Leprosy is a lasting mycobacterial disease instigated by Mycobacterium leprae. It is one of the ancient disease and is still afflicting many patients in different parts of the world. Prevalence is higher in Asia and Africa. It is one of the debilitating disease infecting nervous system, skin, eyes, testes, etc. this disease cause extreme morbidity to the patent. Often patients are separated from the general population to avoid the spread of the disease.
Mycobacterium leprae is a slender, slightly curved bacteria causing leprosy. It is a chronic granulomatous disease of humans and the only source of infection is patient. The bacteria localise primarily in the skin, peripheral nerves & nasal mucosa but may involve other organ as well. This bacteria prefer cooler temperatures and hence has more predilection to affect the cooler tissues or low temperature areas of the body. Incubation period of the bacteria is very long and variable.
3MEDS-online medical store in India, briefs about the leprosy disease,
Sources of infection:
The main sources of transmission is via nasal discharge and skin lesions of the patients. It requires close contact of the individual with the affected patient to acquire the disease. Leprosy is related to the immune status of the host.
There are four forms of leprosy namely, lepromatous, tuberculoid, dimorphous, and intermediate. The lepromatous and tuberculoid are two extreme forms of leprosy. The intermediate type occupies a position between these two extreme forms.
Signs and symptoms:
Lepromatous type:
· Affected individual develops nodular skin lesions (lepromata) on face, ear lobes, hands, feet, & less commonly on trunk.
· Thickening of peripheral nerves over a period.
· Numbness.
· Loss of sensation results in ulceration of nodular lesions due to repeated trauma.
· The ulcerated nodules get secondarily infected which leads to alteration & mutilation of extremities.
· Skin lesions contain many macrophages packed with bacilli which are present in large number in mucosa of nose, mouth & upper respiratory tract.
Tuberculoid type:
· Skin lesions are few, consisting of non-elevated hypo or hyper-pigmented macular patches involving the face, limbs and trunk.
· Thickening of local peripheral nerves are involved in the early stage & gradually extends into bigger nerve trunks which later become hard and tender. This may lead to deformities of hand and feet.
Oral lesions develop on the tongue, lip or hard palate. These lesions consist of small tumour like masses called lepromas. These over a period tend to ulcerate. In the facial regions, skeletal changes such as atrophy of anterior nasal spine, saddle nose & premaxillary bone recession with or without tooth loss.
Immunity and infection:
Only a minority of the human population develops this disease. Due to existence of a high degree of innate immunity, only few contacts develop the disease. Mycobacterium leprae affects both types of immunity i.e. humoral & cell mediated immunity. Patients with deficient cell mediated immunity develop lepromatous type of disease, and when cell mediated immunity is adequate, the lesions are of tuberculoid type.
Diagnosis:
Specimens are taken from the nasal mucosa, skin lesions and ear lobules. From skin, specimen is obtained by slit and scrape method. Smears from the nose are made by scraping a little material from the nasal septum with a small blade knife.
Acid-fast staining of the specimen is done by Ziehl-Neelsen stain. Acid-fast bacilli organized in parallel bundles within macrophages confirm the diagnosis of lepromatous leprosy. The viable bacteria are fragmented, irregular or granular.
Skin and nerve biopsy:
These are required for histological confirmation of tuberculoid leprosy and for diagnosis and accurate classification of the leprosy lesion
Lepromin test;
It is a test of delayed hypersensitive reaction. Used for classification of leprosy, assessment of prognosis and assessment of resistance.
Serological test:
Serodiagnosis of leprosy may be carried out by detection of anti PGL-1 antibodies. Various tests like latex agglutination, MLPA & ELISA have been described.
Treatment:
Dapsone was the standard treatment earlier. However, due to the emergence of Dapsone resistance, WHO recommended multi drug therapy for all leprosy cases. Drugs like rifampicin 600 mg once a month and dapsone 100 mg daily for six months is for paucibacillary leprosy.
For multibacillary leprosy, rifampicin 600 mg once a month, dapsone 100 mg daily, clofazimine 50 mg once a month (supervised), and 50 mg clofazimine daily (unsupervised) are given for one year.
Outlook:
Even though the disease is highly communicable, there is innate resistance to avoid the disease in majority of the population. Preventive measures such as early diagnosis & treatment, surveillance of contacts, health education, and vaccination can keep the disease at bay. There is no confirmed vaccine, however BCG is believed to confer little immunity. All the medications recommended for the treatment can be ordered online from 3MEDS-best medicine app in India.