With regard to the toxic action of Oxyuris there is only the single record of Hartmann,[579] who noticed the disappearance of epileptic fits and psychic disturbances in a girl, aged 13, after the removal of Oxyuris. Nervous disturbances and blood changes can but rarely be attributed to Strongyloides. Silvester[580] and Valdes[581] report on giddiness, headache and anuria in cases observed by them; whether the eosinophilia recorded by Bücklers[582] and Bruns[583] is due to the toxin of Strongyloides must remain an open question.

Reference has already been made to the possibility that intestinal ciliates (Balantidium coli) can also produce toxins.

The contents of echinococcus cysts appear to contain a substance only moderately toxic, giving rise to urticaria, in a series of cases where the fluid has escaped into the abdominal cavity (during puncture). D. Müller[584] has collected nine such cases out of the literature, to which may be added six cases of Finsen[585] in which the escape of fluid into the peritoneal cavity led to severely itching urticaria, which usually disappeared again after one or two days. On one occasion, indeed, urticaria occurred after rupture into the pleural cavity. In the case recorded by Caffarena[586] of echinococcus of the right lobe of the liver, widespread urticaria developed as the result of the exploratory puncture. In the case of an echinococcus of the liver rupturing into the abdominal cavity La Spada[587] ascribed the symptoms leading to death to toxic influence while the peritoneal symptoms were less marked. Eosinophilia in hydatid disease is slight according to the investigations of Bindi[588] and Santucci,[589] and is, according to Welsh and Barling,[590] no certain sign of echinococcus; it is independent of the age, sex and temperature of the patient, but upon rupture of the cyst eosinophilia invariably sets in.

The question as to the importance of helminthes in relation to certain diseases of the gut requires special discussion, but it concerns only Ascaris lumbricoides, Oxyuris vermicularis, and Trichocephalus dispar, and the question of appendicitis first of all. The entrance of intestinal parasites into the vermiform appendix was already known to medical men in the fifties of last century, as is shown by the works of Merling[591] (1836), Zebert[592] (1859), Platonor[593] (1853), and Schachtinger[594] (1861). Most of these authors have considered intestinal worms, together with other foreign bodies, to be the cause of appendicitis. As regards the part played by these intestinal parasites in the etiology of appendicitis, so much discussion has taken place during the last few years that it is worth while to give a résumé of the later views on this question, even though at the outset it must be admitted that the matter is not cleared up. Bergmann[595] records a case in which an Ascaris perforated the appendix and got into the peritoneal cavity.

Strümpell[596] reckons among the symptoms of Trichocephalus the possibility of a “typhlitis.” On account of the marked sensitiveness of the ileo-cæcal region, Boas[597] mentions the possibility of confusing it with appendicitis. Still[598] regards Oxyuris as a principal cause of catarrhal affections of the appendix. Arboré-Rally[599] regarded severe symptoms of appendicitis in a boy, aged 10, as due to Ascarides. In all cases of appendicitis Metschnikoff[600] requires a microscopical examination to be made for eggs, and considers treatment for worms carried out otherwise as a cause of the frequency of perityphlitis. Matignon[601] does not agree with this opinion, as in spite of the extraordinary frequency of intestinal worms in China, he has only seen one case of appendicitis in four and a half years, and Des Barres[602] expresses himself in similar fashion. Out of twenty-one cases of appendicitis Kirmisson[603] discovered the ova of Trichocephalus eighteen times and the ova of Ascarides in three of these cases; in twelve cases of enteric fever the examination for eggs was negative nine times. Moty[604] considers Oxyuris to be the sole cause in his three cases of appendicitis. Girard[605] ascribes to Trichocephali the rôle of more or less septic foreign bodies which may bring about the entry of intestinal bacteria into the appendix, and Triboulet[606] describes a case of appendicitis which he considers was due to Ascaris. In Morkowitin’s[607] case numerous Oxyuris had clearly caused the appendicitis. von Genser[608] records the case of a boy, aged 5, who was operated on for appendicitis, and who passed through the operation wound a living Ascaris on the eighteenth day after the operation. In the first case communicated by Schiller[609] the disappearance of the typhlitic swelling after the discharge of the Ascarides pointed to the etiological significance of the parasites, and the same obtained in a further case published at an earlier date by Czerny and Heddäus.[610] In a case abstracted by Kaposi[611] Trichocephali appear to have been a contributory cause in the production of the appendicitis. In a further case reported by Schiller, where the appendix was removed, it was shown that Oxyuris had given rise to a pronounced appendicular colic. In a girl, aged 13, who died from diffuse peritonitis, Schwankhaus[612] found that an Ascaris had perforated the appendix. Ramstedt[613] found in an extirpated appendix a whole “tangle” of Oxyuris, and believes in the possibility of their having provoked the inflammation; he recommends an examination for entozoa before the operation, without, however, after Metschnikoff’s example, substituting worm treatment for the operation. Rostowzeff[614] ascribes only a minimal direct etiological significance to intestinal worms in the origin of appendicitis; in 163 cases he found worms in three instances. Wirsaladze[615] expresses himself in a similar fashion. Oppe[616] observed Oxyuris six times in excised appendices, and emphasizes the opinion that in appendicitis the question of a worm cure ought to be taken into consideration. Ascaris and Oxyuris, if no contra-indication exists, may be expelled, but in the case of Trichocephalus, which frequently defies all expulsive treatment, no attempt should be made, but operation proceeded to forthwith. In a case briefly reported by Hanau[617] Oxyuris was undoubtedly the etiological starting-point; in a case of Galli-Vallerio[618] Oxyuris and Trichocephalus. In the opinion of Ssaweljews[619] in some cases of appendicitis, in addition to other causes, intestinal parasites play a prominent part. The case recorded by Nason[620] is an interesting one; in this an Ascaris in the appendix became twisted with it round a coil of gut, causing obstruction. Spieler[621] argues against the underestimation by many authors as to the part played by intestinal worms in producing appendicitis, although he also does not regard them as a frequent, to say nothing of an exclusive, cause of the disease. In a case recorded by Bégonin[622] fifteen Oxyuris were found in the excised appendix (the mucosa showed some ulceration), and in another recorded by Putnam[623] twenty Oxyuris were present in the appendix, in which there was no evidence of any change. The standpoint Schilling[624] takes is to the effect that entozoa irritate the mucosa and can increase an already existing inflammation, but he considers it very questionable whether they can produce appendicitis. Blanchard[625] assumes the possibility of a secondary infection arising from lesions of the mucosa produced by helminthes (Ascaris and Oxyuris). Moore[626] considers Trichocephalus the excitant of the appendicitis in his case. In a second case of appendicitis recorded by Auley[627] operation became unnecessary owing to the passage of the Ascaridæ. Page’s[628] case is an interesting one; it was that of a man who came up for operation with a diagnosis of appendicitis. On incising the abdominal wall numerous Ascarides were found at the base of the wound, lying in cavities; even after eight days Ascarides escaped from the wound. The author assumes there was a perforation of the gut wall; it is strange that the worms were able to exist a proportionately long time in the muscular tissue. Schoeppler[629] states that there is the danger of an appendicitis even after the death of an Oxyuris that has found its way into the appendix. Oui[630] met with two specimens of Trichocephalus which had become embedded by their thin ends deep in the mucosa. Frangenheim[631] is not in a position to pronounce any opinion as to what part intestinal parasites play in the etiology of appendicitis. In a case recorded by Kahane[632] many Trichocephali were found partly free in the appendix and partly embedded in the mucosa; microscopically appendicitis was diagnosed. At a laparotomy for salpingitis Heekes[633] found the appendix elongated, thickened, and containing about eleven Oxyuris without the mucosa being in any way changed. In one case Andrews[634] claims Ascarides to have been the direct cause of the appendicitis. The literature dealing with this question, so important in our time, has been collected almost without any omissions, but, unfortunately, no decisive opinion as to the significance of parasites in appendicitis can be inferred from it. The vexed question whether intestinal parasites, especially Ascaris, are able to penetrate the intestinal wall is just as little finally decided. Leuckart,[635] Heller,[636] Mosler and Peiper,[637] Henoch,[638] Davaine,[639] Küchenmeister,[640] and Bremser[641] are opposed to the idea that the healthy intestinal wall can be penetrated by intestinal worms, especially Ascarides, whilst a whole series of other authors are of the opinion that even the healthy intestinal mucosa can be perforated. Among these is numbered Mondière,[642] who is of the opinion that Ascaris, by violent pressure against the mucosa, forces it so much apart that it is enabled to escape through the gap thus formed into the peritoneal cavity; this opinion is shared by v. Siebold.[643] Rokitansky[644] considers perforation of the gut by Ascaris as at least a rare occurrence. Gerhardt[645] does not doubt that the worms can actively perforate the intestine. Cases like those of Abrault,[646] Apostolides,[647] Marcus[648] (recorded by Perls as a valid example of “ascaridophagous” gut perforation), Wischnewsky,[649] Galvagno,[650] Salieri[651] certainly show that perforation of the healthy gut wall cannot be denied, but at the same time that this occurrence, compared with the frequency of Ascaridæ, should be regarded as exceedingly rare. It is another matter as to whether it is possible for the worms to penetrate an intestinal wall already diseased, especially when ulcerated; a whole series of observations are in favour of this. In Lini’s[652] case (fifty-six Ascarides escaped from the umbilicus of a girl, aged 7), in Gräffe’s[653] (eighty Ascarides escaped from an inguinal tumour), in Nicolino’s[654] (perforation of the intestinal wall with strangulated hernia), in Liesen’s[655] (a living Ascaris in the peritoneal cavity in a woman suffering from a peritoneal abscess)—in these it is clear that disease processes in the intestine preceded the exit of the worms. In a case described by Boloff[656] the Ascarides appear to have produced, by forming a tight coil, necrosis of the gut with perforative peritonitis. In a case recorded by Lutz[657] the perforative peritonitis was without doubt provoked by Ascaris, and in one by Schiller[658] the Ascaris had clearly gained access to the peritoneal cavity through a gunshot wound opening. In a case observed by Rehn[659] the worm probably entered through a gangrenous portion of the intestine in a hernial sac. Broca[660] is unable to determine whether in his case the intestinal perforation was primary (a worm escaped from the abdominal wound about two months after a laparotomy for suppurative peritonitis). The case reported by Lutz[661] is of special interest: it was that of a young man who had shot himself in the region of the abdomen, and who died after fifteen days. At the post-mortem two Ascarides were found in the pulmonary artery; they had probably escaped from the intestine, and had gained access to the inferior vena cava. Froelich[662] assumes that in his case (a boy, aged 11) the Oxyuris were able to penetrate the whole intestinal wall, but Vuillemin[663] considers this improbable, and is more inclined to think that the Oxyurides penetrated the rectum at small ulcerated points, and thus gained access to the perirectal connective tissue. In females Oxyuris not only have the power of penetrating far into the sexual organs (Marro[664]), and perhaps causing a parasitic endometritis (Simons[665]), but also clearly of gaining access to the peritoneal cavity by way of the tubes, as is to be assumed in the case recorded by Kolb[666] (that of a woman, aged 42, in whom post mortem nodules were found over the peritoneum of Douglas’s pouch, in which the pressure of encapsuled Oxyuris could be demonstrated), in that reported by Chiari[667] (adult Oxyuris in Douglas’s pouch) and by Schneider[668] (an Oxyuris encapsuled in the pelvic peritoneum). Sehrt’s[669] case is worthy of attention; in this an abscess was found in the omentum with numerous Ascaris ova in the pus and a nodular lesion of the peritoneum, with Ascaris ova encapsuled in the nodules. Massive accumulation of Ascarides may give rise to a complete occlusion of the gut. Such an occurrence is not so surprising as might be thought when one reflects that the number of Ascarides in one individual may amount to several hundreds. For instance, one boy evacuated within a single day 600 Ascarides (Fauconneau-Dufresne[670]) and within three years 5,126 worms. In the case recorded by Tschernomikow[671] a boy, aged 2 1/2, evacuated during a day 208 worms, partly through the stomach, partly through the intestine. Coil-formation of such masses of Ascarides renders possible not only constipation, but also complete obstruction with symptoms of ileus, as shown by the five cases quoted by Mosler and Peiper,[672] as well as from observations made by Raie,[673] Schulhof,[674] Rehberg,[675] Rocheblave,[676] Heller,[677] Leichtenstern,[678] Huber,[679] and Wilms.[680] In two cases of Black[681] and Parkinson[682] the intestinal obstruction was caused by a coil of tapeworms.

In the earlier history of medicine the helminthes played a great part as the excitants of many intestinal diseases and of enteric as well. Even if to-day they no longer be regarded as such, the conception that they represent the predisposing factor in typhoid infection through the injury they inflict on the mucosa (Guiart,[683] Blanchard,[684] Vivaldi and Tonello[685]) must not be summarily rejected. Vivaldi and Tonello found helminthes in 80 per cent. of their typhoid patients, numbering among these Trichocephalus dispar, Oxyuris vermicularis, Ancylostoma duodenale, and Ascaridæ. The report of Leuckart[686] is here worth citing, to the effect that Thiebault never failed to find Trichocephalus in his cholera patients at Naples. Blanchard[687] goes so far as to express the desire that in every febrile affection of the intestine an anthelmintic treatment with thymol should be undertaken as early as possible, even before learning the results of serum diagnosis.

The lesions of the liver and pancreas due to Ascaridæ are briefly discussed in the chapter on Ascariasis (p. 687).

A discussion of the intestinal helminthes from the clinical and therapeutical point of view follows these general considerations.

Dibothriocephalus latus.

From what is known as to the development of Dibothriocephalus latus, the way by which man is infected is self-evident: infection can only take place through the ingestion of insufficiently cooked fresh-water fish (pike, burbot, perch, grayling and vendace); what degree of temperature is necessary to kill the larval forms is still unknown. Dibothriocephalus latus lives in the small intestine of man, alone or in some numbers, frequently also together with Tænia solium. The proglottides are passed always united in large pieces, the ova are deposited through the uterine pore, while the worm is still in the intestine, so that they are easily found in the fæces. The proglottides are so characteristic that they cannot be confused with those of other species. In reference to whether age or sex is spared by D. latus, it is not possible to make any definite statement, especially so far as the endemic area is concerned, whether a person resides in it continuously or visits it, so long as his habit of life is in accordance with those of the country. Bendix[688] certainly emphasizes the fact that early childhood is as a rule immune: his case was that of a child, aged 4 1/2 years.