font size

Leprosy (cont.)

Medical Author:
Medical Editor:

What causes leprosy?

Leprosy is caused mainly by Mycobacterium leprae, a rod-shaped bacillus that is an obligate intracellular (only grows inside of certain human and animal cells) bacterium. M. leprae is termed an "acid fast" bacterium because of its chemical characteristics. When special stains are used for microscopic analysis, it stains red on a blue background due to mycolic acid content in its cell walls. The Ziehl-Neelsen stain is an example of the special staining techniques used to view the acid-fast organisms under the microscope.

Currently, the organisms cannot be cultured on artificial media. The bacteria take an extremely long time to reproduce inside of cells (about 12-14 days as compared to minutes to hours for most bacteria). The bacteria grow best at 80.9 F-86 F, so cooler areas of the body tend to develop the infection. The bacteria grow very well in the body's macrophages (a type of immune system cell) and Schwann cells (cells that cover and protect nerve axons). M. leprae is genetically related to M. tuberculosis (the type of bacteria that cause tuberculosis) and other mycobacteria that infect humans. As with malaria, patients with leprosy produce anti-endothelial antibodies (antibodies against the lining tissues of blood vessels), but the role of these antibodies in these diseases is still under investigation.

In 2009, investigators discovered a new Mycobacterium species, M. lepromatosis, which causes diffuse disease (lepromatous leprosy). This new species (determined by genetic analysis) was found in patients located in Mexico and the Caribbean islands.

What are the risk factors for leprosy?

People at highest risk are those who live in the areas where leprosy is endemic (parts of India, China, Japan, Nepal, Egypt, and other areas) and especially those people in constant physical contact with infected people. In addition, there is some evidence that genetic defects in the immune system may cause certain people to be more likely to become infected (region q25 on chromosome 6). Additionally, people who handle certain animals that are known to carry the bacteria (for example, armadillos, African chimpanzee, sooty mangabey, and cynomolgus macaque) are at risk of getting the bacteria from the animals, especially if they do not wear gloves while handling the animals.


Patient Comments

Viewers share their comments

Leprosy - Symptoms Question: What were the symptoms of leprosy in you or someone you know?
Leprosy - Risk Factors Question: Have you ever been at risk for leprosy, either through travel or work? Please share your story.
Leprosy - Treatment Question: If you know or have helped someone with leprosy, what was the treatment for the disease?
Source: MedicineNet.com
http://www.medicinenet.com/leprosy/article.htm

Women's Health

Find out what women really need.

Leprosy Related Articles
advertisement
advertisement
Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations