508 PATHOGENIC MICROORGANISMS 



leprosy is most common in the eastern countries, especially in India and 

 China. In Europe the disease is found in Norway, in Russia, and in 

 Iceland. In other European countries, while the disease occurs, it is 

 not at all common. In the United States, there are, according to Osier, 

 three important centers of leprosy situated in Louisiana, in California, 

 and among the Norwegian settlers in Minnesota. The disease is also 

 present in several provinces of Canada. In all countries in which 

 segregation of lepers is rigidly practiced, the disease is diminishing. In 

 Norway, according to Hansen, proper sanitary measures have reduced 

 the number of lepers from 2,870 in 1856, to 577 in 1900. 



Clinically, the disease appears in two chief varieties, tubercular 

 leprosy and the so-called anesthetic leprosy. In the former variety, 

 hard nodular swellings appear, usually in the face, but often on other 

 parts of the body as well. These lead to frightful disfigurement and 

 are accompanied by a falling-out of hair and a loss of sensation in the 

 affected areas. In the anesthetic form, there is usually at first pain in 

 definite areas of the extremities and the trunk, which is soon followed 

 by the formation of flat or slightly raised pigmented areas, within which 

 there is absolute anesthesia with, later, atrophy and often secondary 

 necrosis in the atrophied parts. The disease is usually chronic in its 

 course. 



The bacilli are found in large numbers in the cutaneous lesions. In 

 the knobs of the nodular variety, they lie in clumps between the con- 

 nective-tissue cells and within the large spheroidal cells which make up 

 the nodules. They are found, also, in advanced cases, in the liver and 

 in the spleen, lying within the cells, and, to a slighter extent, in the 

 intercellular spaces. They have also been found within the kidneys, 

 the endothelium of the blood-vessels, and in the testicles. 1 In the blood, 

 the bacilli have frequently been demonstrated, especially during the 

 febrile attacks which occur during the disease. Westphal and Uhlen- 

 hut 2 have found the bacilli within the central nervous system, 

 and these observers, as well as others, have found them lying 

 within the substance of the peripheral nerves, thus explaining the 

 anesthesia. A fact of enormous importance to the question of 

 transmission is the observation made by various observers, more 

 especially by Sticker, that the bacilli are found with great regu- 

 larity in considerable numbers in the nasal secretions of persons 

 suffering from the disease. Sticker is inclined to regard the nose 



1 Sticker, Munch, med. Woch., 39, 1897. 



2 Westphal und Uhlenhut, Klin. Jahrb., 1901, 



