Leprosy is also known as Hansen’s disease, after the scientist who discovered M. leprae in 1873.

Taxonomy
Family: Mycobacteriaceae

History
Leprosy has been around since ancient times, often surrounded by terrifying, negative stigmas and tales of leprosy patients being shunned as outcasts.

Outbreaks of leprosy have affected, and panicked, people on every continent.

The oldest civilizations of China and Egypt, and India feared leprosy was an incurable, mutilating, and contagious disease.

Natural habitats
This bacteria is believed to live in the soil.

Scientists think that the reservoir for this bacteria is the new world armadillos and African primates.

At the beginning the idea that the habitat of this bacteria was in soil was just an hypothesis but some research were done and DNA of the M. leprae was found in soil close to where people were infected with leprosy.

Its ideal temperature is about 30-33oC

Clinical significance
Leprosy
Is an infectious disease that causes severe, disfiguring skin sores and nerve damage in the arms and legs.

Leprosy is actually not that contagious.

You can catch it only if you come into close and repeated contact with nose and mouth droplets from someone with untreated leprosy.

Children are more likely to get leprosy than adults.

Symptoms
Leprosy primarily affects the skin and the nerves outside the brain and spinal cord, called the peripheral nerves.

It may also strike the eyes and the thin tissue lining the inside of the nose.

The main symptom of leprosy is disfiguring skin sores, lumps, or bumps that do not go away after several weeks or months.
The skin sores are pale-colored.

It usually takes about 3 to 5 years for symptoms to appear after coming into contact with the leprosy-causing bacteria. Some people do not develop symptoms until 20 years later.

There are three forms of the disease, with lepromatous being the most severe, tuberculoid, and borderline leprosy.
The precise mode of transmission is not fully understood.

The bacteria are likely spread by direct contact and through air dispersement, from coughing or sneezing.

Manifestations
Infected individuals will notice skin lesions in early stages, leader to paralysis or loss of sensation in those areas, and eventually loss of extremities.
Blindness can occur as the disease advances.