Part 61

Among the less domesticated animals that contract tuberculosis may be named deer, elk, gazelle, antelope, camel, dromedary, giraffe, kangaroo, lion, tiger, jackal, jaguar, bear, arctic fox, rat, mouse and the common cage birds, etc. Fröhner found 36 per cent. of parrots affected in Berlin.

Man has long been recognized as standing in the front rank of susceptibility to tuberculosis. Yet even in his case the prevalence of the affection bears an intimate relation to his indoor life. In large cities post mortems often show that one-third have suffered, and that one-seventh and upward of the whole population die of tuberculosis. Natives of tropical islands and countries, living in the open air and apart from close association with civilized man, often escape entirely. In South Africa the herdsmen living in close buildings suffer encreasingly, while their cattle, kept constantly in the open pasture, escape.

Geographical Distribution. The prevalence of tuberculosis shows a direct relation to the opportunity for infection rather than to climate, latitude or altitude. It is the prevailing disease of civilized communities with dense populations, and especially in large cities where the general vitality is lowered and the crowded buildings give every opportunity for infection. It is preëminently the disease of Central Europe, of Great Britain and of our Eastern States, where there is the greatest activity in business, manufacture and commerce. Yet in the Scottish Hebrides, Iceland, Newfoundland, the Greenland Highlands, Arctic North America, the northern parts of Norway and Sweden, Lapland and Finland it is hardly known. The absence of commerce and cattle and the sparse population have much to do with this. The coasts of Greenland with their Danish stations have two-thirds of the population tuberculous (Cook); the Indians of Barrow’s Straits, when infected in 1899 by the frozen-in whalers, suffered from it as from a plague; in Christiana, Stockholm and St. Petersburg it is as prevalent as in the large cities of Central Europe. Elevated and dry climates have often been found to be free from the affection, yet it prevails inside the double windows of houses in the higher Alps, and has, within a generation established a notorious prevalence in Minnesota, Dakota and westward, as it has in Australia, mainly owing to the advent of consumptives who sought for health in the dry atmosphere. The hills and dry tablelands in North and South America, Africa and Asia which have acquired a reputation for salubrity, owe this largely to the sparse population and the absence of facilities for infection. In South Africa, in spite of the dry and genial climate, the disease is constantly encreasing in the human (housed) population. The sea-coasts, which are the seats of large cities and the centres of population and trade, are also the most extensively affected with tuberculosis—in the West Indian Islands, Panama, Nicaragua, Mexico, Yucatan, Columbia, Equador, Peru, Chili, Ceylon, Guinea coast—while the sparsely peopled highlands of the same countries are practically free.

What is true of man is equally so of cattle. In the Gulf states of this country, herds living in the open air are practically free from tuberculosis, while in New Orleans and other large cities, the cows shut up in the confined stables and yards, are as tuberculous as those of the great cities of the north. So in many districts in the northern states we find no bovine tuberculosis, while in others, differing in no essential particular as regards geological formation, altitude, exposure, and industrial use of the animal, a large proportion are affected.

Virulence. Tuberculosis has long been recognized as virulent. “It is indicated in the Mishna and other Jewish works as rendering the meat unfit for consumption, but to come to more modern times, we find that throughout the seventeenth and eighteenth centuries the flesh of tuberculous animals was excluded from human food, alike by the civil and ecclesiastical laws of Europe. Tuberculosis in cattle was erroneously identified with syphilis of man, which made a frightful extension in the end of the fifteenth century, spreading from the army of Charles VIII which had been engaged in the siege of Naples. This conviction lasted until it was disproved about 1782. Though mistaken in the identity of the two diseases, the fact that for centuries the common people and physicians both associated tuberculosis with a malady so notoriously contagious as syphilis, speaks strongly for the forcible evidence of contagion manifested at that time. Morgagni, who must have begun practice about 1700 A. D., testifies to the strong conviction of the contagious element in tuberculosis. Indeed it became a common practice to isolate the consumptive person from the public, and after his death to burn his clothes and sometimes even the house, or at least to subject them to a careful disinfection. It is recorded that in 1750, in Nancy, the magistrates ordered the burning, in the public square, of the personal property of a woman who had died of phthisis, from sleeping in the bed of another consumptive person.

“At Naples, a royal edict of September 20, 1782, prescribed the sequestration of the phthisical, the disinfection of the rooms, chattels, movables, books, etc., with vinegar, eau-de-vie, lemon juice, sea-water, fumigations, etc., under a penalty of three years at the galleys, or in the case of nobles, of three years imprisonment and a fine of 300 ducats. A physician who failed to report a case of consumption was fined 300 ducats for the first offense, and banishment for ten years in case of a second. Any one assisting in such evasion of the law was sent to prison for six months.

“Chateaubriand found that, in 1803, he could not sell his carriages in Rome, because Mme. Beaumont, who had died of consumption, had ridden in them three or four times. George Sand, who was with the phthisical Chopin in Minorca in 1839, was refused a lease of the house for the second month, and the price of repainting and purifying was demanded. Later, in Barcelona, they were assessed for the bed on which Chopin had slept, as the police regulations prescribed it should be burned.

“This was not a mere survival of vulgar prejudice. Jacobi tells us of a dog which died of consumption from eating the sputa of his phthisical master. Laennec, the discoverer of auscultation, and the great authority on pulmonary consumption, records that he himself contracted a tuberculous nodule, through a wound with a saw, while making a necropsy in a case of phthisis. Laennec died of tuberculosis later, although he seemed to have checked this lesion by caustics. Andral joins Laennec in enjoining the greatest caution and cleanliness in taking care of, or associating with persons having advanced tuberculosis.

“Cullen, who started with a strong prejudice against the doctrine of contagion, leaves us the following instance of its occurrence: ‘A young man predisposed to phthisis married a Dutch girl of a sanguine temperament and good constitution. Some days after the marriage the woman lost her fresh color and was attacked by a bad cough; a month later she commenced spitting blood. The physician advised her not to sleep in the same bed with her husband, but she refused to follow his advice, and six months later she died of phthisis. The servant who took care of her and the domestic, who avoided, as far as possible, staying in the sick chamber, both died of consumption.’

“Wickmann, court physician in Hanover, in 1780, pronounces emphatically for contagion. In Zurich, at that time, one death in every six was from phthisis. The contagion of phthisis was slow in its operation, and was, therefore, less evident than that of plague, smallpox, scarlatina and other affections attended by a skin eruption, but it was no less real and deadly. It was also less frequently indirect, or carried from victim to victim by intermediate agents. He cited instances of the transmission of consumption from husband to wife and vice versa, and claimed that the marriage of a phthisical person should be legally prevented. As a means of preventing the disease, he proposed a strict surveillance of establishments for the sale of old clothes, and the avoidance of leaving infants with consumptives.

“Valsalvi and Sarconi refused to make necropsies of persons who had died of phthisis.

“Dr. Ruhling, of Gottingen, writing in 1774, of the disease in animals, says: ‘The malady is transmitted to sound animals by direct contact of animals standing side by side in the stall, and licking each other, and breathing the expired air direct from the diseased lungs; the frequenting of the same pastures will also serve to propagate it.’ In Krunitz’s encyclopedia, published in Berlin, in 1787, is the following: ‘The heifers show an ardent desire for the male, and remarkably enough, do not become pregnant, but part with the fruit of conception. When opened these animals show the first stomach, kidneys and surface of the lungs, covered with pustules like dried mulberries or in suppuration. The affection is contagious, and communicates itself from one animal to another by contact.’

“Fromage, in the Dictionaire de Rozier, Article Phthisis, says: ‘Men of art are very much in accord that this malady is not contagious, but some stock owners think differently.’

“Huzard, who saw much of tuberculosis in the Parisian dairies in the concluding decade of the last century, said that most of the veterinarians looked upon the disease as contagious, and that some of the physicians believed the same of the phthisis of man.

“Dewar, speaking of his experience in Scotland in 1839, and succeeding years, in a particular herd, says: ‘The proprietor agreed to remove partition walls, and to make openings opposite one another in the outside walls, so that there might be a current of fresh air passing through. These alterations combined with cod liver oil, tonics and stimulants, may have prolonged life but yet no cure was effected, and that herd died out. I resorted to every precaution when new cattle were purchased to prevent infection; as I had an idea, even at that time, that the disease might be communicated from one to another when in immediate contact. The precautions adopted when fresh cattle were purchased had the desired effect, for in a few years afterward, they were as good a lot of cattle as any in the district. That herd left an impression on my mind that never can be effaced, and made me always dread the evil consequences of tuberculosis. Having practiced in the same locality, which is an extensive breeding and rearing district, I have seen several herds decimated. Though I have sometimes foretold the owner what he might expect, yet he did not believe me until so many were infected that the byres were infested with the fearful malady, and your remarks in regard to nose contamination are so true that I do not think it possible any can escape that are so exposed. I have also seen, as Grad has, the same stall infecting beast after beast until a thorough cleaning and disinfecting, with plenty of fresh air had removed all infection.’

“Spinola, writing in 1858, of bovine tuberculosis, gives contagion as a possible cause, and Lafosse, in 1867, says: ‘Physicians begin in imitation of Morgagni to believe in the contagion of phthisis. The facts published by Villemin appear to support this opinion, which has been held by our colleague, Dupont, of Bordeaux, for several years.’

“Cruzel in his work of date, 1868, is much more positive; he says: ‘This fœtid expired air, inhaled immediately by another cow upon a sound lung, gives the latter tuberculous infection. It is a matter of every day experience to the veterinarian. Two oxen or cows are kept in the same stable, take their food from a common rack or manger, lie in the same stall, and respire nose to nose. The one is, to all appearances, perfectly sound, the other is in as good a condition, and is vigorous, but it coughs from time to time, and its breath is foul. Soon we notice that the animal that does not cough, eats with less appetite, he loses flesh and soon he is unequivocally affected with the same malady as the first.’ The foregoing quotations show clearly that in spite of the misleading teachings of Broussais and others, the doctrine of contagion in tuberculosis could not be overcome, and that up to the time of the remarkable experiments of Villemin, in 1865, it maintained its hold upon the minds of extensive and careful observers. In animals, especially, the evidence was so frequent and clear, animal following animal in the same stall, and eating from the same infected manger, only to be infected in turn, and two animals stalled together, and licking the same manger with their prehensile tongues, transmitting the infection with certainty the one to the other, were facts that could not possibly be ignored. Other cattle in the same building might escape for a length of time, but the eating in common from the same fatal manger, by a tuberculous and a healthy animal, quickly sealed the fate of the latter.

“Physicians, too, who were compelled to investigate the causes of the extraordinary fatality from tuberculosis in the armies and navies, could not shut their eyes to the fact notwithstanding that they came to the task strongly prejudiced through education against the acceptance of contagion. Thus, Dr. Bryson, in his report to the Epidemiological Society, in 1860, on consumption in the several ships of the English navy on the Mediterranean station, says distinctly that the disease appeared to be propagated by contagion. Dr. Parkes, quoting this in his Practical Hygiene, says: ‘It may be inferred that pus cells were largely thrown off during coughing, and floating through the air, were received into the lungs of other persons. The production of phthisis in animals confirms this view. The case of monkeys in the zoological gardens, narrated by Dr. Arnot, is a striking instance. Cows in close stables frequently die of phthisis. But not only phthisis may reasonably be considered to have one of its modes of origin in the breathing of an atmosphere contaminated by respiration, but other lung diseases, bronchitis and pneumonia, appear also to be more common under such circumstances.’

Villemin in 1865, published his investigations in which he had produced tuberculosis in a great number of animals, by inserting particles of fresh tubercle or injecting the tuberculous sputa of man into the subcutaneous connective tissues, the peritoneum and the trachea. There resulted in nearly every case a chronic disease, the marked phenomena of which were caseated centers devolving from firm inflammatory nodules in the seat of inoculation, in the adjacent lymphatic glands, in the lungs, serous membrane, liver, spleen and kidneys. The centers of such nodules were at first transparent and grayish, but soon the center underwent necrobiosis, forming a soft cheesy mass the size of a pin’s head, and gradually enlarging to that of a pea, a bean, a hazel nut or larger. After a period of about 14 days the lymphatic gland nearest the seat of injection could be felt as a firm pea-like nodule, and in two weeks more a second gland on the line of the lymph circulation, had become enlarged and nodular, while the first, now the size of a large bean, had probably undergone distinct softening. This became adherent to the skin, burst and discharged continuously or at intervals with little or no tendency to heal. If killed at this date, the animal showed only the open sore and a chain of nodular pea-like caseated lymphatic glands leading up from it. The lungs might be apparently sound, but the spleen and liver usually showed miliary elevations on the surface, with clear grayish centers, as viewed under a magnifying glass, opaque patches were found on the omentum, and the lymphatic glands of the mesentery, of the portal fissures of the liver and of the Hilus of the spleen were distinctly enlarged and resistant. If not killed, the subject usually died 100 to 120 days after inoculation, and then the lungs were found studded with tubercles miliary or larger and more or less caseated; the bronchial mediastinal, subdorsal, pectoral, prepectoral, phrenic, mesenteric, hepatic, and splenic lymphatic glands were more or less enlarged and caseated, while the liver and spleen were enlarged and studded with multiple tubercles. Guinea pigs give the most extensive and intensive lesions, rabbits much less so, but in both emaciation and wasting are very marked. In short the lesions are essentially and unmistakably those of generalized tuberculosis.

“At first, however, incredulity prevailed and experiments on a large scale were inaugurated all over Europe and America to put the question to crucial test. Martin, Conheim, Burdon-Sanderson, Simon, Wilson, Fox, Lebert and Wyss, Fraënkel, Waldenbourg, and others inoculated with all sorts of non-tuberculous organic materials (bronchial mucus, foul pus, cancer juice, diseased liver, simple cotton setons, etc.) and from these in Guinea pigs there resulted local caseated foci, and implication of the adjacent lymphatic glands. It was found that the liquids from low types of pneumonia produced these apparently tubercular deposits, while that from acute sthenic pneumonia did not; that the cotton thread seton failed to produce the disease if it were first steeped in carbolic acid, and that the lesion caused by breaking a bone without injury to the skin failed to produce the characteristic lesions even in the very susceptible Guinea pig. It became evident, therefore, that the morbid results in these cases, were due to accidental inoculations with the poison of the tubercle, which is widely distributed, or with some pyæmic or other germs.

“Gradually the truth triumphed, and those who had at first been loudest in their opposition were led by their own experiments to become the firmest supporters of the new truth.

“As early as 1874, Gerlach had experimented largely in feeding the milk of tuberculous cows, and had infected calves, pigs, sheep and rabbits in this way. Chauveau in (1874), Klebs (1873), Semmer (1880) and Parrot (1870) fed calves, cats, Guinea pigs, pigs, sheep and a variety of other species of animals with tuberculous flesh or lungs, or saliva, producing tuberculosis in a large proportion of cases. In this manner they escaped the charge of the operation of a wound and of ærial bacteria, and yet succeeded in producing infection. The lesions in this case began in the intestinal mucous membranes and mesenteric glands.

“Another essay in the same direction was made by Tappeiner (1878), who infected rabbits, Guinea pigs and dogs, by enclosing them in boxes and compelling them to breathe tuberculous liquids intimately mixed with the air atomization. In these cases lesions began in the lungs and bronchial and mediastinal glands.”

Footnote 1:

(From Report to the N. Y. Legislature, 1895. James Law.)

Bacteriology. The bacillus tuberculosis, the essential cause of tubercle, was demonstrated by Koch in 1882. It was at first supposed to be peculiar in its indisposition and tardiness to take a stain, and in its retention of the stain once imparted, even when it is treated with acids. Later observations have shown that these characteristics are common to certain other bacilli, notably to those of leprosy, smegma, and to specimens found in timothy hay and other grasses, cow dung, milk and butter. These furnish sources of fallacy in the milk and butter especially, but when the specimens examined are taken from the interior of a tubercle, lymph gland or serous cavity the danger of error may be practically ignored. What is quite as important is the fact that the tubercle bacillus is subject to evolutionary changes in adapting itself to a habitat in different genera of animals, and to a lesser extent in different parts of the same animal, by which its pathogenesis is modified, but these variations do not materially affect the staining qualities. Still more striking variations have been found in old cultures, ovoid forms (Metchinkoff), club-shaped microbes and filaments (Metchinkoff, Klein, etc.), branching filaments (Fischl, Coppen Jones), divergent club-shaped groups, like actinomyces (Babes and Levaditi). The last named, seen in inoculated rabbits, have been held to establish a relationship between the microbes of tuberculosis and actinomycosis, as the club-shaped cells do not take the usual Ziehl-Neelsen stain for tubercle bacilli, but the Birsch-Hirshfeld’s actinomyces stain. Apart from the rabbit such variations are not likely to prove sources of fallacy in identification of the microbe.

Morphology. As met with in the tubercle of man or ox the bacillus is a minute rod with rounded ends, 1.5 to 3.5μ long, by 0.2μ in thickness. In the ox it is shorter and thicker on an average than in man. They are usually solitary, but two and exceptionally even three or four elements may be united. In stained specimens unstained portions are frequently seen (spores?). When cultivated on blood serum there is a tendency to form elongated rope-like colonies having a waving outline. Other evolution forms have been already noted.

Staining. The resistance to staining is overcome by a heated alkaline watery solution of methylene blue (Koch), or better by a carbolated solution of fuchsin (Ziehl-Neelsen). To a 5 per cent. watery solution of carbolic acid add one tenth of its volume of saturated alcoholic solution of fuchsin. The suspected sputum or scraping from a section of a lesion is spread in a thin layer on a cover glass by drawing over it the straight edge of a second cover glass, dried in the air, and passed three times through an alcohol flame with the smeared side up. It may then be floated on the surface of the staining fluid with the specimen side down, then gently heated for three or four minutes almost to ebulition, drying being prevented by the addition of more of the carbol-fuchsin solution as required. It is then washed in water to remove excess of the staining fluid and treated with a bleaching acid solution (sulphuric acid 5 per cent. or nitric acid 15 per cent.) When decolorized it is well rinsed in two or more portions of a 60 or 70 per cent. alcohol and then in water. Next stain with a 1 or 2 per cent. aqueous solution of methylene blue for one minute and wash off the excess with water. The tubercle bacilli will appear of a deep red and other bacteria blue.