Leprosy - A Persisting Social Stigma

A Historical Fiasco Origin of Leprosy can be traced back to 2000 BC, as it has been authored in the religious books. The disease originated in India, from where it has been thought to spread all over the world with rise in trade and further through the impact of war.

Mahatma Gandhi was very compassionate for leprosy patients, owing more so to its increased numbers in India. He stood against all social norms that would dictate and force these patients to live in isolation and face death. It became a social stigma in the society to be infected with leprosy because of its contagious nature. Myths and misconception about the diseases took over medical facts even in civilized societies. But, Mahatma Gandhi decided to fight this delusional fear existing in the society and made his objective to help the leprosy patients and spread awareness on it.

So, for this memorable and gracious contribution to the society, 30th January; the day he passed away, is now considered as World Leprosy Day in India.

Contagious but Curable The causative agent of leprosy is a bacteria called Mycobacterium leprae (M. leprae). This bacteria was discovered by a Norwegian Scientist Dr. Gerhard Hansen, so leprosy is also called as Hansen's Disease (HD). With a complete cure available to this disease, even now more than 2,12,000 people, worldwide are affected every year. Out of this, an astounding 60% of these patients are from India, explaining the gravity of leprosy in the country.

The bacteria can be transmitted through air from the nose and mouth of an infected person. Generally, mucus droplets that are expelled in the air by an infected individual gets inhaled by people around them, thus causing the spread. Blood transfusion, breast feeding and insect bites are also lesser known causes of transmission. Noticeably, leprosy does not spread through skin contact.

Initiation-A Slow Process Once inside the body the bacteria goes into a dormant state and does not cause any harm immediately. It causes mild changes initially and takes a large amount of time to cause harm. World Health Organization (WHO) estimates that generally it takes between 5-20 years before the infection can be harmful. Although, in few cases infants and young children have been reported with symptoms of leprosy well before the age of 5 years. Since it does not show symptoms immediately post its transmission to an individual, delay in detection and therapy occurs.

Harm to the Body HD primarily affects the nerves, skin, eyes and mucus membrane (protective lining inside the body). It brings about inflammatory reactions, hence swelling or redness is seen in the patients. As the nerves are harmed, individuals loose their ability to sense and feel things on the skin surfaces of their body. Small lesions (boils) are formed on the skin all over the body including the arms, legs, neck and chest. These lesions form the basis for classification of the severity of infection. WHO has classified the infection on the basis of the number of bacteria present in the lesions on the cooler places of the body like earlobes, elbows and knees. Depending on the number of lesions it can be categorized as paucibacillary and multibacillary. If there are 1-5 lesions, it is considered as paucibacillary (few bacteria in number). Presence of greater than 5 lesions is considered as multibacillary (high bacteria in number). Higher the number, more severe the infection and accordingly the corresponding effects and changes are witnessed by the body. HD causes inflammation and disturbs the normal functioning of our cells and affects our nerves. It leads to dryness in the eyes which can further cause blindness. Our organs also fall to the might of leprosy as kidneys, lungs and heart stop functioning to its optimum level. In extreme cases it cause paralysis and make the body weak, resulting in many other infections that can harm the body.

Reactions Altered by the Bacteria Bacteria after entering the cells changes the way in which the body breaks down fat. This change benefits the survival and allows it to multiply in number. It particularly uses the Schwann cells of the brain, bind to it and damage the neurons. With this binding Schwann cell's ability to repair and regenerate the neurons is greatly affected. As a result the adverse effects show up.

On the skin it causes axonal dysfunction, damaging the signaling between cells and brain.

It also harms the myelin sheath that forms a protecting barrier for these nerves, as a result of this, loss of sensation arises. Dendritic cells (DCs) fight against infections to boost our immunity by activating other immune cells to eliminate the bacteria. In case of HD DCs engulf M. leprae but fail to activate itself and other cells, especially in early stages of infection. Only when the number of bacteria increases, do these cells start responding. Hence our immune system fails to fight against this threat and the infection further spreads in the body. Late activation of immune system does not help much.

Detection Now Made Easy Antibodies generated by the body to fight against M. Leprae can be detected through Enzyme linked Immunosorbent Assay (ELISA).

Slit Skin Smear- Biopsy sample from the lesions on the skin are subjected to staining by ZielNeelsen stain to detect the bacteria.

Visual inspection that shows red patches becomes an indicative parameter for diagnosing leprosy.

Warm and Cold Perception Involves testing threshold of temperature sensation on the skin. Tubes containing warm and cold water are touched to the skin and response to the change in temperature by the affected area on the body is analyzed.

Polymerase Chain Reaction (PCR)- A method that detects the genes of the bacteria. It is among the newer methods of testing and is considered as a confirmatory test.

End the Stigma, End the Disease! The cases of leprosy are now declining in India and also in the world, but still, a large number of patients in the country face social unrest and discrimination. It is contagious, but if efficient norms of care are followed, the spread can be stopped. This will also allow the focus to be diverted towards detection and treatment rather than the associated stigma.