cutaneous tumours due to cysticerci: (1) the position in the subcutaneous connective tissue (and almost always simultaneously in the muscles); (2) the approximately equal size and regularly rounded oval form; (3) the peculiar density, almost reminding one of cartilage in its hardness and the sensation of tightly distended thick-walled bladders; (4) proportionately slight mobility; (5) with painlessness, absence of any cutaneous reaction (hyperæmia or swelling of the skin or pigmentation). The very gradual appearance generally of the tumours supports the diagnosis, and in addition to this evidence we may emphasize the preponderating liability of the upper part of the body to attack and the symmetrical arrangement of the nodules. Cutaneous and muscular cysticerci cause the most varied symptoms, sensory disturbances, abnormal sensations, depression and a feeling of weariness whenever the diseased parts are moved, weakness in the lower extremities, pains in the course of the sciatic nerve, in addition to those which simulate cramp in the calves, numbness in the hands, pains upon their being moved. In the case of a cysticercus situated in the elbow-joint, painful dragging sensation in the course of the ulnar nerve persisted. In other cases the arm was almost paralysed, or it could not be completely extended; stiffness and bending of the little finger were noticed. Cysticerci of the gluteal muscle cause trouble upon sitting and upon defæcation. Remittent unilateral headaches were present in the case of a cysticercus of the region of the right eyebrow; pains of a neuralgic character radiated from the diseased temporal region. The cysts may be inflamed and may suppurate; this especially happens in the case of solitary cutaneous and muscle cysticerci. The best treatment consists in puncture of the cysts with a Pravaz syringe and subsequent injection of a drop of 1 per cent. sublimate solution. Tincture of iodine has similarly been proposed (Wolff[712]). Frangenheim[713] recommends early extirpation (this, however, only in the case of solitary cysts). Pelagutti[714] believes that in his case diminution in the size of the cysts was obtained by the use of anthelminthic remedies continued over a long period combined with potassium iodide and calcium salts (internally). Cysticercus is very rarely found in the tongue; there the worms generally lie in front of the sulcus terminalis, corresponding to the middle of the tongue, according to Glas.[715] In the case recorded by Gaetano[716] (a boy, aged 10) there was a nodule on the left side of the tongue which grew very rapidly till it reached the size of a nut; it was embedded in the muscle and covered over by normal mucosa. Cysticerci are just as rare in the pleuræ, in the lungs, in the intestinal submucosa, in the submucosa of the small intestine, in the mesenteric glands, in the liver, pancreas, spleen and kidneys, in the mamma, in the heart, in the bones and in the great vessels (Huber[717]). Cysticercus of the eye deserves special mention; in rare cases the cysticercus has been met with in the subcutaneous cellular tissue of the eyelid, once in the muscle bundles of the musculus orbicularis. Subconjunctival cysts are found chiefly in youthful individuals. Their position is most varied, generally in the neighbourhood of the inner angle of the eye. Dilated vessels pass right over the cysts, which are generally movable, together with the base they rest upon, producing a spherical protrusion. The head of the worm can sometimes be seen shining through as a whitish speck. The only symptoms are those of a slight irritation of the connective tissue and some difficulty in closing the lid; larger cysts dislocate the globe. The diagnosis has the rapid growth of the cystic tumour to support it; there is the possibility of its being mistaken for a foreign body (Kaldrovils[718]). After division of the connective tissue capsule extraction is easily performed. It is most rare for the cysticercus to occur in the orbit. Suppuration of the cyst may have serious consequences for the eye. It is only exceptionally that the cysticerci gain access to the anterior chamber of the eye.

Subretinal cysticerci or those localized in the vitreous are more frequent. Upon examination with the ophthalmoscope there is seen in the vitreous a bluish bladder with a smooth surface. The head is seen as a white patch, and the circle of hooks and the suckers also come into view, also the frequent movements which the head and neck make in the vitreous. Operation generally yields good results; in rare instances the globe is atrophied and must be enucleated.

Formerly cysticerci in the brain were met with in fair frequency, but the number of such cases has generally decreased of late years in a remarkable way, in correspondence with the diminution of cysticerci, which is to be attributed to compulsory meat inspection. Whilst, for example, the post-mortem records of the Pathological Institute in Berlin before the year 1875 showed 20 per cent. cysticerci affecting the brain, this number declined later to 16·3 per cent., and of late years has fallen to 1 per cent. (Orth[719]). Nevertheless even now cysticercus still plays no inconsiderable part in the etiology of cerebral diseases. For example, in the clinic of de Amicis at Naples, among seven cases of cysticerci of the skin, they were found four times also in the brain (Sipari[720]). Cysticerci may occur in the dura mater, arachnoid, pia mater, choroid plexus, the surface of the cerebral hemisphere, the medullary substance, the ventricles, the aqueduct, the corpus striatum, corpora quadrigemina, the pineal gland, the pons, the cerebellum, the olfactory trigone, the bulb, the medulla oblongata, and the olive. They are most frequently found in the cortical substance and in the ventricles; the frequency of the latter situation may be explained by the flow of the fluid (Henneberg[721]). The severity of the symptoms is not always in proportion to the number of cysticerci. Cases have been known in which ten, twenty and forty cysticerci have been found (Hagen-Thorn[722]), and yet the clinical symptoms have been remarkably slight. On the other hand, solitary cysts may both run a course completely without symptoms and also cause the severest symptoms when located in specially important parts of the brain (crus, pons, central convolutions). In the case mentioned by Jacobson[723] the invasion of the brain by cysticerci was immense; the largest cyst was found in the cerebral cortex. The chief symptoms of cysticercus of the brain substance consist in the onset of cortical epilepsy, which sometimes runs a very pernicious course, frequently with psychical disturbances, whilst paralyses are absent. Perhaps, too, the localization of pain, spontaneous and on pressure, corresponding with the points observed on the cranium, is of importance. Cysticerci may also change their position in the brain; patients who had earlier suffered from epileptiform convulsions later showed intra-ocular cysticerci after the cerebral symptoms had completely disappeared. Treatment can only be surgical; v. Bergmann[724] operated in two cases with well-marked improvement. Parasites in the ventricles are especially dangerous, more especially so when free in the ventricles, and so capable of giving rise to the danger of sudden closure of the foramen of Majendie (Simmonds,[725] Versé[726]). Stern[727] states the symptoms of cysticercus in the fourth ventricle to be the following: general cerebral pressure symptoms (headache, vertigo, vomiting, somnolence, congested disc caused by internal hydrocephalus); in addition, there are symptoms which point to disease of the hind-brain—pain and stiffness in the neck, vertigo and cerebellar ataxy, violent and persistent vomiting, slowness of pulse; and lastly those rare but certain symptoms of a lesion of the bulb, such as diabetes, respiratory disturbances and paralysis of cerebral nerves, especially of the abducens. These are far less marked than the general symptoms of cerebral pressure. One characteristic is the remarkable alternation between severe general symptoms and periods of complete sense of well-being; in this way a functional nervous affection may be simulated (Jolasse[728]). Brun’s symptom (in the widest sense, sudden onset of violent cerebral symptoms upon change of head-posture) is a specially characteristic sign of free cysticercus in the fourth ventricle; the disease generally terminates with sudden death from cessation of the heart’s action. Defects in motor power, convulsions, implication of other nerves, are rare and unessential complications (Hartmann[729]). Carefully carried out, lumbar puncture may possess some diagnostic and therapeutic value. Treatment is purely symptomatic, or eventually Neisser’s ventricle puncture may be considered.

At the base of the brain the cysticerci, as a rule, assume that form which is designated as C. racemosus, and consists of rows of delicate grape-like bladders in groups, sometimes also markedly branched, but generally sterile, which develop in the meshes of the soft meninges and may envelop the nerves and vessels of the base of the brain. Such tumours bring about hydrocephalus and chronic leptomeningitis, which must be regarded as the causes of the clinical disturbances (cysticercus meningitis), attacks of loss of consciousness, dementia and apathy, dulness and confusion and headaches. In the case recorded by Meyer[730] symptoms which resembled paralysis agitans were noteworthy, and defects in speech in the case recorded by Durst[731] (C. racemosus in the region of the left Sylvian fossa). According to Markwald[732] C. racemosus of the fourth ventricle is said to represent a characteristic clinical picture: violent headaches, attacks of vertigo followed very soon by deep coma and death in a few days. Treatment in Cysticercus racemosus is ineffectual. In the diagnosis of cerebral cysticerci in general the recognition of multiple cysticerci in the skin and muscle and of the tapeworm is of importance. In cases of cerebral diseases in which cysticerci may be a possible cause, Remmert[733] recommends that the skin of the whole body should be palpated.

Cysticercus in the spinal cord and in the vertebral column is occasionally observed; as a rule, other organs, above all the brain and its membranes, are simultaneously affected. Here, too, the cysticercus occurs in two forms—sometimes the cysts are roundish or oval, solitary or multiple, and at other times Cysticercus racemosus occurs.

Tænia saginata.

Occurs in the small intestine of man. It is characteristic of the habit of life of this parasite that once it has become mature its proglottides are dropped off daily in increasing numbers because its growth is extraordinarily rapid. The joints are discharged generally spontaneously during the whole day without a stool. An extraordinarily unpleasant sensation is produced by the damp, cool joints slipping down into one’s lower garments and over one’s legs when walking; women especially, in whom the proglottides slip through their petticoats on to their legs, complain bitterly of this troublesome symptom. Another unpleasant symptom is superadded in the shape of the proglottides tickling the rectum, and this excites irritable people to the last degree. Different species of tapeworms are not mutually exclusive. B. latus and T. solium frequently occur side by side, so also T. solium and T. saginata—for instance, in a butcher’s assistant we once expelled twelve T. solium and one T. saginata at the same time. The greatest number of Tæniæ which have been observed at one time amounted to forty T. solium (Kleefeld[734]). Even though the cysticercus of T. saginata is not, as in the case of T. solium, particularly dangerous to man, a parasite, nevertheless, which requires so much nutrient material during its rapid growth, and thereby sets up manifold disturbances in the general condition of health, ought to be expelled as rapidly and thoroughly as possible.

Tapeworms are found not uncommonly with other intestinal parasites, such as Ascaris, Oxyuris, Trichocephalus or Ancylostoma. Prunac[735] described a case in which a woman passed a Tænia through the anus while she vomited a Fasciola hepatica.