On the etiology of leprosy / by G. Armauer Hansen.

  • Gerhard Armauer Hansen
Date:
1875]
Catalogue details

Licence: Public Domain Mark

Credit: On the etiology of leprosy / by G. Armauer Hansen. Source: Wellcome Collection.

    13/66 page 463
    The assumption of heredity is based on the relatively frequent occurrence of several lepers in the same families. Among the 528 lepers registered by Bidenkap! there were 135 without leprous rela- tions in the ascending line or in collateral lines, 268 had leprous relations in collateral lines, 125 in the line of direct ascent. This last proportion is nearly the same as that calculated by Dr. Hoegh for the whole country. Bidenkap says, “It seems thus to be something constant, applying to the whole country or to any single | part of it, that from one fifth to one fourth part have had leprous | ancestors, and at least about one fifth leprous parents.” This seems to be confirmed by tae proportion among the 210 cases now registered by me, among which 5] have leprous relations in the line of direct ascent, 50 no leprous relations, and 109 have them in the collateral line. My tables are taken from another part of the coun- try than Bidenkap’s, which seems still more to confirm the rule. The proportion, however, falls out very differently in several smaller dis- , there are none with leprous ancestors ; and it is, perhaps, remarkable | that where the appearance of leprosy may be considered as relatively of recent date, there is very seldom any relationship between the lepers, nor do the latter descend from leprous families of any other . places. It is not until leprosy has become endemic that the cases occur which might indicate heredity. If, now, the disease was con- tagious, this might have a very natural explanation, as the first case of leprosy acquired by contagion elsewhere would afterwards most — frequently infect those in nearest intercourse, members of the same family or relatives. In any case the number of lepers for whom even with the strictest search no leprous ancestors can be discovered, and of those for whom no leprous relations can be pointed out, is so great that one fourth or one fifth of suchas have leprous ancestors is too smalla proportion to prove heredity. After what I have already stated as to the improbability of degeneration or special disposition to sickness in the people, or of any circumstance peculiar to us for con- tracting leprosy, it will by no means be unjustifiable to refer all cases without demonstrable leprosy in the line of direct ascent to | those which cannot be classed in connection with heredity, and then the number of these cases will be so great that heredity will appear improbable. With regard to pellagra, it has been endeavoured to prove heredity in the same manner by recording a great many family cases. But now it has been shown in respect of this disease that if indi- viduals go beyond the influence of the home infection they do not only not get pellagra, but that even if they have previously suffered from it, the disease disappears under the altered conditions, while it ' “Norsk Magazin for Lagevidenskab’ (Norwegian Magazine for Medical Science), 2nd series, vol. xiv.
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