The Animal Parasites of Man

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

Ascaris lumbricoides is one of the most frequent parasites that occur in man, both in adults as well as in children; as a rule, indeed, it most frequently infects children of medium age. The normal situation is the small intestine; this, however, is frequently left, and the Ascarides travel into the stomach, œsophagus, pharynx, bronchi, the nasal cavities and still other regions. It is a peculiarity of the Ascarides that they are prone to glide into narrow canals; for example, Clason[889] records that in the case of an idiot whose custom it was to swallow glass beads, the Ascarides showed a predilection for sticking in the beads and were passed in the fæces. The disturbances which Ascarides occasion in the intestine itself vary; isolated species do not give rise to any symptoms at all, whereas a large number may eventually give rise to severe local symptoms, or those of a toxic or reflex nature which have been discussed in the General Section.

Among the local symptoms are the following: loss of appetite, excessive appetite, perverted sense of taste, fœtid breath, sensitiveness to pressure over the abdomen, colicky pains and irregularity of the bowels. The appearance and state of health suffer; the patients, children in especial frequency, become remarkably pale; their complexions undergo rapid change, and rings of grey or bluish-brown are seen about the eyes. Children may become so reduced by this rare condition, enteritis verminosa, due to Ascarides in large numbers, that suspicion of the existence of intestinal tuberculosis arises. Emaciation to a skeleton, excessive meteorism, and evacuations of thin gruel-like stools, sometimes blood-stained, are observed in these cases. Even in the case of adults, chronic uncontrollable vomiting with severe inanition due to the Ascarides has been observed. When the Ascarides escape spontaneously per anum, they frequently cause an exceedingly troublesome irritation in the anal region (pruritus ani).

The most disagreeable symptoms and those most dangerous to life arise from the migrations of Ascarides when they invade the bile-ducts; no inconsiderable number of cases of this kind are recorded in the literature (summarized, up to the year 1901, in Sick’s[890] Dissertation). Penetration post mortem (or shortly before death) of the worms into the bile-ducts cannot be considered as a rarity; the laxity of the muscular orifices easily allows of this invasion also in other directions on the part of the parasite in its escape from the body of its dead host. The occurrence of the worm in the biliary passages in the living is to be regarded as still less frequent, but nevertheless often enough according to the records in literature. Sick[891] was able to collect as many as sixty-one such cases, to which he added two further fresh cases from the Tübingen clinic, that is, from the material provided by his father. In the year 1891 Borger[892] collected fifty-nine cases relating to the invasion by Ascaridæ of the bile-ducts and passages, and Dauernheim’s[893] Dissertation treats of this question as well. A further case of Ascaris in the ductus choledochus (choledochotomy) is recorded by Neugebauer.[894] In the case of Schupper[895] (woman, aged 52), all the biliary passages were distended and filled with fourteen living Ascaridæ (perhaps as they were living they had not led to a septic infection of the biliary passages); in the case communicated by Schiller,[896] an Ascaris had gained access to the biliary passages after an operation for cholelithiasis (with distension of the gall-bladder and formation of a fistula); it had kept itself alive here eighteen days and was extracted from the fistulous opening. Epstein[897] confirms the correctness of the explanation of the mark of strangulation in an Ascaris in Mertens’[898] case (in a woman, aged 30, there was first icterus, later ascites, anasarca, swelling of the liver, then the discharge of two dead Ascaridæ, one of which exhibited a constriction somewhat behind its centre; after that there was rapid improvement in all the symptoms); in his case there was icterus in consequence of closure of the ductus choledochus by an Ascaris. After the discharge of the worm the symptoms persisted; one of the Ascaridæ had a typical strangulation mark. From the observation recorded by Vierordt[899] it follows that, without doubt, mature females can penetrate into the liver and there deposit eggs; in addition, that such eggs appear exceptionally to undergo segmentation. A unique feature in this case consisted in the exclusive discharge of immature worms almost regularly throughout an interval of nine weeks; this cannot be explained from our present knowledge of the biology and pathology of the Ascaridæ. These worms clearly make their way from the intestine outwards, through the opening into the duodenum of the common bile-duct, and unquestionably the fully developed Ascarides, with the aid of their conical head end, are enabled gradually to penetrate the wall of the ductus choledochus (Quincke[900]), and gain access to the gall-bladder, the hepatic duct and its branches.

The changes in the biliary passages and the liver are, on the one hand, the mechanical results of a partial or total obstruction to the flow of the bile, and, on the other, of inflammatory processes. The blocking of the common bile-duct and of the trunk of the hepatic duct leads to the well-known symptoms of biliary engorgement; protracted continuance of this condition has, as its sequela, general distension of the whole biliary system and degenerative destruction of the liver-cells. If the Ascaris is situated at some other part of the biliary system, its presence causes a partial arrest of the flow of bile, with the corresponding sequelæ. Many Ascarides perish in the ductus choledochus, and here and in the gall-bladder they may supply the nucleus of a gall-stone; deeper in the liver this does not appear to happen; the dead Ascaridæ here undergo a kind of maceration, disintegrate, and may be completely absorbed; in many cases the worms continue to live for a very long time in the biliary passages. When the worms infect the biliary passages through the invasion of intestinal bacteria, liver abscesses arise (Dauernheim,[901] Saltykow[902]). Leer[903] goes so far as to maintain that Ascaridæ may be the second most frequent cause of liver abscesses. That Ascaris in the pancreas may simulate liver abscess in a remarkable fashion is shown by Vierordt’s[904] observation, which is quite unique, while Ascaridæ have been found to occur in isolated instances in the excretory ducts of the pancreas and in its branches, where they have remained living for a long time.

It is no rare occurrence for Ascaridæ, in consequence of their migration into the stomach, to be ejected by the act of vomiting, and in such way to gain access into the upper air passages, or to find their way during sleep into the nose or accessory sinuses (Mosler and Peiper[905]) without giving rise to special symptoms. For example, Troja[906] found in the frontal sinus of a cadaver a large coiled-up Ascaris which occupied the whole cavity. Wrisberg[907] made the same observation in the cadaver of a boy. Deschamps[908] and Fortessin[909] mention an Ascaris being met with in the antrum of Highmore. Observations of the discharge of living or dead Ascarides from the nose are frequently recorded. To this class belongs the case mentioned by Albrecht,[910] in which an Ascaris was removed from the nose of a girl, aged 7; also the case recorded by Benievini,[911] from the nose of one of whose friends a worm escaped; he had suffered from the most violent headaches, fainting fits, dimness of vision and vomiting; after the escape those untoward symptoms disappeared. Similar records have been made by Forest,[912] Lanzoni,[913] Langelott,[914] Tulpe,[915] Reisel,[916] Fehr,[917] Bruckmann,[918] Bahr,[919] Slabber,[920] Lange,[921] and Chiari.[922] A rarer case is that recorded by Haffner,[923] that of a child, aged 4, in whom an Ascaris reached the nasal cavity through the act of vomiting, and from there it gained access through the naso-lachrymal duct and the inferior lachrymal sac into the lower punctum lachrymale, from which half of it protruded.

Among the rarer causes of the occurrence of strange bodies in the pharynx and naso-pharyngeal cavity, Jurasz[924] mentions in the first place vomiting, which may afford opportunity for the more solid bodies of the stomach contents, and even parasites of the digestive tract, especially Ascaridæ, to become firmly lodged in the pharyngeal or naso-pharyngeal cavity. Ascaridæ may obtain access from the naso-pharyngeal cavity to the middle ear by way of the Eustachian tube, as has been observed by Reynolds[925] and Wagenhäuser[926]; in the case recorded by Turnbull[927] (girl, aged 8, with pains in her ear) the Ascaris apparently reached the external auditory meatus by the same route.

The irritation of the larynx and air passages by Ascaridæ is far more dangerous than their penetration into the nose and naso-pharyngeal cavity, because not only are attacks of suffocation, but sudden suffocation thereby induced. Oesterlein[928] records a fatal attack of choking from Ascaridæ in the trachea. In a case recorded by Smyly[929] of a boy, aged 3 1/2, tracheotomy for extreme asphyxia was performed without relief. At the post-mortem the cause of the asphyxia was found to be an Ascaris in the trachea. Fürst[930] collected twenty-five observations of invasion of the larynx and trachea by Ascaris. Mosler[931] reports the case of a patient with aphonia and dyspnœa from whose larynx an Ascaris was removed. Donati[932] reports a case of four Ascarides in the larynx, and Cerchez[933] of asphyxia from Ascarides in the larynx or trachea. Wagner[934] records the case of a boy, aged 8, in whom a coil of worms was ejected from the stomach by vomiting; the mass blocked the entrance to the larynx and led to death from suffocation. A case similar to that recorded by Smyly is communicated by Rabot[935]; it was that of a child who underwent tracheotomy for diphtheria, and who was not relieved by the operation; when, however, an Ascaris appeared in the cannula and the parasite was removed the child breathed well. In Negresco’s[936] case, that of a boy, aged 3, an Ascaris gained access to the larynx and from there into the trachea, and a fatal issue from asphyxia resulted.

The route by which Ascaridæ obtain access to the urinary passages must remain undecided. Schlüter[937] treated a woman, aged 60, with retention of urine. Upon catheterization the hinder end of an Ascaris hung out from the catheter opening; the anterior end was fixed in the tube and the lumen was obstructed. Perhaps in the female sex Ascaridæ travel from the gut into the vulva and from there into the bladder, as they have already been observed in the vagina, where they cause troublesome symptoms (pruritus pudendi).

The diagnosis of ascariasis is not in general difficult; now and then the worms are discharged spontaneously; if not, the ova, which cannot be mistaken, can easily be detected in the fæces upon microscopical examination. Epstein’s[938] method—namely, on every occasion to obtain fresh material for examination—is much to be recommended. This consists in introducing a Nelaton’s catheter into the rectum with a rotatory motion and then drawing it out. A small portion of fæces forced into the catheter opening is more than sufficient to demonstrate the presence of ova of the parasites upon microscopical examination of a preparation.