Into purely professional questions connected with the treatment of the echinococcus malady I do not here enter; nevertheless, in connection with hygiene I may observe that the prevalence of hydatids in any country is strictly dependent upon the habits of the people. The close intimacy subsisting between the peasantry and their canine companions is the primary source of the endemic; and where dogs are not kept, it is well nigh impossible that the disease should be contracted. The fact that every Icelandic peasant possesses, on an average, six dogs, and that these dogs share the same dwelling (eating off the same plates and enjoying many other privileges of intimate relationship) sufficiently explains the frequency of hydatids in that country. According to Krabbe, the sexually mature Tæniæ occur in 28 p. c. of Icelandic dogs, whereas in Copenhagen he found it twice only in 500 dogs examined. In his work (quoted below, p. 58, or Fr. Edit., p. 60) Krabbe comments on a sensational passage which, in my introductory treatise (p. 283), I had quoted from a popular memoir by Leuckart (‘Unsere Zeit,’ s. 654, 1862). The practitioners whom we had spoken of as “quacks” are mostly homœopaths; and it appears that even those who are not in any legal sense professional men “treat their patients much in the same way as ordinary medical men.” It simply comes to this, that, instead of dog’s excrement forming with the aforesaid “quacks” a conspicuous or common remedy (as Leuckart’s description had led me to infer), this nasty drug is now rarely administered, and by the grossly ignorant only.
Up to the present time no person has seen the Tænia echinococcus in any English dog which has not been previously made the subject of experiment, but considering the prevalence of hydatid disease amongst us, there can be no doubt that English dogs are quite as much if not more infested than continental ones. Probably, at least one per cent. of our dogs harbour the mature tapeworm. Certainly a great deal of good might accrue from the acquisition of more extended evidence respecting the prevalence of this and other forms of entozoa infesting man and animals in this country.
From Schleissner’s table it appears that hydatids are more frequent in women than in men. Apparently, it is not so in Australia. As regards Iceland the explanation must be sought for in the different habits of life. No doubt, water used as drink by women is constantly obtained from supplies in the immediate neighbourhood of dwellings, and in localities to which dogs have continual access. The comparative rarity of the echinococcus disease amongst sailors is not so much dependent upon the circumstance that seamen’s diet usually consists of salted provisions, as upon the fact that these men can seldom have opportunities of procuring water from localities where dogs abound. In regard to water drinking, there is ground for believing that the addition of a very little alcohol is sufficient to destroy the six-hooked embryos of Tænia echinococcus whilst still in ovo; and there is no doubt that water raised to a temperature of 212° Fahr. will always ensure the destruction of the larvæ. Boiled water by itself is by no means palatable. The reason why the upper classes comparatively seldom suffer from hydatids may be attributed to the circumstance that those few who drink water take the very proper precaution to see that it is either “pump” or fresh spring water in which no living six-hooked embryos are likely to exist. So far as hydatids are concerned, wine and beer drinking is preferable to water-drinking; yet if water is carefully filtered no evil of the parasitic kind can possibly result from its imbibition. An ordinary charcoal filter will effectually prevent the passage of the ova, since their diameter is nearly 1/370 of an inch.
From what has been stated it follows that personal and general cleanliness are eminently serviceable as preventions against infection, but to ensure perfect success other precautions must be exercised, especially in relation to our contact with and management of dogs. Leuckart puts this very clearly when he says:—“In order to escape the dangers of infection, the dog must be watched, not only within the house, but whilst he is outside of it. He must not be allowed to visit either slaughter-houses or knackeries, and care must be taken that neither the offals nor hydatids found in such places are accessible to him. In this matter the sanitary inspector has many important duties to perform. The carelessness with which these offals have hitherto been disposed of, or even purposely given to the dog, must no longer be permitted if the welfare of the digestive organs of mankind is to be considered. What blessed results may follow from these precautions may be readily gathered from the consideration of the fact that, at the present time, almost the sixth part of all the inhabitants annually dying in Iceland fall victims to the echinococcus epidemic” (l. c., s. 654). Similar measures had previously been recommended in less explicit terms by Küchenmeister, who in effect remarked that the principal thing was to ensure the destruction of the echinococcus vesicles. He also recommended the expulsion and annihilation of the Tænia echinococcus. In order to carry out this idea, it was suggested by Dr Leared that every dog should be periodically physicked, and that all the excreta, tapeworms included, should be buried at a considerable depth in the soil. I advised, however, that in place of burying the excreta, they should, in all cases, be burnt. I had, indeed, long previously urged this measure (in a paper “on the Sclerostoma causing the gape-disease of fowls,” published in 1861), with the view of lessening the prevalence of entozoa in general, whether of man or animals. The rule I suggested stood as follows:—All entozoa which are not preserved for scientific investigation or experiment should be thoroughly destroyed by fire, when practicable, and under no circumstances whatever should they be thrown aside as harmless refuse. As an additional security I recommended that boiling hot water be occasionally thrown over the floor of all kennels where dogs are kept. In this way not only would the escaped tapeworms be effectually destroyed, but also their eggs and egg-contents, including the six-hooked embryos. These measures were again advocated at the Cambridge Meeting of the British Association in 1862, and also more fully in a paper communicated to the Zoological Society, during the autumn of the same year (‘Proceedings,’ vol. xxx, pt. 3, pp. 288, 315).
As the scope and tendency of this work preclude the textual admission of clinical details, I must limit my remaining observations to the pathology of hydatid disease. At very great labor, pursued at distant intervals during a period of ten years, I sought to ascertain the probable extent and fatality of this form of parasitism in England, by going over such evidence as our pathological museums might supply. Although, from a statistical point of view, the investigation could hardly be expected to yield any very striking results; yet clinically viewed the study was most instructive. The evidence which I thus procured of numerous slow and painful deaths from echinococcus disease, further stimulated me to place a summary of the facts on record. Physicians, surgeons, scientific pathologists, and veterinary practitioners are alike interested in the study of hydatid disease; and I had not proceeded far in my careful investigation before it became evident to me that very great practical results would ensue if, in this kind of effort, the principle of division of labor had full play. At all events, within these museums lie concealed a mass of pathological data which, although well within reach, have not been utilised to the extent they ought to have been.
As a student of parasites for some thirty years, I must without offence be permitted to protest against the too frequent omission of parasites in statistical evidence as a cause of mortality. From facts within my own knowledge I can confidently assert that parasites in general, and hydatids in particular, play a far more important part in the production of disease and death than is commonly supposed. In saying thus much, however, I am not insensible to the fact that, in recent times, new methods of treatment combined with higher surgical skill, have greatly tended to lessen the fatality of this affection. In this connection I would especially refer to the recorded experiences of an able colonial surgeon, Dr MacGillivray, as made known in the pages of the ‘Australian Medical Journal.’ The able surgeon to the Bendigo Hospital, treated as in-patients, from 1862 to 1872, inclusive, no fewer than seventy-four cases of hydatid disease. He operated on fifty-eight of them. Two patients were tapped for temporary relief (as they were dying of other diseases); and of the remaining fifty-six only eleven died. No fewer than forty-five were discharged cured—a fact redounding largely, I should think, to the credit of Australian surgery.
In reference to museum evidence I have no hesitation in saying that the pathological collections in the metropolis abound in rare and remarkable illustrations of hydatid disease; most of the preparations being practically known only to such few members of the medical profession as have been at some time or other officially connected with the museums. Not without justice, curators often complain that their work and catalogues are turned to little account. As a former conservator of the Edinburgh University Anatomical Museum (1851–56), and subsequently as museum-curator at the Middlesex Hospital Medical College, I am in a position to sympathise with them. Valuable, however, as the catalogues are, it is often necessary to make a close inspection of the preparations in order to arrive at a correct interpretation of the facts presented.
Although the entozoal preparations in the museum attached to St Bartholomew’s Hospital are, comparatively speaking, few in number, there are some choice specimens of hydatid disease. There is a remarkable case in which hydatids invaded the right half of the bones of the pelvis; death resulting from suppurative inflammation of the cysts. This patient, a woman, had also another hydatid cyst which was connected with the ovary. Amongst the series contributed by Dr Farre, there is a case represented where a large cyst containing numerous hydatids “occupied the pelvis of an infant and produced retention of urine,” which ultimately proved fatal. There are also several fine examples of hydatids from the omentum (Dr Farre’s case), besides a good specimen of acephalocysts connected with the vesiculæ seminales. There are two other cases in which these larval entozoa were passed with the urine. At the time when I made my inspection, the entire series represented twenty-five separate cases, of which only one appears to have been published in detail (Mr Evans’s case, ‘Medico-Chirurgical Transactions,’ 1832). In addition to the above, I must not omit to particularise two instructive preparations illustrative of a case in which an hydatid was lodged in the right half of the cerebrum. This was from a girl in whom head symptoms showed themselves a year before death, and in whom there was partial hemiplegia of the left side. I may add that there is also in the series a doubtfully genuine example of hydatids of the breast.
The collection in connection with the Westminster Hospital contains several highly interesting specimens of entozoa (one of which I believe to be altogether unique), but it is by no means rich in the matter of hydatids. Out of a score of preparations of parasites of various kinds, only four (apparently representing the same number of cases) are hydatids, all of which appear to have been connected with the liver. Two are certainly so, one of the latter (Mr Holthouse’s case) showing calcareous degeneration.