Since 1815, possibly earlier, leprosy has prevailed among the poor French settlements along the Miramichi River, near the Bay of Chaleurs, New Brunswick. It was first noticed in a woman whose mother came from Normandy, and has continued mainly in her descendants since. No measures were taken to control the disease until 1844, when a hospital was erected on Sheldrake Island. In 1849 the present lazaretto at Tracadie was established. During the first five years (1844-49) there were admitted 32 patients; from 1849 to 1863, 67 additional patients were received; and from the latter date to 1879, 30 more, making a total number of 129 up to the last report. The greatest number present at any one time was 37. In 1878 there were 16 patients in the lazaretto—6 men and 10 women. The total number of deaths in the hospital has been, up to 1878, 123. A. C. Smith, who resides near Tracadie, states that at the latter date but three cases were known to exist outside the lazaretto. Residence is not compulsory, and no sufficient measures are taken to remove patients from their homes before they may have inoculated other members of the family. The disease is more restricted in locality than formerly.
Within the last two years two or three small groups of the disease have been discovered in the island of Cape Breton, which are described in the Canadian Journal of Med. Science, Sept., 1881.
These are all the places north of Mexico where the disease exists in an endemic form. A considerable number of cases have been reported within the past few years from other parts of the United States, where it has manifested itself in persons who have formerly resided in leprous countries or in those who have wandered from the above infected districts. A very few instances have been recorded in which it has appeared in those who have never visited any infected locality or have been in apparent contact with lepers. Such cases, if authentic, establish the possibility of a sporadic origin of the affection. The fact of so many foci already established, and the penetration of a race so prone to the disease as the Chinese into all parts of the country, give the study of leprosy in America a special importance.
ETIOLOGY.—The study of the etiology of leprosy is intimately connected with that of its history and geographical distribution. From the earliest times it was regarded in all parts of the world as a contagious affection, and efforts were made by the sternest laws of Church and State to control its spread by segregation, by interdiction of marriage, etc. No disease has ever been regarded with an equal degree of abhorrence by mankind; none has received greater attention from physicians of every age. Within the present century it has come to be regarded, almost without exception, by the profession as non-contagious. Peculiarities of climate, soil, and modes of life have been looked upon as predisposing, exciting, or even essential influences in its causation; but the widespread distribution of the disease, with the consequent diversity of diet and customs of living, its prevalence upon the coast and in interior regions, in high altitudes as well as at the sea-level, in Iceland as in the tropics, show that these conditions, however they may affect the course of the affection, have no direct relation to its causation. The theory of heredity, as the most plausible explanation, has received its strongest support in the investigations of Boeck and Danielssen in Norway, where the disease can be traced for several generations in families. The same conclusions readily present themselves where the disease is studied in restricted localities, as in Louisiana and New Brunswick at the present time, where, as we have seen, it manifests itself closely in families in different generations. But this is a narrow point of view from which to study the etiology of leprosy. It often fails to manifest itself in the descendants of lepers in such communities, and affects persons in whose families it has never previously existed. Moreover, in countries where it does not prevail it not infrequently attacks individuals who have at some time visited regions where it was endemic, and in the latter places may develop in immigrants from parts of the world where it has never existed.
The same class of facts which seem to demonstrate its hereditary nature may be used in support of its infectious character. The proper field for observation in this regard would be a virgin region where its natural course could be studied independently of theories. Fortunately for science, such an opportunity is afforded in the history of the disease in the Hawaiian Islands. The exact date and mode of its introduction there are not definitely known. The islands have for years been the resort of the whaling-fleets manned by sailors coming from leprous regions. The natives also shipped as sailors, and after visiting such ports returned home. The absence of any restraint in the intercourse of crews and native women is well known. Isolated cases may have occurred as far back as 1830, but the disease made slow headway until about 1860, when it increased so rapidly that the government took stringent measures to control it, all cases discovered being sent to the leper segregation upon an island from which there is no escape. Since 1866, 2000 cases have been received there, and at last report the asylum contained 750 inmates. This by no means represents the extent of its prevalence in the islands, however. As the native population by recent census was only 44,000, it will be seen that the proportion affected is very large. This unwonted rapidity of spread cannot be accounted for on the ground of heredity. Transference from individual to individual by inoculation seems to be the only possible explanation, and all resident physicians believe that the disease is contagious in this sense. It affects almost exclusively those of native descent, and their habits of life are such as would greatly facilitate its wide dissemination in this way—viz. their great licentiousness and absence of all fear of the disease, which affords no bar to ordinary association or cohabitation; the crowding of large families in small huts and sharing the same mats and blankets; the eating of poi with the fingers from the same dish; passing a common drinking-vessel or pipe from mouth to mouth, etc.7 Promiscuous and compulsory vaccination with impure virus, too, has been generally practised during recent epidemics of small-pox. It is evident that abundant opportunity has in many ways been presented for the inoculation of pus or blood into the circulation from infected to healthy persons. Where immunity from contraction has followed marriage with a leper, it may be assumed that the conditions of an abraded surface and the contact with pus or blood have not been fulfilled. The wide spread of syphilis among the natives, and a consequent cachexia, have no doubt contributed to these conditions and established a national lack of resistance to the ravages of the disease. Nor can we overlook the proclivity of all endemic diseases to extraordinary manifestations of virulence in insular nations not previously protected by gradual inoculation. Many reliable cases are cited by resident physicians where the evidence of direct communication of the disease seems to be reliable. Facts of the same nature may be collected in the study of the history of the disease in New Brunswick and in Louisiana, where, as above stated, much better fields for investigating this question exist than in the Old-World regions where the affection has been rife for centuries.
7 Dr. G. W. Woods, U.S.N., in Hygienic and Med. Reports of Navy Department, vol. iv., 1879.
If we admit the fact of transference by inoculation in a single instance, there is no reason why we should not regard this as the principal if not the only means of extension of the disease, whether we accept or not the theory of its parasitic nature. It is not inconsistent with our knowledge of its laws and history to believe that leprosy is an affection communicated with difficulty, and after a prolonged period of incubation, from one person to another by contact with certain products of the diseased tissue; that it has in past and present time in this way spread from nation to nation; and that its progress as an endemic affection has been checked only by laws based upon this theory. All the negative facts so frequently urged against this doctrine of contagion apply as strongly to that of heredity, and may be interpreted in support of the former. The latest investigations into its pathology afford tangible evidence in its favor. It may at least be claimed that the question of contagion through inoculation must be reopened.8
8 See article on the question of contagion in leprosy in the American Journal of Med. Sciences, Oct., 1882, by the writer.
Leprosy affects both sexes in about equal degree, and may first show itself in early childhood. It is apt to produce sterility, so that marriages between lepers are rarely fruitful. This result seems to limit the extension of the disease under the law of heredity if we admit its action. There can be no doubt that cohabitation may take place for years without communication of the disease where one party alone is leprous; and such immunity may be explained by the failure of favorable conditions for sexual inoculation, just as in syphilis. The disease would naturally be most dangerous in its ulcerative tubercular form.
SYMPTOMATOLOGY.—There are two well-marked forms of leprosy—viz. the tubercular and the anæsthetic—which are characterized by certain easily recognized external manifestations, and which are accompanied by symptoms indicative of disturbances of the general economy as well as of special organs. These forms are not always sharply defined, and often occur simultaneously or in succession in individual cases. Both are generally preceded by premonitory symptoms, consisting of unaccountable languor of mind and body, tingling sensations in the skin, rise of temperature in the evening, and various disturbances of digestion, or by the occasional outbreak of single or several blebs. This prodromal stage affords no indication of the type of disease to follow, and may last for days, months, or even years, with greater or less intervals and intensity.