I. Name of Disease
Leprosy; different forms being Lepromatus, Tuberculoid, Multibacilliary, and Paucibacilliary
II. Name of Bacteria
III. Description of the Bacteria
Mycobacterium leprae, the bacteria which causes leprosy, is a rod-like bacillus with parallel sides and rounded ends measuring 2-7 micro-millimeters in length and 0.3-0.4 micro-millimeters in width. It can only be seen under the electron microscope when stained. It is acid-fast and alcohol-fast, meaning not decolorized by acid or alcohol after staining, as most bacteria retain dye after an acid or alcohol rinse. It occurs in large numbers in the lesions of Lepromatous leprosy, chiefly in masses within the Lepra cells, often arranged like bundles of cigars. Chains are never seen. Intracellular and extra-cellular masses, known as globi, consist of clumps of bacilli in capsular material. Under the electron microscope, the bacillus appears to have a great mixture of forms. The most common is a slightly curved filament containing irregular arrangements of dense material in the shape of rods.
Short rod-shaped structures can also be seen and also dense spherical forms.
The leprosy causing bacteria are probably spread through skin breaks, such as a contaminated needle, and sneezing and coughing. The leprosy bacilli travel through the air in droplets released when people cough or sneeze. The bacteria can survive three weeks or longer even outside the human body, such as in dust or on clothing.
IV. Description of the Disease
When Mycobacterium leprae was discovered by G. Armauer Hansen in 1873, it was the first bacterium to be identified as causing disease in man. Leprosy, also called Hansen's disease, is an infectious disease that affects skin, peripheral nerves, mucous membranes, such as eyes and respiratory tract. Though slow growing, it is one of the world's most crippling diseases. The effects of leprosy are discolored...