As commonly observed in the human body our young Trichinæ appear as spirally-coiled worms in the interior of small, globular, oval, or lemon-shaped cysts, which latter appear as minute specks scarcely visible to the naked eye. These specks resemble little particles of lime, being more or less calcareous according to the degree of degeneration which their walls have undergone. In shape and general aspect they are not altogether unlike the eggs of certain nematoid worms, but their size alone sufficiently distinguishes them. They measure on an average 178″ in length by 1130″ in breadth. The organised capsules are not essential to the further development of the parasite, and are rather to be regarded as abnormal formations, or rather, perhaps, as products resulting from an effort of nature to protect and thus prolong the life of the occupant. They are frequently altogether wanting. The capsuled Trichinæ measure 123″ in length by about 1630″ in breadth. When fully formed they not only exhibit a well-marked digestive apparatus, but also reproductive organs, which are often, indeed, sufficiently developed to determine the sex.
Notwithstanding the large number of experiments that have been more or less recently made by investigators, little or nothing has been discovered calculated to disturb the conclusions set forth by Leuckart, who writes as follows:—“(1) Trichina spiralis is the juvenile state of a little round worm, previously unknown, to which the generic title of Trichina must remain attached. (2) The sexually mature Trichina inhabits the intestinal canal of numerous warm-blooded animals, especially mammalia (also of man), and constantly in great numbers. The duration of its life extends from four to five weeks. (3) At the second day after their introduction the intestinal Trichinæ attain their full sexual maturity. (4) The eggs of the female Trichinæ are developed within the uterus of the mother, into minute filaria-like embryos, which, from the sixth day, are born without their egg-shells. The number of young in each mother-worm is at least from ten to fifteen thousand. (5) The new-born young soon after commence their wandering. They penetrate the walls of the intestine and pass directly through the abdominal cavity into the muscles of their bearers, where, if the conditions are otherwise favorable, they are developed into the form hitherto known. (6) The directions in which they proceed are in the course of the intermuscular connective tissues. (7) Only the striped muscle (that of the heart excepted) contains Trichinæ. The majority of the wandering embryos remain in those sheathed muscular groups which are nearest to the cavity of the body, especially in those which are smaller and most supplied with connective tissue. Speaking generally, their number decreases with the distance from the abdomen, being, however, more numerous in the anterior half of the body. (8) The embryos penetrate into the interior of the separate muscular bundles, and here already, after fourteen days, acquire the size and organisation of the well-known Trichina spiralis. (9) Soon after the intrusion of the parasite the infested muscular fibre loses its original structure, the fibrillæ collapse into a finely granular substance, whilst the muscular corpuscles change into oval nucleated cells. (10) The infected muscular bundle retains its original sheathing up to the time of the complete development of the young Trichinæ, but afterwards its sarcolemma thickens, and begins to shrivel at the extremities. (11) The spot inhabited by the rolled-up parasites is converted into a spindle-shaped widening, and within this space, under the thickened sarcolemma, the formation of the well-known lemon-shaped or globular cysts commences by a peripheric hardening and calcification. This degeneration commences several months after the wandering. Immature muscle-Trichinæ are not capable of producing infection. (12) The migration and development of the embryos also take place after the transportation of impregnated Trichinæ into the intestines of a new host. (13) The further development of the muscle-Trichinæ into adult animals is altogether independent of the formation of the calcareous shell, and occurs as soon as the former have reached their completion. (14) Males and females are already recognisable in their larval state. (15) The immigration of the Trichina-brood in masses produces very grave or even fatal consequences, such as peritonitis (from the embryos perforating the intestinal walls), pain, and paralysis (resulting from the destruction of the infected muscular fibres). (16) The infection of man occurs especially through swine. (17) The muscle-Trichinæ are so capable of resistance that they are by no means in all cases destroyed by the ordinary methods of roasting, cooking, pickling and smoking. (18) As a rule, swine obtain Trichinæ from rats, to which latter we also as the natural bearers have to convey them. Microscopic examination of flesh is, therefore, urgently recommended as a public preventive against all danger from Trichinæ.”
As a summary the above conclusions are well nigh exhaustive; but whilst I purposely avoid entering into mere clinical details, there are points of hygienic interest to which I must allude. Thus, as regards the number of larval Trichinæ in any one “bearer” at a time, this, of course, must be extremely variable, but it may amount to many millions. In one of the cats on which Leuckart experimented, he estimated a single ounce of its muscle-flesh to harbour no less than 325,000 Trichinæ. I find that a relatively similar degree of infection in an ordinary human “bearer” would yield thirty millions. In the case of one of my own experimental animals, a pig, I reckoned that there were at least sixteen millions of Trichinæ. The larvæ were about ten months old and enclosed within perfectly formed capsules; nevertheless, the animal had never displayed any symptom of irritation. In a trichinised human subject, examined by Dr Thudichum, it was estimated that 40,000,000 parasites were present. My own estimate, calculated from specimens of muscle obtained from the same case, gave 100,000,000 as the approximate number of worms present. In the only outbreak of Trichinosis occurring in England, details of which will be given further on, I found that the flesh of the hog that had caused the local endemic contained upwards of 80,000 Trichinæ to the ounce. The consumption of a pound of such flesh would be capable of producing a collective progeny of something like 400,000,000 within the human “bearer.”
In the year 1865 I conducted a series of experiments upon upwards of a score of animals, including seven birds, the latter all yielding only negative results. So far as muscle-Trichinæ were concerned my experiences accorded with those of Professors H. A. Pagenstecher and C. J. Fuchs, at the Zoological Institute in Heidelberg. These experimenters found that the ingested muscle-Trichinæ acquired sexual maturity within the intestinal canal of their avian “hosts;” but they never found young Trichinæ in the muscles of the birds, nor did they perceive any evidences of an attempt on the part of the escaped embryos to effect a wandering or active migration on their own account. Clearly, if the bird’s intestinal canal were a proper territory for the residence of sexually mature Trichinæ, we should have found abundance of wandering non-encapsuled flesh-worms and also sexually-immature muscle-Trichinæ enclosed in well-formed capsules. Not a few persons still entertain the notion that Trichinæ are liable to infest all kinds of warm-blooded, and even also many kinds of cold-blooded animals, such as reptiles and fishes. Certain nematodes found in earth-worms have been described as Trichinæ; and consequently, pigs and hedgehogs were said to become trichinous through eating these annelids. The minute flesh-worms described by Bowman from the muscle of the eel are not true Trichinæ, any more than the somewhat similar parasites which Eberth found to infest the muscles of the frog. The same may also be said of Dr Salisbury’s urinary Trichinæ, which are the larvæ of Filaria Bancrofti.
Deducting the seven birds, and also six other animals where no examination after death was possible, I ascertained the result of my worm-feedings in sixteen instances. Nine of the experiments were entirely successful, the infected animals comprising four dogs, two cats, one pig, one guinea-pig, and a hedgehog.
Carnivorous mammals, especially those subsisting on a mixed diet, are the most liable to entertain Trichinæ, but it is quite possible to rear them in herbivora. Thus, Pagenstecher and Fuchs succeeded in rearing muscle-Trichinæ in a calf, and they found three female intestinal Trichinæ in a goat, but apparently no muscle-flesh-worms, although twenty-seven days had elapsed since the first feeding with trichinised rabbit’s flesh. In three sheep on which I experimented no trace of Trichinæ could be found. There is no practical need for any further experiments on herbivora, for it is quite clear that, in their natural state, herbivorous mammals can seldom have an opportunity of infesting themselves, whilst the reverse is the case with swine, carnivorous mammals, and ourselves. Because many quadrupeds become trichinous, it does not follow that all mammals are liable to be infested. In the case of most parasites we find the species limited to a larger or smaller number of hosts. On the other hand, in not a few cases, the range of the entozoon is limited to a single territory or host.
In conducting the experiments above mentioned I was assisted by Professors Simonds and Pritchard, of the Royal Veterinary College. As they were the only researches conducted on any considerable scale in England, I subjoin a few details of them. Dr Thudichum’s experiments were, I believe, confined to rabbits.
Exps. 1 and 2.—On the 15th of March, 1865, an ounce of flesh containing Trichinæ was administered by myself to a black bitch. The dog being destroyed five days subsequently, neither intestinal nor muscle-Trichinæ were discovered. It was thought that the dog had thrown up the bolus, which was strongly saturated with chloride-of-zinc solution. The bolus consisted of a portion of the pectoralis major of a subject brought to the dissecting-room at the Middlesex Hospital. The cysts were highly calcified, but the majority contained living embryos, which were quite unaffected by the zinc solution injected into the body to prevent decomposition. At the same date a small white puppy was experimented on and examined with precisely the same results. In either case it was too early to expect muscle-flesh-worms to have become developed.
Exp. 3.—Half an ounce of the same trichinous human flesh was given (at the same date) to a black-and-tan puppy reared at the Royal Veterinary College, a second “feeding” being administered on the 21st of March, or six days after the first. In this case Mr Pritchard, who fed the animal, took the precaution to chop the muscle into small pieces, and to mix it with other food, in order that the flesh might be the more readily retained in the stomach. The puppy was not destroyed until the 15th of the following June, when, on examination, numerous encysted but non-calcified muscle-Trichinæ were found in all the voluntary muscles subjected to microscopic scrutiny.
Exp. 4.—An ounce of the same flesh was given to a dark-colored pig on the 15th of March, and again on the 20th, several other “feedings” being also administered during the month of April, 1865. It was destroyed on the 16th of May, but no Trichinæ were detected.
Exp. 5.—An ounce of the same human muscle-flesh administered to a small sheep (which was subsequently killed on the 29th of June) also produced negative results.
Exps. 6 and 7.—“Feedings” were at the same time administered to a rat and mouse. The mouse died on the 2nd April, when I examined its muscles without success. On the following day the rat unfortunately made its escape, but whether trichinised or not cannot be said.
Exp. 8.—An ounce of trichinous human flesh was given to a donkey, in the form of “balls,” on the 20th of March; and during the month of June four other separate “feedings” with trichinous dog’s flesh were also administered. The animal was removed from the College without the result being ascertained.
Exp. 9.—From the 15th to the 20th March, 1865, inclusive, three small Trichinæ “feedings” were likewise administered to a guinea-pig. This little animal was not destroyed until the 15th of the following June, when a positive result was obtained. The pectoralis transversus and other muscles were found to harbour a considerable number of encysted Trichinæ.
Exp. 10.—On the 20th March, and again on the 21st (1865), “feedings” from the same human subject were administered to a hedgehog. On the 26th of April the animal seemed to be attacked with symptoms of Trichinosis. It refused food, kept its head extended, and the eyelids closed. On the 27th it appeared much worse, and on the morning of the 28th it was found dead. On the 29th I examined the flesh, and found abundance of living Trichinæ in the muscles. The capsules were very thin and transparent. A few days later Mr Simonds also examined the flesh, and confirmed this result.
Exps. 11 and 12.—Two chickens were fed, on the 21st of March, with the same material. One of the birds died on the 24th, when I examined the intestines and detected one or two very minute nematodes, which, at the time, I believed to be imperfectly developed Trichinæ, but subsequently saw reason to alter my opinion. The other bird died on the 3rd of April, and certainly contained no muscle-Trichinæ.
Exp. 13.—On the 22nd and 23rd of March “feedings,” amounting to an ounce of flesh in all, were given to a mole. This animal was returned to the care of Mr Charles Land, who had previously sent it to the Veterinary College. He subsequently reported that, after observing the mole to be “working” for two or three days, he lost all trace of it, and concluded that it had either escaped or was dead.
Exp. 14.—On the 1st and 2nd of May portions of the left fore extremity of the hedgehog (in which we had successfully reared Trichina from the Middlesex-Hospital subject) were offered by Mr Simonds to a cat. It ate the flesh very readily, consuming the entire limb. On the 15th of the following June the cat was killed, when living Trichinæ were found within all the muscles which we examined.
Exp. 15.—At the same dates a young terrier dog was similarly treated, but did not take the “feeding” so readily. In this case the left hind extremity of the hedgehog was employed, and what was not eaten voluntarily was forcibly introduced. On the 1st of June the dog was attacked with “distemper,” and died on the 8th of the same month. On examination we found several living Trichinæ in the sterno-maxillaris and other muscles. Some of the parasites were encysted.
Exp. 16.—From the 9th to the 12th of June inclusive four separate worm-feedings with the flesh of the trichinised terrier-dog were administered to a crow. The bird was killed some months afterwards and sent to me for examination. Its muscles were entirely free from Trichinæ.
Exp. 17.—From the 9th to the 17th of June inclusive seven separate worm-feedings were administered to a pig. One of the “feedings” was with the trichinised guinea-pig’s flesh, the others from the dog. This animal was not destroyed until the 4th of April, 1866, when all the muscles which I examined were found extensively infested with Trichinæ. There were probably not less than 16,000,000 present, all being alive and enclosed within perfectly-formed capsules, none of which latter exhibited any traces of calcareous deposition.
Exp. 18.—Four separate feedings with trichinous dog’s flesh were likewise, at the same dates as the foregoing, administered to a rat. This experimental animal, however, like the one previously mentioned, contrived to make its escape. I fear it was well trichinised.
Exp. 19.—About the same date trichinous “feedings” were given to a black puppy (bred at the Veterinary College). The dog was killed on the 18th of August, 1866, having also been made the subject of an echinococcus-feeding, when I found abundance of encysted Trichinæ within the voluntary muscles.
Exp. 20.—Four separate worm-feedings with the flesh of the trichinised guinea-pig were given to a sheep on the 15th, 16th, 17th, and 19th days of June, 1865. The experimental animal was destroyed on the 29th of the same month, but the result was negative.
Exps. 21 and 22.—“Feedings” with the guinea-pig’s flesh—four in the one case and three in the other—were also administered by Mr Simonds (from the 15th to the 19th of June, inclusive) to a chicken and goose respectively. These birds were destroyed some months afterwards and sent to me for examination, but the most careful scrutiny failed to detect any Trichinæ within their muscles. The goose was cooked and eaten without the slightest hesitation. The chicken I found too tough for consumption.
Exp. 23.—On the 28th of March, 1866, I obtained a small quantity of muscle from a highly trichinised German subject, who died from the effects of an accident at the London Hospital the day previous. The case was fully reported by Dr Thudichum in a new journal, called ‘Scientific Opinion’ (No. 4, April 25th 1866, p. 55). During the same day (at 2.30 p.m.) I fed a dog with part of this human flesh. On the morning of the 31st I killed the dog, and examined the intestinal canal (at 11.30 a.m.), which revealed the presence of sexually-mature living Trichinæ. The males (of one of which I retain an accurate figure) displayed the characteristic bilobed caudal appendage, leaving no doubt as to their source and nature. I have mentioned the precise time of the experiment, in order to show that a period of sixty-nine hours proved amply sufficient for the development of the young muscle-flesh-worms of the human subject into the sexually-mature adult Trichinæ of the dog.
Exp. 24.—With another portion of this human flesh (taken from the muscles of the tongue) in which the Trichinæ were extraordinarily abundant, I fed a cat. In about ten days the animal showed the most marked symptoms of trichinosis. It refused to eat; the eye lost its lustre; the body became very thin, and I thought the animal would die. By very great care, keeping it warm before the fire, and subsequently inducing it to take a little milk, the creature improved, gained flesh, and eventually recovered. About three months afterwards I destroyed this cat, when on examining the panniculus carnosus, latissimus dorsi, and other superficial muscles, I found great quantities of well-developed, capsuled Trichinæ. Although the animal had swallowed scarcely a quarter of an ounce by weight of the infested flesh, yet thousands of parasites had been propagated and dispersed throughout its muscular system. In this way the helminthiasis nearly proved fatal to my cat. As has been already stated, Dr Thudichum, who I believe had an opportunity of examining the corpse of this trichinised German, estimated the number of parasites in his body at 40,000,000. I do not think this estimate likely to be exaggerated, for if all the flesh had been infested to the extent I found to obtain in respect of the muscles of the tongue, I believe 100,000,000 would have been nearer the mark. In places the point of a needle could scarcely be thrust between the capsules, so closely were they agglomerated.
Exp. 25.—From the 19th to the 25th of April, 1866, inclusive, daily administrations of trichinous pork, in the form of bolus, were made to a sheep by Mr Pritchard. The Trichinæ were obtained from one of our experimental animals at the Veterinary College, about two ounces of the flesh being given at each feeding. The flesh of this sheep (destroyed in the following November) failed to give any indication of the presence of parasites.
Exps. 26 and 27.—About the same time, and occasionally at intervals extending over a period of five weeks, Mr Pritchard also fed two young fowls with the same trichinous pork. Towards the close of October, 1866, both birds died, when Mr Pritchard carefully examined the flesh of them, but failed to find any trace of Trichinæ.
Exps. 28 and 29.—From April 2nd to the 9th of the same month, 1866, inclusive, feedings with trichinous pork were likewise given to two dogs. These animals were destroyed and examined by Mr Pritchard in November, 1866, but the result appears to have been negative.
It is perfectly certain that the infection of man by Trichina is invariably due to the ingestion of verminiferously diseased meat, and as remarked in my ‘Lectures,’ whenever the parasites are taken in large numbers unpleasant symptoms soon show themselves in the infested person. There is, first of all, restlessness, loss of appetite, and more or less prostration. This is succeeded by rheumatoid pains in the limbs, with the frequent accompaniment of considerable swelling. The pain is not situated in the joints, but in the intermediate soft parts. In severe cases the limbs are drawn up and half bent, as in instances of severe and continued cramp. Sometimes the suffering is excruciating and unbearable, patients having been known to request the surgeon to put an end to their lives. In the worst forms of the malady death rapidly ensues from diarrhœa and exhaustion. If the parasites have gained admission to the muscles all hope of destroying them is at an end; but if a person suspects himself to have eaten diseased or trichinised meat he should lose no time in seeking professional assistance, seeing that the administration of suitable anthelmintics might be the means of saving his life, whereas a few days’ delay would probably prove fatal. So long as the worms remain in the stomach or intestinal canal they can be got rid of, but when once the trichinal brood have invaded the flesh then they cannot be expelled. As remarked in my ‘Entozoa,’ it is easy to perceive that although, in the majority of instances, Trichiniasis does not cause death, yet the percentage of fatal cases is by no means insignificant.
The notion that particular breeds of swine are more liable to be infested than others is absurd, since infection must be due to the facilities offered for swallowing garbage, especially dead rats. According to Drs Belfield and Atwood 8 per cent. of slaughtered American swine contain Trichinæ. In infested hogs they found from 35 to 13,000 parasites in a cubic inch of muscle, and by repeated feedings they succeeded in rearing about 100,000 Trichinæ in the body of a rat.
In regard to the disease in man let us glance at the phenomena that presented themselves in Plauen, a town of Central Saxony. Drs Böhler and Königsdörffer, who first saw this disease and treated it, state, according to Leuckart, that “the affection began with a sense of prostration, attended with extreme painfulness of the limbs, and, after these symptoms had lasted several days, an enormous swelling of the face very suddenly supervened. The pain occasioned by this swelling and the fever troubled the patients night and day. In serious cases the patients could not voluntarily extend their limbs, nor at any time without pain. They lay mostly with their arms and legs half bent—heavily, as it were, and almost motionless, like a log. Afterwards, in the more serious cases, during the second and third week, an extremely painful and general swelling of the body took place; yet, although the fifth part of all the patients were numbered amongst the serious cases, only one died.”
Satisfactory as it may be to note the numerous recoveries which take place, this circumstance is very much marred by the fact that a large proportion of the patients suffer the most excruciating agony. In the main it will be observed that Böhler’s and Königsdörffer’s experience, as recorded by Leuckart, corresponds very closely with that given by other observers. The symptoms, moreover, are very similar to those produced in the original case published by Zenker. In this case, which occurred in the Dresden Hospital (1860), the patient was a servant girl, aged twenty, and the principal symptoms were loss of appetite, prostration, violent pains, contraction of the limbs, and finally œdema, which, in association, perhaps, with a certain amount of pneumonia, terminated her career within a period of thirty days. The post-mortem appearances showed that the larval Trichinæ were the cause of death. The intestinal canal contained numerous sexually-mature worms.
The effects produced by Trichinæ on animals are similar to those occasioned in man. The phenomena were summarised by Davaine (in the journals quoted below) in 1863 as follows:
“The first phase is characterised by intestinal disorder, produced by the development of the larvæ in large numbers, and their adhesion to the mucous membrane of the intestine. In this stage M. Davaine has seen rabbits die with intense diarrhœa; one of two cats which he fed with trichinised meat had diarrhœa for at least a fortnight, but survived. Of five or six rats fed on a similar diet, one only, which was pregnant, died of diarrhœa, after abortion, on the eighth day. According to M. Leuckart, the passage of the embryos of Trichinæ through the intestinal walls sometimes produces peritonitis. This intestinal phase often becomes blended with the next; it may be relieved by the expulsion of the worms by means of the diarrhœa, or may cease with the natural death of the worms.
“The second stage presents general symptoms—muscular pains, &c. These phenomena are dependent on the introduction of the Trichinæ into the muscles; they rapidly acquire their maximum intensity, and have not a long duration. The appearance and duration of this stage are in complete relation with the development and length of sojourn of the Trichinæ in the intestines; in fact, in this entozoon, oviposition is not slow and of long duration, as in many nematoid worms; the genital tube is rapidly formed, and the ova, in its whole length, are developed almost simultaneously, so that the embryos, arriving soon at maturity, are at once thrown out in large numbers into the intestine, and the mother Trichina dies exhausted. If it be remembered that the embryos do not escape before the eighth day, that a certain number of days are required for their arrival in the muscles, and that new ones are not produced after six or seven weeks, it will be understood that the first symptoms of this stage can scarcely appear until the end of a fortnight after ingestion of the diseased food, that they must continue four or five weeks, and that after this they may disappear. This course of events is observed in animals; and in man the symptoms of this stage have shown themselves and become aggravated from the third to the sixth week after infection. Most animals die during this stage; rabbits rarely survive; rats, on the contrary, generally resist it.
“If the animals do not die of the general symptoms or local disturbances proper to these two stages, the inflammatory symptoms cease, respiration becomes natural, and order is re-established. But, in some cases, the number of cysts formed in the muscles are sufficiently great to impede them in the proper exercise of their functions, and hence arises general debility, a kind of consumption which persists or becomes aggravated, and the animal dies of marasmus. M. Davaine has noticed this in rabbits, but especially in a rat.
“Recovery from these phases of trichinal infection may be apparently perfect. A rabbit which M. Davaine kept during five months became large and fat, although it had a large number of Trichinæ in its muscles; a rat which had had these entozoa in considerable numbers during six months was, to all appearance, in good health. Hence he concludes that the Trichinæ produce symptoms only when they are in the intestinal canal, and when they are entering the muscles. Having become lodged in their cysts among the muscular fibres, they may remain harmless for an indefinite time. In every case except one, down to 1859, Trichinæ have been found in the bodies of persons who have died of disease (generally chronic) or by accident; or in the dissecting-room, in bodies regarding which the previous history could not be obtained. In most cases the cysts contained a cretaceous or fatty deposit, showing that they had probably existed several years.
“The observations which have been made on the human subject, in regard to the symptoms caused by Trichinæ, show that they belong, as in animals, to the initial period of infection. They consist in intestinal and in muscular lesions; the latter coincide with the entrance of the parasite into the muscles, and are truly traumatic. In Zenker’s case the intestinal symptoms were swelling and pain; in a case described by Friedreich diarrhœa was present. In all cases the most remarkable symptoms were violent rheumatoid pains in the muscles, not in the joints, which were considerably aggravated by attempts to extend the half-bent limbs. The other symptoms have been variable, but have had a strong resemblance to those of typhoid fever. In several cases there has been abundant sweating; and in one there was a very remarkable miliary and furuncular eruption. The animal heat was diminished in Friedreich’s case; and in those observed in Voigtland by Freytag the temperature never exceeded 102° Fahr.
“The progress, duration, and severity of the disease in man are in relation to the number of Trichinæ taken into the digestive canal. Of sixteen patients observed at Plauen by Drs Böhler and Königsdörffer, eight, who were moderately affected, recovered in a month; four, more severely diseased, were ill two months; of four others, one died with ascites and colliquative diarrhœa at the end of two months, and three recovered slowly at the end of three or four months. Recovery does not imply the death of the Trichinæ, it follows their enclosure in cysts.
“The diagnosis of trichinal infection has several times been made in the living human subject by removing a portion of muscle. M. Davaine thinks it probable that, during the first six or eight weeks of the disease, the diagnosis may be confirmed by searching for adult Trichinæ in the alvine evacuations, produced naturally or by means of a purgative.
“The prophylactic treatment consists simply in the avoidance of uncooked meat. The medicinal treatment must vary with the stage of the disease. At first, attempts must be made to expel the parasites from the intestines by purgatives and anthelmintics. Which amongst the latter is the most energetic is not yet determined. Calomel is, perhaps, M. Davaine thinks, the best. After six or eight weeks all treatment directed towards the intestines is superfluous. It is scarcely probable that any substance will act on the larvæ disseminated through the muscles. Friedreich has recommended picronitrate of potash; but, in the case in which he used it, live Trichinæ were found in the muscular tissue after the patient was considered to be cured.”
In regard to the possibility of curing trichiniasis by the administration of drugs which should act as trichinacides upon the parasites in the condition of flesh-worms, the absurdity of the proposal only equals that which was made in reference to the destruction of hydatids by the administration of kamala. As has been shown in the record of my first experiment the flesh of a trichinised corpse may be thoroughly saturated with a strong solution of chloride of zinc, and yet the worms will remain quite unaffected.
In reference to the dangers arising from the consumption of diseased meat, Professor Gamgee has very cogently put two questions:—“Did Moses know more about pigs than we do?” “Was it a knowledge of the parasitic diseases of swine and man that led Moses to condemn pork as human food?” Mr Gamgee answered both questions negatively, thus:—“The wisdom of the Mosaic law can only be justly estimated with a knowledge of the accidents arising in warm countries from eating pork throughout long and hot periods of the year; and there is no doubt that the direct evil results, as manifested by human sickness, led to the exclusion of pork from the list of Israelitish viands. The masses of measly pork which may be seen hanging from the butchers’ stalls in Southern Europe prove that the long-legged swine which hunt the forests for acorns, and rove about to pick up all kinds of offal, are often unfit for human food, and that they were so to no less extent in the land of Israel is probable.” As supplementing Professor Gamgee’s argument, I may remark that, if Moses had been furnished with special knowledge beyond that of his contemporaries, he would not, in the matter of meat-parasitism, have confined his restrictions to pork. Had he possessed any knowledge of measly beef, he would not have spared the ox on the ground that although “it divideth the hoof, yet it cheweth the cud.” As regards home-reared animals, Professor Gamgee cogently remarked: “It is interesting to observe that parasitic maladies in the pig specially abound in that section of the United Kingdom where swine live most amongst human beings. The Yorkshire and Berkshire pigs, in their native counties enclosed in the farmyards of their breeders, are free from worms which are likely to live in the body of man. The Irish pig is the one most commonly injured by entozoa, and the reason for this is evident when we know how much the cottager relies on rearing a porker which is permitted the free range of house and road, where every description of filth is devoured, charged with the ova of parasites expelled by man or some of the lower animals.” He also adds: “The conditions under which we live in the British isles are certainly much less favorable to the propagation of worms; but we disregard, in our ignorance, the most common precautions to protect ourselves from loathsome diseases, and not only permit dogs to eat any kind of offal in and around slaughterhouses, but sanction the existence of piggeries where all kinds of garbage, charged with worms or their eggs, are daily devoured by swine. The majority of germs calculated to engender parasites are to be found in abundance in the contents of the alimentary canal of human beings and domestic quadrupeds. If pigs are permitted to eat these, as in Ireland or in many British piggeries, we must expect hams, bacon, and pork sausages to be charged with the embryonic forms of human entozoa. Whereas in Iceland the dog is the victim of human negligence, and en revanche the cause of human disease, in the British isles the pig holds this unenviable position. We have good reason to believe, with Moses, that the pig is an unclean beast; but without discarding him from the scanty list of animals to be eaten, it is evident that we can purify the race of swine, and thus prevent human as well as porcine maladies.”
On the authority of Rupprecht, as quoted by Davaine, I append a list of the principal epidemics observed in Germany during the first six years immediately following the discovery of trichinosis:
1. Two slight epidemics in 1860 in the Island of Rügen; 10 to 20 patients (Dr Landois).
2. An epidemic at Stolberg, 1860 (Dr Fricinus). The number of trichinised persons was not stated with certainty.
3. Five epidemics during five summers, 1858 to 1862, at Magdebourg. The number of patients was 300, two only died (Dr Sendler).
4. An epidemic at Plauen in 1862, 20 patients (Böhler).
5. Gusten, 1861, 40 cases, all cured (Fränkel).
6. Epidemic in the Province of Armsted (Mansfeld), 1861, 8 patients.
7. Hettstädt, January and March, 1862, 8 to 10 patients.
8. Blankenburg, 1862, 278 cases, 2 deaths.
9. Calbe (Prussia), 1862, 38 cases (9 men, 25 women, 4 children), 8 deaths (Dr Simon and Dr Herbst).
10. Burg, in Magdebourg, 1863, 50 patients, 10 deaths (Dr Klusemann).
11. Quedlinburg, 1863, 9 patients, 1 death (Dr Behrens).
12. Plauen, 1863, 21 patients (Königsdörffer).
13. Falkenstein, 1863, 4 patients (Drs Bascher and Pinter).
14. Posen, August and September, 1863, 37 patients (Dr Samter).
15. Hamburg, 1863, 2 patients (Dr Tüngel).
16. Blankenburg, 1863, 32 patients, 2 deaths; new cases in 1864 (Dr Scholz).
17. Hettstädt (Prussian-Saxony), October, 1863, 158 patients, 27 deaths (Rupprecht).
18. Eisleben, December, 1863, and January, 1864, 18 cases, no deaths. This result was attributed to the employment of phosphoric acid (Rupprecht).
19. Hettstädt, February and March, 1864, 8 patients, no deaths. Two cats were also attacked, one of which died. Nearly 50,000 Trichina were counted in an infected leg of pork (Rupprecht).
20. Quedlinburg, 1864, 120 patients, 2 deaths; benzine was employed (Dr Wolf).
21. Hettstädt, January, 1865, 15 patients (Rupprecht).
22. Berlin, 1864, 3 cases (Dr Cronfeld). Several butcher boys (Frischer).
23. Leipzig, 1864, 14 patients, 2 deaths; 4 were infested after having eaten raw beef hashed on a block which had previously received the flesh of a trichinised hog (Dr E. Wagner).
24. Potsdam, 1864, 5 slight cases (Dr Mollendorf).
25. Celle (Hanover), 1864, 8 patients (Dr Scheller and Dr Baring); Trichina proven in the pork by Gerlach. In 1855, 12 Trichina (?) patients were treated by Schuchart.
26. Hedersleben, 25th October, 1865, a pig was killed and sold; on the 28th the malady appeared amongst the workmen; 350 patients, 100 deaths. Of 100 children infected, none died. Trichina found in the autopsies (Dr F. Kratz).
Dr Davaine also adds the following outbreaks:
In Massachusetts, 1867, 6 patients from having eaten raw ham, 1 death (‘Medical Times,’ 20th April, 1867, p. 431).
Ravecchia (Bellinzona), 1868, 5 patients, 4 deaths (Dr Zangger in Landbote of Winterthur).
Up to a comparatively recent date no case of trichinosis had been recognised in England during the life of the victim. As regards diagnosis, what was happening every day on the Continent was utterly unknown here. Whilst, however, not a single instance of Trichina-disease had been observed by British physicians in actual practice, as many as thirty or forty instances had occurred where the parasites in question had been found post mortem. I had myself examined the trichinised flesh taken from a dozen of these corpses, but in no instance had the faintest suspicion of trichinosis been entertained during life. The circumstances attending the only outbreak of trichiniasis that has been witnessed in England are very interesting. In the month of April, 1871, I received from Dr W. L. Dickinson, of Workington, Cumberland, specimens of pork which he requested me to examine; and in complying with his request I confirmed his opinion that the diseased meat was infested with Trichinæ. A few days afterwards I announced the discovery in the pages of the ‘British Medical Journal’ for April 22, p. 435. It happened, also, that at the time I was delivering a course of lectures before the Society of Arts; consequently, in my second discourse (which was devoted to the parasites of cattle) I gave full details of the facts that were obtained. Taking a small portion of the flesh which I judged to be affected to an average extent I addressed the audience as follows:
“If you calculate from one portion only, you might, if you had stumbled upon a part which was more infested with parasites than another, be led to over-estimate the degree of trichinisation. Taking proper precautions I have calculated that one scruple of this trichinous flesh would give us 4320 parasites, and two scruples would therefore yield 8640. Without speaking so precisely to numbers, I do not hesitate to aver my belief that there are at least 5000 of these parasites inside this small piece of ham. The number is probably close upon 8640. In one drachm that would give us 12,000, and in an ounce 103,000, according to the old apothecaries’ weight. If, however, we calculate according to the ordinary weight used by butchers, we should say that one ounce contains 43712 grains of meat, and therefore the number of parasites in one ounce would be 85,000. Thus, in one ounce of meat from this particular pig you have 85,000 Trichinæ, calculated at the rate of 200 in the grain, for I have purposely cut off the odd numbers. You may say, if a person can survive 18, 20, 30, or 40 millions, he would not take much harm from eating a piece of flesh containing only 8640 parasites. Such a portion, however, would be quite sufficient to make any one of us extremely uncomfortable were we to eat it, for supposing its contained parasites to be alive, it might prove dangerous to life. Why? The explanation is this:—Half of those 85,000 parasites, at the very least, will, in forty-eight hours after ingestion, have become fully-developed females; and from each of these 42,000 there will proceed at least 1000 as a brood, so that the entire progeny (and it is they that do the mischief by their independent migrations through our tissues) will eventually yield about 42,000,000 entozoa. If we should be so voracious as to eat a pound of such trichinised flesh, then there would be 400,000,000 as the result of a single meal.
“Having detailed these facts and inferences, I now wish to bring to your notice some other particulars connected with the Cumberland outbreak.
“Dr Dickinson, of Workington, tells me that he was at first suspicious that his patients were suffering from fever, but was not quite able to make out what the disorder was. At length certain symptoms occurred, which suggested that it might possibly be the German flesh-worm epidemic making its appearance in this country for the first time, and, therefore, in view of verifying the facts of the case, he sent me portions of the flesh of the pig. He describes the symptoms, which in their character corresponded with those previously recorded as experienced by persons similarly attacked. Dr Dickinson remarks, towards the close of his communication, that the victims form a small family who have carefully reared their own swine. The British farmer is thus here introduced to us at his own table playing the part of ‘host’—at her own table, I should say, for, to be more precise, it is a widow, her daughter, and a man-servant who are suffering. Dr Dickinson informs me that for two or three weeks before he was called to see them they had been eating sausages and boiled pork from one of their own home-fed pigs, which pig, by the way, turns out to have been an old sow. He brought away some sections of the leaner portions of the flesh for microscopic examination. You will observe that there can be no mistake about the source of the food on this occasion. Hitherto, Trichina has not been observed in our British-fed swine in more than one or two, or possibly three instances. Therefore it would be very interesting to ascertain how it happened that this poor pig became trichinised. In my communication addressed to the ‘British Medical Journal,’ I wrote as follows:—“Dr Dickinson has at the present time under his care a family suffering from the so-called flesh-worm disease, resulting from the consumption of ham prepared from pigs reared by the family themselves. A portion of ham sent to me swarmed with recently encapsuled Trichinæ. Dr Dickinson being thus the first person who has diagnosed trichiniasis in the living subject in England, I hope he may be induced to give us further particulars.” The editor, in commenting upon this letter, added a practical point, which I wish especially to bring to your notice. He says:—‘The subject of parasitic diseases of domestic animals is one of widespread and increasing interest. It is immediately related to the irrigation of fields with sewage.’ The editor, of course, made this statement on independent grounds, and on his own responsibility. If he had said the subject bears an indirect relation to the sewage question, he would have said no more than is absolutely true, for, as I shall take occasion to explain, there is every reason to suppose that certain forms of parasitic disease may be propagated by means of sewage. In this connection some of you may be disposed to ask the question:—‘Are there any sources of comfort to be gathered from the facts?’ Or you may say, supposing that in future our British swine are not as free from Trichinæ as they have been hitherto, can we possibly avoid the contingency of playing the part of host to those creatures? Certainly, I reply, it is simply a question of properly cooking the food. If these farmers have not cooked their food at all, or scarcely at all, that will at once account for their being laid up. I should tell you that the lady and the daughter are recovering, and that they are convalescent, but the man-servant is very ill. If, during cooking, the flesh consumed by these persons had been raised to a persistent temperature of 170° Fahr., then, doubtless, the ingestion of trichinised pork would have done no harm. You observe that Dr Dickinson says in his letter that they partook of it roasted and boiled. Now, few of us are in the habit of eating underdone pork, although there are other meats that we devour very readily in an imperfectly cooked state. It must be remembered, also, that although the exterior may have been subjected to a temperature of 212 degrees, it by no means follows that the whole of the joint throughout must have been submitted to that temperature. Under rapid cooking, the centre of a large joint may remain much below even 140 degrees. If the man-servant ate only one ounce of the flesh with living Trichinæ in it, he will probably have at this present moment at least 42,000,000 of these guests in his muscles. You will ask, ‘Will he recover?’ ‘Yes; if he ate no more than that.’ If he has eaten 2 oz. thoroughly underdone, depend upon it he has 80,000,000, and if he has eaten 3 oz. he will have over 100,000,000 of Trichinæ in his muscles. Could he survive if he had eaten over 3 oz., and thus have 100,000,000 and upwards of these inhabitants? I think he could. We have evidence on this point from the case in which I estimated that there were upwards of 100,000,000 of Trichinæ present, and yet the man survived the attack.
“Incidentally I may remark that in the course of the last twenty years, although millions of parasites and their eggs have passed through my hands, I have almost entirely escaped infection. It is something to know what you are either handling or looking at, because there are many parasites besides Trichina which are dangerous. There are gregariniform entozoa residing in meat which we eat every day without any bad consequences. They are as harmless as cheese-mites. There is no need to be in the slightest degree nervous about flesh-food, provided it is properly cooked. I believe there will be no fatal issue in the case of any of the three individuals just alluded to, but the chief practical point before us arises out of the fact that we have here, for the first time in England, an epidemic of trichiniasis. By calling attention to the subject, it will, to say the least, suggest precautions by which future epidemics may be avoided.”
The above remarks form the substance of a lecture given on the 24th of April, 1871. A week later I delivered the third of the Cantor lectures for that year, when I took occasion to add the following particulars:
“It has been asked whether the so-called muscle-Trichinæ, after they have arrived at their destination within the flesh of man, are capable of producing any more unfavorable consequences? The answer is, Certainly not. In the case of man it would be necessary that his muscles should be eaten in order for the Trichinæ to become sexually-mature worms; and in those countries where cannibalism exists, the man-eater would himself become trichinised, and would certainly deserve his fate. I was very desirous to follow up the account of this outbreak by inquiries respecting the particular animal which had been the cause of the outbreak. I may therefore mention that my informant, Dr Dickinson, states that the family, including the man-servant, all fed together, and that they had for upwards of a fortnight eaten daily, and sometimes twice a day, sausages made from the flesh of the trichinised animal. And he adds: The meat cut from the ham and flitches, and what is called the spare-rib, was roasted before the fire or in the frying-pan. Occasionally it was cooked in the oven. Dr Dickinson ascertained from the mother that she liked her meat to be underdone, and thus, therefore, there is very little doubt that the meat was generally undercooked. The man, a strong labourer, had a good appetite, and would therefore get a large share. He is improving slowly. Dr Dickinson adds in a postscript, what is still more to the point, that the sausages would be most likely undercooked; they would be cooked in the frying-pan, and if only brown on the outside would be eaten. It is probable that the outbreak was due therefore to eating underdone meat from this pig, cooked in various ways, and not alone from the ham itself.”
If the facts connected with this outbreak be honestly faced, it must be rendered clear to any unprejudiced observer that Dr W. Lindow Dickinson was the first person to observe, recognise, and treat the Trichina disorder in this country. No other English, Scotch, or Irish physician has encountered any similar case. If I lay stress upon this fact it is because I have learned from Dr Dickinson that another person has asserted priority in this relation. Sir Dominic Corrigan is stated to have told a gentleman in the House of Commons, “that he had often met with trichiniasis in his practice in Dublin,” further averring that the disease “was quite common in many parts of Ireland.” If Sir D. Corrigan merely desired it to be understood that he had repeatedly encountered the Trichina at post-mortem examinations, then there is nothing surprising in his statement, but if, on the other hand, the disease itself has been frequently recognised in the living Irish human subject, one can only express astonishment that hitherto no single instance of the kind appears to have been recorded either in the public or professional journals.
Bibliography (No. 21).—English Literature.—Allman, G. J., “Exhib. of Specimens,” ‘Micr. Jrn. and Structural Record,’ 1842, p. 94.—Althaus, J., ‘Essay on Trichinosis,’ London, 1864.—Idem, “On a Suspected Case,” ‘Med. Times and Gaz.,’ 1864, p. 161; see also pp. 362 and 390.—Atwood, see Belfield.—Ballard, E., “On Diseased Meat,” ‘Med. Times and Gaz.,’ 1864.—Belfield (with Atwood), “Trichinæ in Pork;” ‘New York Med. Rec.,’ Dec. 28, 1878; ‘Med. Times and Gaz.,’ Feb. 15, and ‘Lancet,’ Feb. 22, 1879.—Bellingham, O. B., ‘Dublin Med. Press,’ 1852.—Bowditch, H. J., “Cases of Trichina,” ‘Boston Med. and Surg. Journ.,’ 1842–43–44.—Bristowe, J. S. (and Rainey), ‘Trans. Path. Soc.,’ 1854.—Chevers, N., “Sanitary Efforts in regard to Trichiniasis,” ‘Lancet,’ 1864, vol. ii, p. 733.—Cobbold, T. S., “On the Discovery of Trichina, in relation to the question of Priority,” ‘Lancet’ for March 3, 1866, p. 244.—Idem, ‘Parasites, and the part they play in the Economy of Nature’ (lecture), Manchester, 1873, p. 46; also in the ‘Veterinarian,’ March, 1874.—Idem, Remarks in the ‘Journ. Soc. of Arts,’ 1866, p. 399; also in ‘Med. Times. and Gaz.,’ 1867, p. 24; also in ‘Lancet,’ Feb., 1864 and 1866, p. 538.—Idem, ‘Our Food-producing Ruminants and the Parasites which reside in them’ (Cantor Lectures), 1871.—Idem, “Experiments with Trichina,” ‘Proceed. Linn. Soc.,’ vol. ix, p. 205, 1867; see ‘Lancet’ for Jan. 13, 1866, p. 52; ‘Brit. Med. Journ.’ for Dec. 22, 1866, p. 713; also ‘Lancet’ for Jan. 9, 1867, p. 91.—Idem, “Worms” (l. c., Bibliog. No. 2, Lecture xviii), 1872.—Idem, “Outbreak of Trichinosis in England,” ‘Brit. Med. Journ.,’ 1871, p. 435.—Idem, “Trichinæ in Fish” (alleged to have been found in a pike by Dr Elendenen at Ostend), in the ‘Lancet’ (anonymous annotation) for Nov. 16, 1878.—Curling, T. B., two cases, ‘Lond. Med. Gaz.,’ 1836.—Davaine, C., quoted in ‘Brit. Med. Journ.,’ see foreign lit., below.—Delpech, abstr. of his Report, ‘Brit. Med. Journ.,’ 1866, p. 375.—Dickinson, W. L., ‘Brit. Med. Journ.,’ 1871.—Elendenen, “Trichinæ in Fish” (newspaper report respecting his “find”); see Cobbold, above.—Farre, A., “Observations,” ‘Lond. Med. Gaz.,’ 1835–36.—Friedreich, N. (trans. by Ogle), ‘Med.-Chir. Rev.,’ 1863, repr. in ‘Edin. Vet. Rev.,’ 1863.—Furstenburg, ‘Edin. Vet. Rev.,’ 1864, p. 513.—Gordon (see Chevers).—Gamgee, J., “On Diseased Meat,” ‘Pop. Sci. Rev.,’ 1864.—Goodsir, J., ‘Month. Journ. Med. Sci.,’ 1842.—Harr, ‘Bost. Med. and Surg. Journ.,’ 1866, p. 532.—Harrison, “On a peculiar Species of Entozoon occasionally found in the Voluntary Muscles of the Human Subject,” ‘Rep. of Brit. Assoc.,’ Aug. 12, 1835; in ‘Dub. Journ.,’ vol. viii, 1835–36; in ‘Lond. and Edin. Phil. Mag.,’ and in ‘Amer. Journ. Med. Sci.,’ vol. xviii, p. 187, 1836.—Herbst, “Trichinæ in the Badger,” ‘Assoc. Med. Journ.,’ 1853, p. 491.—Hilton, J., “Notes on a peculiar appearance observed in Human Muscle, probably depending upon the formation of very small Cysticerci,” ‘Lond. Med. Gaz.,’ vol. xi, p. 605, 1833.—Jackson, J. D., “Trichiniasis,” in ‘Hay’s Amer. Journ.,’ 1867, p. 82.—Kiefer, H., cases, ‘Bost. Med. and Surg. Journ.,’ 1866, p. 208.—Kobelt, ‘Micr. Journ. and Struct. Rec.,’ 1842, p. 147.—Kratz, “On the Hedersleben Epidemic,” ‘Brit. Med. Journ.,’ 1866, p. 76.—Krombein, “Trichiniasis in New York,” ‘Amer. Journ. Med. Sci.,’ 1864, and ‘Med. Times and Gaz.,’ 1864, p. 292.—Küchenmeister, F., Symptoms, &c., ‘Lond. Med. Rev.,’ 1860, p. 457.—Langenbeck, case, ‘Edin. Vet. Rev.,’ Feb., 1864.—Leidy, J., “Trichina in the Pig,” ‘Annals of Nat. Hist.,’ and ‘Pr. Ac. N. S. Philad.,’ 1847.—Leuckart, R. (translations from), in ‘Ann. Nat. Hist.,’ 1860; in ‘Qrt. Journ. Micr. Sci.,’ 1860; and in ‘Bost. Med. and Surg. Journ.,’ vol. liii, p. 198, 1860–61.—Liveing, R., “Path. Soc. Rep.” in ‘Med. Times and Gaz.,’ 1865, p. 374.—Mosler, “On Trichinous Flesh,” ‘Brit. Med. Journ.,’ 1864, p. 554.—Idem, “On Benzine in Trichinosis,” ‘Med. Times and Gaz.,’ Oct., 1864, p. 444.—Nunneley, T., ‘Brit. Med. Journ.,’ 1866, p. 252.—Owen, R., “Description of a Microscopic Entozoon infesting the Muscles of the Human Body,” ‘Proc. Zool. Soc.,’ and ‘Lond. Med. Gaz.,’ 1835; ‘Trans. Zool. Soc.,’ vol. i, 1835.—Idem, Remarks in ‘Journ. Soc. of Arts,’ 1866, p. 399.—Paget, J., “Letter relating to the Discovery of Trichina,” ‘Lancet,’ March, 1866, p. 269.—Rorie, J., Letter, ‘Lancet,’ Feb., 1864.—Salisbury, J. H., On a supposed Species of Trichina (T. cystica) from the Human Bladder; in his paper on “Parasitic Forms,” in ‘Hay’s Amer. Journ. Med. Sci.,’ 1868, p. 376.—Sanders, R., ‘Edin. Month. Journ.,’ 1853.—Sawer, A., ‘Bost. Med. and Surg. Journ.,’ 1865, p. 16.—Sutton, G., Report on Trichinosis; Indiana, U.S., 1874.—Thudichum, J. W. S., ‘Brit. Med. Journ.,’ Jan., 1864, repr. in ‘Glasgow Med. Journ.,’ April, 1864, p. 116; also letter in ‘Edin. Med. Journ.,’ Feb., 1864.—Idem, “Rep. on the Parasitic Diseases of Quadrupeds used as Food,” pub. by the Med. Officer of the Privy Council, London, 1865.—Idem, “The Diseases of Meat as affecting the Health of the People,” ‘Journ. Soc. of Arts,’ April 20, 1866.—Idem, “German Sausages and the Trichina Disease,” ‘Scientific Opinion’ for April 25, 1866.—Idem, ‘Lancet’ for Jan. 6, 1866, p. 16.—Turner, W., “On the Trichina spiralis,” ‘Edin. Med. Journ.,’ Sept., 1860; in the ‘Year-Book,’ p. 109, for 1860; in ‘Med.-Chir. Rev.,’ 1862; and in ‘Bost. M. and S. Journ.,’ vol. lxiii, p. 294.—Ude, “Rep. on the Inspection of Pigs,” ‘Med. Times and Gaz.,’ Aug., 1868, p. 141.—Valentin, ‘Micr. Journ. and Struct. Rec.,’ 1842, p. 87.—Virchow, R., Extr. from his brochure on ‘Trichina’ (by myself), in ‘Gunther’s Record’ for 1864, p. 611.—Idem, “On the Cure of Trichinosis,” ‘Brit. Med. Journ.,’ April, 1866, p. 368.—Idem, from “Comptes Rendus,” in ‘Qrt. Journ. Micr. Sci.,’ 1861.—Idem, from his ‘Archiv,’ 1860, Bd. xviii, Heft. 4, p. 330; in ‘Brit. and For. Med.-Chir. Rev.,’ vol. xxvi, p. 515, 1860.—Wedl, Report, ‘Brit. Med. Journ.,’ Dec., 1866, p. 618.—Wilks, S., “Letter respecting the Discovery of Trichina,” ‘Lancet,’ March 10, 1866, p. 269; see also the ‘Times,’ Feb. 13, 1866.—Windsor, J., ‘Brit. Med. Journ.,’ March 4, 1866, p. 319.—Wood, H., case, ‘Lond. Med. Gaz.,’ 1835.
Foreign Literature:—Ardenghi, E., “Sulla Trichina spiralis,” ‘Lo Studente Veterinario,’ 1876, p. 115.—Behrens, “Ein Fall von Trichiniasis,” ‘Deutsche Klinik,’ No. 30, 1863 (quoted by Davaine).—Bette, F., ibid., 1876.—Bischoff, ‘Path. Anat. des menschl. Körp.,’ 1845.—Idem, ‘Med. Annalen,’ 1840.—Böhler, ‘Die Trichinenkrankheit in Planen,’ 1863.—Boudin, “Des épidémies de Trichina spiralis observées en Allemagne dans ces dernières années,” ‘Journ. de Méd. Vét. Milit.,’ August and September, 1864 (quoted by Davaine).—Claus, ‘Wurzb. nat. Zeitschr.,’ 1860.—Idem, ‘Ueber die Trichine’ (a discourse), 1877.—Colberg, ‘Deutsche Klinik,’ 1864.—Davaine, C., ‘Traité’ (l. c., Bibl. No. 1), 1860, p. 672, 2nd edit., p 732–768.—Idem, “Faits et Considerations sur la Trichine,” ‘Mémoires de la Société de Biologie’ for the year 1862, tom. iv, ser. 3, 1863; in ‘Gazette Médicale de Paris,’ 1863; in ‘British Medical Journal’ for April 25, 1863; and in my ‘Entozoa,’ p. 349.—Idem, “La Trichine” (popular exposition), in ‘Revue des Deux Mondes’ for May, 1865.—Dujardin (l. c., Bibl. No. 1), p. 24.—Fiedler, ‘Virchow’s Archiv,’ 1864.—Fleckles, F., ‘Die Trichinen und die Trichinenkrankheit’ (popular exposition), Prag., 1866 (quoted by Davaine).—Friedrich, N., ‘Virchow’s Archiv,’ 1862.—Fürstenberg, “Wochenblatt d. Ann. der Landwirthsch., in d. Königl. Preuss. Staaten,” 1865.—Gerlach, C., ‘Die Trichinen,’ 1866.—Idem, ‘Hannöversche Zeitschrift,’ 1864.—Hagen, in ‘Pharmaceutische Centralhalle,’ 1862.—Henle, ‘Muller’s Archiv,’ 1835, s. 526.—Herbst, ‘Nachrichten v. d. Georg-Aug. Univ. zu Göttingen,’ 1852; ‘L’Institut,’ 1852, p. 135.—Heschl, R. L., ‘Ueber Trichinen, die Trichinenkrankheit und die Schützmassregeln dagegen,’ Gratz, 1866 (quoted by Davaine).—Kestner, “Etude sur le Trichina,” ‘Gaz. Méd. de Paris,’ 1864.—Klusemann, “Die Erkrankung durch den Genuss von Nahrungsmittel aus dem Thierreiche,” ‘Deutsche Klinik,’ 1864.—Kobelt, ‘Valentin’s Repertorium,’ 1841.—Krabbe, “Husdyrenes Indvoldsorme,” ‘Tiddsskrift for Vet.,’ 1872.—Kratz, ‘Die Trichinenepidemie zu Hedersleben,’ 1866.—Küchenmeister, ‘Parasiten,’ 1855.—Leuckart, ‘Untersuchungen ueber Trichina spiralis,’ 1866.—Idem, ‘Die mensch. Par.,’ Bd. ii, s. 409.—Idem, “Die neuesten Entdeckungen ueber menschliche Eingeweidewürmer und deren Bedeutung für die Gesundheitspflege,” ‘Unsere Zeit.,’ 1862.—Lion, ‘Zur Geschichte, Therapie, Prophylaxis, und Sanitätspolizei der Trichinen’ (quoted by Pagenstecher).—Luschka, “Zur Naturgeschichte der Trichina spiralis,” ‘Zeitschr. für wissenschaftl. Zool.,’ 1851.—Meissner, ‘Zeitschr. f. rat. Med.,’ 1855.—Idem, “Ueber Trichinenkrankheit,” ‘Schmidt’s Jahrbücher,’ 1863.—Ordonez, E. L., ‘Note sur la Distinction des Sexes et le Développement de la Trichina spiralis des Muscles,’ Paris, 1863; and ‘Compt. Rend. Soc. Biologie,’ p. 61, 1863 (quoted by Davaine).—Pagenstecher, ‘Verhandl. d. Naturhist.-Med. Vereins zu Heidelberg,’ 1864.—Idem (und Fuchs), ‘Die Trichinen,’ 1865.—Perroncito, “La Trichina spiralis” in ‘Italia. Estr. degli Annali R. Accad. d’Agric. di Torino,’ vol. xx, 1877.—Reyher, O., ‘Die Trichinenkrankheit,’ Leipzig, 1862.—Rodet, H., ‘De la Trichine et de la Trichinose,’ Paris, 1865 (quoted by Davaine).—Rupprecht, B., ‘Die Trichinenkrankheit im Spiegel der Hettstedter Endemie betrachtet,’ Hettstedt, 1864.—Seidel, ‘Jenaische Zeitschr. f. Med. u. Nat.’ 1864.—Siebert, ‘Ueber die Trichinenkrankheit und ihre Vermeidung,’ Jena, 1863.—Siebold, art. “Parasiten,” ‘Wagner’s Handwörterbuch,’ 1844.—Simon, G., “Eine Trichinen-epidemic in Calbe,” ‘Preussische Medicinal Zeitung,’ 1862.—Tommasi, ‘La Trichina spiralis e la Malattia prodotta da esso,’ Torino, 1863.—Tüngel, ‘Archiv von Virchow,’ xxvii, 3, 421, 1863 (quoted by Davaine).—Virchow, ‘Deutsche Klinik,’ 1859; ‘Comptes Rendus de l’Acad. des Sci.,’ tom. xlix.—Idem, ‘Archiv f. Path. Anat. und Physiol.,’ Bd. xviii.—Idem, ‘Darstellung der Lehre von den Trichinen’ (fur Laien und Aerzte), 1864.—Vogel, ‘Die Trichinenkrankheit,’ 1864.—Wagner, “Eine Trichinenepidemie in Leipzig,” ‘Arch. der Heilkunde,’ 1864.—Wunderlich, C. A., “Sur la diagnose probable de l’affection trichinale,” ‘Gaz. Méd. de Paris,’ p. 311, 1863; from ‘Wagner’s Archiv der Heilkunde,’ ii, 3, p. 269, Leipzig, 1861 (quoted by Davaine).—Zenker, “Zur Lehre von der Trichinenkrankheit,” ‘Deutsches Archiv. für Klin. Med.,’ Bd. viii, s. 387.—Idem, ‘Virchow’s Archiv,’ 1855 and 1860.
Trichocephalus dispar, Rudolphi.—This well-known worm possesses a long filiform neck, occupying about two thirds of the entire length of the body. The surface of the skin though smooth to the naked eye is furnished on one side with a longitudinal band of minute wart-like papillæ. The tail of the male is curved, and emits at the extremity a short, tubular penis-sheath, armed with minute retroverted spines. The tail of the female is straight and bluntly pointed. The eggs measure 1480″ to 1447″ in their long diameter. The whipworm infests the cæcum, and also the upper part of the colon. Upwards of one thousand were found by Rudolphi in a woman.
The original name of Trichuris, given to this worm by Buttner, could not, of course, be allowed to stand when it became evident that the so-called tail was in reality the head and neck. The Trichocephalus is not uncommon in England and Ireland. It is less frequent in Scotland. On the continent, however, it is so abundant that M. Davaine calculates that not less than one half of the inhabitants of Paris are infested by it. From what Dujardin has said it can be scarcely less abundant in Northern France, for M. Duval, the distinguished director of the Rennes School of Medicine, supplied that helminthologist with numerous specimens on various occasions. The worm abounds in Italy and Egypt; being scarcely less prevalent in the United States. The lamented Mr Noel, one of my old pupils at the Middlesex Hospital College, brought me specimens which he found post-mortem on three or four occasions. Dr Haldane, of Edinburgh, once or twice obtained large numbers (post-mortem). In Ireland, Bellingham found the worm in eighty-one out of ninety post-mortem examinations. Mr Cooper, of Greenwich, met with it, post-mortem, in eleven out of sixteen instances. When treating patients for tapeworm I have repeatedly expelled the whipworm.
The organisation of Trichocephalus dispar has been investigated by Dujardin, Mayer, Von Siebold, Eberth, Bastian, and others. Prof. Erasmus Wilson and myself have carefully studied the anatomy of the closely-allied whipworm of ruminants (T. affinis) which is discussed in my ‘Entozoa.’
The statement of Küchenmeister that there are no external appendages in the female Trichocephalus comparable to those known to exist in the allied Trichosomata, is incorrect. Leuckart’s, and especially Virchow’s, researches disproved Küchenmeister’s and Meissner’s notion that Trichinæ were the young of Trichocephalus. The experiments of Davaine render it probable that the young get into the human body in a direct manner. He finds that the eggs undergo no development whilst yet lodged within the host’s intestines. The eggs are expelled per anum in the immature condition in which they first escape from the body of the parent worm. It further appears that, after their expulsion, a period of six months must elapse before embryonic formation commences. The fully-developed embryo measures 1333″ in length, and resembles the parent to a certain extent.
Whipworms rarely put their bearers to inconvenience; nevertheless, both human and animal hosts occasionally suffer from their presence. Thus, Felix Pascal quotes a remarkable and fatal instance of cerebral symptoms from this cause in a girl of four years of age; and Mr Gibson has recorded an instance in which these worms produced paralysis and loss of speech. According to Professor Axe, sheep suffer severely from the allied species.
Bibliography (No. 22).—Bastian, H. C., “On the Anatomy of the Nematoids,” ‘Phil. Trans.,’ 1866, p. 545.—Bellingham, O. B., “On the frequency of Trichocephalus dispar in the Human Intestines,” ‘Rep. of Brit. Assoc., in Dubl. Journ.,’ 1838, and in ‘Med. Chir. Rev.,’ 1838; see also Bibliog. No. 33 (and the biography of Bellingham by Dr Mapother, in ‘Dubl. Jrn. Med. Sci.,’ 1877, p. 471).—Busk, G., “Anat. of T. dispar,” ‘Ann. Nat. Hist.,’ vol. vii, 1841.—Chiaje, sul Tricocephalo disparo, &c., 1836.—Cobbold, ‘Entozoa,’ pp. 69 and 329.—Idem, ‘Worms,’ pp. 31 and 67.—Davaine, l. c., p. 205.—Idem, ‘Compt. Rend.,’ 1858, p. 1217, and ‘Journ. de Physiol.,’ 1859, p. 296.—Dubini, ‘Entozoografia umana,’ p. 83.—Dujardin, l. c., p. 32.—Eberth, “Die Generationsorgane von T. dispar,” ‘Sieb. und Köll. Zeitschr.,’ 1860, s. 384.—Gibson, D., “On a Case of Paralysis, with loss of speech, from intestinal irritation (produced by T. dispar),” ‘Lancet,’ Aug. 9th, 1862, p. 139.—Goeze, ‘Naturg.,’ s. 112.—Gurlt, ‘Path. Anat.,’ p. 350.—Küchenmeister, l. c., s. 235; Eng. edit., p. 321.—Leidy, ‘Proc. Acad. Phil.,’ viii, p. 53.—Leuckart, l. c., s. 465.—Mayer, Sieb. und Köll. ‘Zeitsch. f. wiss. Zool.,’ Bd. ix, s. 367; Bd. x, s. 233, and s. 383, 1858–60.—Mérat, ‘Dict. Sc. Méd.,’ p. 560.—Von Siebold, ‘Wiegm. Arch.,’ 1845.—Wilson, E., ‘The Veterinary Record and Trans.,’ vol. ii, p. 47, 1846.
Filaria Bancrofti, Cobbold.—The history of the discovery of this entozoon is second only in interest to that of Trichina spiralis. Step by step the facts have been evolved by a slow process of observation, and from the data thus afforded a tolerably connected narrative of the probable life-cycle of this entozoon may now be offered. To place matters beyond all doubt much remains to be done; yet that which has been accomplished is, or ought to be, of surpassing interest alike to the physician, the scientific pathologist, the epidemiologist, and the philosophic naturalist. In the case of Trichina, Owen’s nomenclature was most properly allowed to stand; but for reasons stated below I have not hesitated to employ for this worm, in its adult state, a name differing from that originally given to the hæmatozoon which turns out to be its representative larval state. Although the male parasite is at present unknown, the following characters will in the meantime suffice for a diagnosis of the species:—Body capillary, smooth, uniform in thickness. Head with a simple circular mouth, destitute of papillæ. Neck narrow, about one third of the width of the body. Tail of female simple, bluntly pointed; reproductive outlet close to the head; anus immediately above the tip of the tail. Length of largest females, 312 in.; breadth, 190″; embryos, 1200″ to 1125″ in length, by 13000″ to 12250″ in breadth; eggs, averaging 11000″ by 11650″ from pole to pole.
The first discovery of this entozoon, in its embryo state, was made by Wucherer on the 4th of August, 1866. To use Dr Da Silva Lima’s words:—“At the moment when Wucherer was seeking for the Bilharzia hæmatobia, he found instead of it an unknown worm. Our illustrious collaborator,” adds Dr Lima, “has made his important discovery known under the modest title of ‘Preliminary Notice on a species of Worm at present not described;’ and still more modestly Wucherer formulated in the following manner his judicious and prudent conclusions:—It would be rash on my part to put forth a conjecture on the coexistence of these worms of the hæmatochyluria, and on the etiological signification which they might have. I shall therefore abstain until I have been able to make more ample investigations, and until I have been permitted to examine the corpse of a hæmaturic, which has not yet been possible.” (‘Gazeta Medica da Bahia,’ Dec., 1868, p. 99.)
In the year 1868 Dr J. H. Salisbury referred certain ova which he found in the urine to a new and distinct species of nematode. Although he had no acquaintance with the adult parasite, Dr Salisbury at once placed the “species” in the genus Trichina. Here is what he says:—“Trichina cystica (Salisbury).—This is a small species which I have found in the human bladder. In all my examinations I have met with this little entozoon in three cases only. In two of these it was only occasionally met with in the urine. In the other it occurred in great numbers. Frequently from ten to fifteen ova were found in a single drop of urine.”