762
THE NEW ZEALAND GAZETTE.
[No. 31

bacilli do not evolve any fermentation. A temperature between 25° and 37° C. is almost equally suitable to their growth. Between 10° and 15° C. growth is slow, but still vigorous, and even at a temperature of 5° C. it is not absolutely impossible. If the germ used for their propagation has been taken from the patient or the dead body their growth is slow, even under the most favourable conditions of warmth. Upon the surface of solidified agar, for example, that is kept at 37° C., the first beginnings of a colony visible to the naked eye do not appear before the lapse of twenty-four hours, and for full development twice to three times that period is required. Surface-cultures consist, then, of fragile little drop-like colonies, transparent under the microscope, and showing little propensity to run together. Under soup-cultivation the plague-bacilli grow abundantly in the form of streptococci-like chains of varying length. Cultivated upon very dry agar, especially upon agar containing from 2 to 3 per cent. cooking-salt, the plague-bacilli take in from one to two days numerous quite extraordinary involution-forms—large globular shapes of irregular build, which, for the most part, can only be imperfectly coloured with aniline dye.

Permanent forms of the plague-bacillus are not known.

In fluid media warmed up to 55° to 60° C. the bacillus dies in ten minutes; boiling-heat kills it at once. Dried on linen and the like materials, it may in our climate retain vitality for many weeks.

Plague-bacilli are to be found in all products of sickness of the living, and almost throughout the whole body of a patient who has succumbed to the plague. The pus and tissue of fresh bubos and carbuncles, the inflammatory exudations in the lungs, contain bacilli in appalling numbers. In the contents of a spontaneously breaking or incised bubo they are only exceptionally found, so that in all cases of gland-plague which end in convalescence they must be got at by incision of the bubo when fresh. Such cases, anyhow, give but little scope for diagnostic doubt or error. Blisters and carbuncles yield, when opened, material for bacteriological diagnosis. In most cases of lung-plague the sputum contains numberless bacilli, and affords sure means of diagnosis. Failing sputum, a section or puncture of the lung in the dead body would decide the question, supposing it had not been already settled by bacterological examination of the blood. But an examination of the blood should not be neglected in any case of plague, for it is always easily carried out, and is often decisive. In the majority of plague patients who die one can find in the last hours of life, sometimes a few days before, bacilli, either few or in numbers, in a drop of blood obtained by a needle-prick from any part of the skin. From the normal excretions, saliva, sweat, urine, milk, menstrual fluid, lochia, they are more difficult to obtain and less frequent. In terminal lung-oedema they invariably appear in masses.

Should bacteriological examination of the living patient be from any reason impracticable or fruitless, that of the dead body is always easy and sure, especially if one submits to the test of the microscope, the examination of tissue-sections and prepared specimens, and the inoculation of a rat or mouse. Beside the primary localisation in the skin, glands, or lungs, the blood, spleen, lung-foundations, gall (duralflüssigkeit) are materials specially adapted for getting traces of bacilli.

Above all a post mortem reveals for the first time many cases of plague which remained unrecognised or uncertain during life. The anatomical condition is usually more uniform and on that account more characteristic than the aspect of the sickness. Besides the primary lesions, the fatty or marrowy lymph-glands, the saline, bloody, far-reaching absorption of the neighbouring tissues in one case, the carbuncle with deep-reaching infiltration of underlying parts in another, the thickening of the lobes or lobulars of the lung in a third, one finds in almost every corpse a soft swollen spleen, colourless blood, and invariably effusion of blood in different organs, especially abundant in the stomach, thin gut, cæcum, basin of the kidneys, &c. Further, one finds here and there “herdförmige necrosen,” and a high degree of parenchymatous degeneration of the glandular internal organs, and especially of the liver.

The most important considerations in the treatment of plague patients are a good situation, fresh air, cool spongings. The great thirst of the patient should be alleviated without stint. Fresh water, acid drinks, milk are his favourite beverages. Many doctors advise against stimulants in cases of pronounced depression of the brain and vital centres. A cleaning-out of the bowels by castor-oil or similar mild measures is recommended by some medical men, and it appears effective as a ground of general health, which affords free exit to accumulations of blood formed through mechanical irritation or constipation of the bowels. As to the expediency of heart-stimulating methods in cases of plague medical men are not unanimous.

To cauterise or destroy the existing plague-pustule an application of grey ointment, lotions of sublimate or carbolic over the inflamed lymphatics or bubos, appear effective. Further treatment of the bubos must be surgical. For patients with lung-plague the inhalation of 1 per cent. of carbolised lime-water spray is recommended.

The best protection for doctor and nurse is perfect and scrupulous cleanliness. The grave danger of infection through the sputum of the lung-plague patient, and through the exudation from the lungs of the dying, is especially to be guarded against.

There must be disinfection of everything that passes from the patient, and it must extend to everything that comes in contact with him. Of chemical disinfectants the following are particularly suitable: Solutions of sublimate, one in a thousand; carbolic, 3 per cent.; solution of kresol soap; as well as chlorate of lime, 2 per cent.

As a preventive measure—more especially for the protection of doctors and nurses—the question of inoculation with deadened plague-cultures, the so-called active preventive process, “immunisirung,” is worth considering. This plague-preventive inoculation is, as the wholesale inoculations in India have shown, not dangerous, and affords protection, if not infallible at least unmistakable, against infection. It must above all things, however, be taken into consideration that, so far as animal experiments afford a means of judging, inoculation does not display its protective operation until after seven days.

Following the analogy of the diphtheritic serum, the serum of animals rendered in a high degree immune from the plague-bacillus has also been recommended, both as preventive and means of cure. But, notwithstanding its clearly marked characteristics in animal experiments, the plague-serum has not as yet shown itself capable of producing any generally accepted results in human plague.

To treat the matter as an epidemic: In our opening remarks it has been noticed that the plague, after its introduction, at first spreads but slowly. Frequently cases are limited at the beginning to the families of those first attacked, or to persons who become infected by nursing or visiting them. Soon, however, they extend, still in small numbers, to the neighbouring houses, or even to distant quarters, attacking persons who cannot be shown to have been in any way in contact with the early victims. So the epidemic, if the soil be congenial and it is left to itself, gradually finds a home in the course of weeks or months; but its subsequent progress is swift, according to circumstances, until, after reaching its highest point, it dies away, at first quickly, and then more slowly. Its extinction is often only apparent; after an interval of respite lasting for weeks or months not infrequently a fresh epidemic may start, and this again be succeeded by others.

Epidemics of such sudden development as may occur in the case of Asiatic cholera and abdominal typhus, in consequence of the disease-germ finding its way into drinking and household water, are not observed in the plague.

A marked feature in the behaviour of the plague is its tendency to fasten on individual houses and specially devastate these. If the early attacked houses are vacated and the inhabitants transferred elsewhere, the latter usually remain free from infection.

In the dissemination of the plague the transmission of the disease-germ from man to man takes the foremost place. The process may be immediate, or it may be that linen, clothing, or other articles which have come in contact with a sick person serve as intermediary agencies.

The manner in which the disease-generator leaves the body has already been described. The danger of infection is usually slight in the milder cases of glandular plague, in which the disease-germ is at first imprisoned in the swollen gland; and the case is hardly different when the bubo becomes soft and breaks, for under these conditions the plague-bacilli are, as a rule, already dead. The liability to infection is quite different, however, in severe cases of septicaemic gland-plague, in which the disease-germs may be secreted even during life along with the different bodily secretions, especially massing together shortly before death in the lung-oedema. The most dangerous source of infection are patients with lung-plague, owing to the masses of plague-bacilli in the sputum, which, by cough or by merely speaking, are launched in the air in the form of the tiniest particles.

The plague-germs detached from the sick find an entrance into the lymph-ducts of the healthy by small, generally unnoticed abrasions of the epidermis, scratches, flea-pricks, and such-like. In other cases they nestle first in the mucous membrane of the mouth or fauces, or on the tonsils, possibly also pass from the conjunctiva into the nostrils, or finally are breathed into the bronchial tubes from the cavity of the mouth in the course of respiration.

That these various modes of infection find special facilities of access from man to man wherever a dirty population herds together in small, dark, overcrowded dwellings is a conspicuous fact. Where light and air come in freely and abundantly, and cleanliness prevails, experience shows that there is little danger of the plague obtaining sufficient foothold to become an epidemic scourge.