Mycobacterium lepraeleprosy is an obligate, intracellular parasite that causes a chronic mycobacterial disease in man. This rod-like bacillus with a length of 2-7 um and a width of 0.3-0.4 um (1 um=1/1000 of a mm), was first discovered in 1873 in Norway by G. Armauer Hansen. This is why this organism is sometimes known as "Hansen’s bacillus" and the disease it causes, is known as "Hansen’s disease". This bacillus has a waxy coating and is Gram-negative. The Gram-stain does not work for this bacteria because its waxy coating will not take the dyes involved in the stain. Instead, a different staining method is used called Ziehl-Neelson Stain, which removes the waxy coating with detergent before staining them. It is Acid-Fast and Alcohol-Fast. Their waxy coat helps protect them against the high acidity of the stomach. This bacteria still cannot be cultivated artificially in laboratories. Although, it has been made to grow in the cool foot pads of mice and in the 9-banded Armadillo.
This bacteria is very slow in reproducing. The major source of spread of this infection is probably nasal secretions of lepromatous patients, which have high concentrations of bacilli. Shared clothing and sleeping mats may also source of infection. Infected soil and insect vectors (i.e. bedbugs, mosquitoes) are thought to play a role in this bacteria’s propagation. Also, exposure to infected armadillos may be one mean of acquiring this disease. The armadillo is an identified carrier of the disease and infected armadillos have large numbers of bacilli in nasal secretions and mammary ducts. Since living Mycobacterium lepraeleprosy produce no toxins and have no motile power, it is thought they cannot enter unbroken skin or intact mucous membranes. Instead, it is believed that they can only enter through a break in the skin and the mucous membrane of the nose. Its key targets are the nerves’ Schwaan Cells. This bacteria exists throughout the world, but it is most common in tropical areas, such as Asia, Africa, Central and South America, Oceania, and even Mexico. It is very uncommon in the United States. As a matter of fact, ninety percent of US cases involve patients who have lived in foreign countries where the disease is endemic.
The most congenial environment of this bacteria is a eukaryotic cell, in most cases human but sometimes of the Nine-Banded Armadillo, the mouse foot-pad, and the monkey, but to a lesser degree. It is very common to find this bacteria in the body’s cooler regions, particularly the skin and the surface nerves. This is the reason for why it is a very visible disease.
Leprosy leads to a variety of health problems. It causes deformities, disability and more. The clinical appearance of Hansen’s disease depends on the patient’s immune response to the bacteria. Leprosy usually starts with characteristic lesions. Lesions are one or more flat or raised patches that appear on the skin. Often, these patches have a raised, reddened margin and a scaly, hairless, light-colored interior. Typically the middle of the lesion is numb. It also damages the nerves in the face, arms, and legs. It causes crooked hands, a nodulose swollen face, and/or sores on their hands and feet. The visible disabilities and deformity lead to much fear and stigma from which the affected people suffer. This is unfortunate because these sufferers are ashamed and shy to admit they have it, and therefore do ask for or come for treatment at the start of the disease. This initial neglect for treatment is harmful because the sufferers start treatment when it is too late and there is nerve damage. These damaged nerves result not only in paralysis but also in a loss of sensation. This loss of sensation in hands, feet, and eyes means that everyday activities are very dangerous for them. Burns can go unrecognized, wounds untended, stones in shoes, and grit in the eyes. All these dangers are undetected and untreated by the sufferer due to the loss of sensation. The end result can be the loss of sight, fingers, and feet. It can also be the cause of nose cartilage destruction, but this is quite rare. This bacteria also damages peripheral nerves, which are the nerves that connect the central nervous system (the brain and spinal cord) to the muscles, skin, and internal organs.
There are some other very harsh and painful presentations of Hansen’s disease, other than the amputation or loss of body parts. First of all, if the disease induces a skin reaction similar to erythema nodosum lepprosum (ENL), widely, disseminated, painful, nodular lesions form. These form all over the body as well as on the face. There is another form of the disease usually reported in Mexican patients, that have diffuse infiltration and thickening of the skin. With this form, leprotic nodules are absent, but frequently there is a gradual loss of eyebrows, eyelashes, and body hair. Throughout the patient’s course of the disease, multiple painful ulcers usually form. Also, the disease gets very bad if it isn’t treated. It can be a very disfiguring disease in which many patches and bumps appear on the arms, legs, chest, abdomen and back over several years. The skin of the face, eyebrows and ears become swollen and shiny. The face could even eventually take on a lion-like appearance as the eyebrows are lost and the nose cartilage is destroyed. In men, the disease can destroy the testicles. This causes a decreased in the testosterone levels which then lead to breast development.. Other complications include narrowing of the larynx and the loss of bones of toes and fingers. After many years, so many nerves of the body can be destroyed that the patient is unable to feel sensations.
Mycobacterium lepraeleprosy has caused disease worldwide in 12 million people. This number includes those on treatment, and those who have finished their treatment but have a disability, or are stigmatized or suffering socially. About half of these people have history of intimate contact with an infected person, who is usually a household member. Anyone can get the bacteria in their systems, although it usually only occurs in the endemic places. Also, it seems as though children are most susceptible than adults.
Since this bacteria cannot be laboratory cultivated, there has been much frustration and delay in finding an effective anti-leprosy vaccine. Despite this, treatments have been found. The treatment is called Multidrug Therapy (MDT) and involves using three antibiotics: Dapsone, Rifampicin, and Clofazimine. These three antibiotics are very effective in getting rid of the germs. Mild non-infectious cases of leprosy require treatment with two of the drugs for a period of 6 months. More severe infectious cases involve the use of all three drugs for 24 months. Recent advances in treatment have resulted in a significant decline in the worldwide prevalence of the disease. It is very important to get treated immediately upon developing the disease. In most cases, it takes three months after beginning treatment for an infected person to not affect others around them. Hansen’s disease is totally curable, even though it sometimes has lasting deformities and psychological problems afterwards . The best way of prevention of the spread of this disease is the early diagnosis and treatment of infected people. It is recommended that after contact with an infected person, a person should have immediate and annual examinations for at least five years after the contact.