Mycobacterium leprae is a bacterium which causes a progressive, chronic bacterial infection called leprosy. The nerves in the nose’s lining, the upper respiratory tract and in the extremities get affected by it. Leprosy produces nerve damage, muscle weakness and skin sores. If not treated, it may result in significant disability and severe disfigurement. Leprosy is quite common in lots of countries, especially those having subtropical or tropical climates. Leprosy has been classified in three different ways. The first kind recognizes two different leprosy types: lepromatous and tuberculoid. The immune response of a person towards the disease, dictates the kind of leprosy. Only few skin sores show and there is good immune response in people having tuberculoid leprosy. The disease isn’t severe and is not highly contagious. In those having lepromatous leprosy, immune response isn’t high and the nerves, skin and few other organs are affected. Nodules and wide spread lesions are found. It is highly contagious. Another way of classifying it is dependent on the number of skin areas affected and the type. Paucibacillary is the first type which has five or lesser lesions without any bacteria detection in the samples taken from the skin. Multibacillary is the second category which has higher than five lesions, bacteria gets detected in the skin’s smear or even both. An infected individual’s mucus can lead to the spread of leprosy. This usually happens when an infected individual coughs or sneezes. The disease is not highly contagious. Close contact repeatedly with someone who hasn’t been treated can cause transmission of leprosy. The bacteria causing leprosy multiply slowly over a long period of time. The disease can incubate for over five years. Symptoms might not show up till 20 years. The doctor can carry out a physical examination to search for symptoms and telltale signs of the disease. They also carry out scraping or skin biopsy. The doctor removes a small part of the skin and sends the sample to the lab for testing. They might even conduct lepromin test of the skin for determining the kind of leprosy. The doctor injects a tiny amount of leprosy inducing bacteria in the skin, usually in the upper part of the fore arm. People having borderline tuberculoid or tuberculoid leprosy have irritation at the site of injection. The World Health Organization has come up with a multiple drug therapy for curing all kinds of leprosy. It is available worldwide for free of cost. Quite a few antibiotics are also available for killing the leprosy causing bacteria. Your doctor might prescribe multiple antibiotics at once.