Mycobacterium Laprae
Leprosy (Hansen’s disease)
Jillian N. VanBenthuysen
Microbiology, BIO105
Dr. Heather Marsden
5 May, 2010
Leprosy, also known as Hansen’s disease is a very old disease that is extremely misunderstood. It is caused by a bacterium called Mycobacterium Leprae (M. Laprae). Surprisingly, Leprosy is a very common disease and is found in every corner of the world. In the United States alone between 100-300 new cases are found every year. (“Leprosy,” 2009) (Davis, 2009) Around the world approximately 500,000 to 700,000 new cases are diagnosed each year. (Davis, 2009) Leprosy can be cured and if people understood how it worked there is a possibility that the stigma which is associated with the disease can come to an end.
Leprosy is caused by rod-shaped bacilli. M. Leprae is an obligate intracellular bacterium, which means it can only grow within human or animal cells. It is an acid-fast bacterium and for microscopic viewing in stains red on a blue background. (“Mycobacterium leprae,” 1996)
M. Laprae prefers to grow in our body’s macrophages and Schwann cells. Unlike most bacteria, M. Laprae grows and reproduces very slowly. On average it takes about 12-14 days, whereas most bacteria complete this cycle in hours or even minutes. (Davis, 2009) Scientists still have not been able to culture it in a lab on any type of media or cell culture however; they have been able to grow the disease in the feet of mice. (“Hansen’s disease (leprosy),” 2009)
How leprosy is transmitted is still not fully clear. It is believed that it is spread through nasal secretions and respiratory droplets also; you need prolonged contact with an infected person. Some people are considering the idea that the bacteria may be able to enter the body through cuts in the skin. Researchers do know that it cannot enter as long as your skin isn’t damaged. Transmission is mostly from human to human. There are three animal species, nine-banded armadillos, chimpanzees, and mangabey...