BACTERIUM LEPRM 147 



Some immunity is left after an attack, and use has been made 

 of the serum in treating the sick. As there are several species 

 of this spirochete, differing very slightly, it is necessary to 

 use many varieties to make an antiserum. 



BACTERIUM LEPR51. 



Leprosy is a chronic endemic infectious disease charac- 

 terized by the development, in the skin chiefly, but also the 

 mucous membranes, of firm nodules and diffuse swellings due 

 to the growth and irritation of the Bacterium leprce or leprosy 

 bacillus. 



Forms of Leprosy. There are two forms', the nodular and 

 anesthetic. The former is usually painless throughout its 

 course, merely giving rise to the cutaneous nodules. The 

 anesthetic form is due to an involvement of the sensory 

 nerves, which are at first irritated with the production of a 

 painful .early stage, followed by destruction of sensation 

 when the inflammation has progressed further. The disease 

 gives rise to considerable superficial destruction of tissue, 

 which is responsible for the horrible pictures of this disease 

 in the lay mind. Fingers, toes, nose, and pieces of skin may 

 be removed by ulceration. The disease is an old and wide- 

 spread one, commonest in the tropics, but by no means 

 confined to them. Despite long familiarity with leprosy, 

 there are many points as yet undecided about its nature. 



Transmission. The bacteria probably enter by the nose 

 and mouth, and it requires close association with a leper for a 

 long time in order to contract the disease. It seems that it 

 may be hereditary in the sense that parent and child may be 

 infected. It is much more probable that the child is born 

 free of disease and acquires it by association with the parent. 

 The low contagiousness of leprosy should be emphasized. 

 If one should say in a crowd. "There is a leper!" the people 

 would shun him as if he were a maniac with a firearm. If 

 one were to say under similar conditions, "There is a con- 



