Unsuspected sources of leprous infectious

Everybody thinks himself to be at a safe distance from leprosy without knowing where he stands. The general opinion is that it is only to be found among the beggars and the lower class people, that it is an hereditary disease, it visits only those who have sinned in their life, and that the workers in connection with a leprosy clinic are most likely persons to get this disease

Seasonal variations in leprosy in Calcutta

1- Analysis of the records of new cases appearing at the Calcutta leprosy clinic over a period of two years )1936-1938, 2,779 cases) shows that larger numbers per month come between March and October than in the rest of the year. 2- This seasonal increase is found to occur in the neuromacular cases and not in those of the lepromatous type or of the neural type without macules. The seasonal variation in the clinical and bacteriological findings in the 1902 neuromacular cases is studied. 3- It is found that clinical signs of activity in the form of thickening, erythema and radial extension are more common during the months from March to September than at other seasons. 4- It is found that during the months of March, April and May the percentage of neuromacular lesions in which bacilli are found in smears rises markedly, reaching a maximun of about 23 per cent in April or May, and that it falls to below 5 percent in June; during most of the year the percentage is below 10. 5- These findings are interpreted as demonstrating: (a) that in the early months of the year, bacilli in neuromacular lesions tend to multiply increased cellular activity; (b) that the bacillary increase tends to end abruptly in the month of june;and (c) that the increase in cellular activity subsides a few weeks after the bacillary increase has subsided. 6- The causation of these seasonal variations is discussed in the light of the publications of Stein, who attributes a seasonal incidence of lepra reaction to sudden changes in meteorological conditions, and of Oberdoerffer, who attributes seasonal variations seen in Africa to varying consumption and varying toxity of cocoyam (Collocasia antiquorum) at different times of the year. Neither of these factors seems to explain the seasonal variations seen in Calcutta. 7- The seasonal variations in Calcutta appear to be related to meteorological conditions, the period of increased bacterial activity being confined to the hot, relatively dry season and ending abruptly with the onset of the rainy season, the cellular activity gradually subsiding later.

Thickened nerves in leprosy in relation to skin lesions

Observations have been made on tickened nerves in relation to skin lesions as seen in a clinical study of 3,079 cases of leprosy. The area of deep analgesia is usually less than that of superficial anesthesia. As repair progresses, the anesthesia usually persists longer than the analgesia. From the clinical findings it seems that in the ascending type of nerve lesion the infection spreads by lymphatics from the skin lesion. The reasons why the nerves are found thickened in their superficial course, like the ulnar behind the elbow, are that there is space for the nerve to swell, and that because the lymphatics and blood vessels of the part are not under pressure of muscles, stagnation may occur and therefore the infection finds time to work out its course. This also explains aberrant findings in which infection may spread by collateral branches of lymphatics to the nerves adjacent to the skin lesions...