Leprosy: Causes, Transmission, Symptoms & Treatment

Table of Contents

What is Leprosy?

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, an acid-fast, rod-shaped bacillus.
Leprosy mainly affects the skin, the peripheral nerves, mucosa of the upper respiratory tract, and the eyes.
It is a chronic, progressive bacterial infection.
It is more prevalent in the tropical and subtropical areas.
Hansen’s disease is another name for leprosy.
Leprosy has existed for centuries of time. On every continent, people have been affected by its breakouts
World Leprosy Day is celebrated every year on the last Sunday of January.

Key Facts of Leprosy

Leprosy is a slow-moving chronic infectious disease caused by the bacillus Mycobacterium leprae.
It primarily affects the extremity nerves, the skin, the nasal lining, and the upper respiratory tract.
Multidrug therapy can be used to treat the condition.
Leprosy isn’t particularly contagious, and it’s most likely to spread by droplets from the nose and mouth during close, regular contact with untreated individuals.
It can cause serious disfigurement and substantial impairment, if not treated.
According to official estimates from 139 nations across six World Health Organization (WHO) regions, 127,558 new leprosy cases were discovered globally in 2020. Out of them, there were 8,629 children under the age of 15 years.
The new case detection rate among children was estimated to be 4.4 per million children.

Causes of Leprosy

Leprosy is caused by Mycobacterium leprae, a slow-growing bacteria (M. leprae)
Hansen’s disease is named after a Norwegian scientist, , who discovered leprae in 1873

Transmission

It’s unclear how Leprosy (Hansen’s disease) transmits from person to person
Leprosy is likely transmitted via droplets, from the nose and mouth, during close and frequent contact with untreated cases
Scientists believe it occurs when a person with leprosy (Hansen’s disease) coughs or sneezes and a healthy individual breaths in the droplets containing pathogen
It takes months of close contact with an untreated leprosy patient to contract the illness
Hansen’s disease cannot be conveyed from a mother to her unborn child during pregnancy, nor can it be transmitted through sexual contact
Identifying the source of infection can be difficult due to the bacteria’s slow growth rate and the time it takes for symptoms to manifest

Incubation Period

The incubation period of leprosy is 5 years on an average.
However, symptoms may appear within 1 years or as long as 20 years or more as well.

Signs and Symptoms

Discolored patches of skin that are usually flat, numb, and fading (lighter than the skin around)
Skin growths (nodules)
Thick, stiff, or dry skin
Painless ulcers on the soles of the feet
Swelling or lumps on the cheeks or earlobes that aren’t painful
Loss of brows or eyelashes
Numbness in the affected parts of the skin (especially in the hands and feet)
Enlarged nerves (particularly those around the elbow and knee, as well as those on the sides of the neck)
Blinding eye problems (when facial nerves are affected)

Types

The quantity and type of skin lesions determine the severity of leprosy. The type of leprosy determines the symptoms and treatment. The various types of leprosy are:

1. Tuberculoid

Leprosy that is milder and less severe.
This variety has only one or a few flat, pale-colored patches on its skin (paucibacillary leprosy)
Because of nerve injury beneath the skin, the affected area may feel numb.
Tuberculoid is less contagious than other types of leprosy.

2. Lepromatous

An advanced stage of the disease
It causes extensive skin lumps and rashes, numbness, and muscle weakness (multibacillary leprosy)
The nose, kidneys, and male reproductive systems may also be affected.
It is more infectious than tuberculosis.

3. Borderline

Its symptoms are similar to both tuberculoid and lepromatous leprosy.

Doctors may also use the following classification:

Single lesion paucibacillary (SLPB): One lesion
Paucibacillary (PB): Two to five lesions
Multibacillary (MB): Six or more lesions

Diagnosis

Physical examination to look for signs and symptoms of disease
Biopsy
Lepromin skin test: to determine the type of leprosy

Treatment of Leprosy

In 1995, the World Health Organization (WHO) devised a multidrug medication to treat all kinds of leprosy (Hansen’s disease). It’s available for free all over the world.
Several antibiotics are also used to treat Hansen’s disease by destroying the bacterium that causes it.
These antibiotics are dapsone (Aczone), rifampin (Rifadin), clofazimine (Lamprene), minocycline (Minocin), and ofloxacin (Ocuflux)
Anti-inflammatory drug such as aspirin (Bayer), prednisone (Rayos), or thalidomide (Thalidomide) (Thalomid).
The treatment will persist for months, with the possibility of lasting up to two years.

Consequences of Leprosy

Muscle weakness
Nerve damage in the arms and legs which is permanent
Inability to use hands and feet
Chronic nasal congestion, nosebleeds, and collapse of the nasal septum
Iritis
Glaucoma
Blindness
Erectile dysfunction
Infertility
Kidney failure

Preventive Measures

Immunoprophylaxis
Good coverage of BCG vaccine
Chemoprophylaxis of chronic infectious diseases
Education and awareness among the people
Avoiding long-term, close contact with an untreated person who has leprosy (Hansen’s disease) is also the greatest way to prevent it.
However, in case if a person is affected with leprosy, early diagnosis and prompt treatment is the best way to prevent the spread of leprosy.

WHO Response

WHO published ‘WHO guidelines for the diagnosis, treatment, and prevention of leprosy 2018’ in, which recommended a three-drug regimen (rifampicin, dapsone, and clofazimine) for both paucibacillary and multibacillary varieties of leprosy.
In April 2021, WHO announced ‘Towards Zero Leprosy – Global Leprosy (Hansen’s disease) Strategy 2021-2030’ in line with NTD road plan 2030, following extensive consultations with countries, specialists in leprosy, partners, and people affected by leprosy.

Strategic Pillars Set by WHO to Eliminate Leprosy

In all endemic nations, implement coordinated, country-owned zero leprosy roadmaps.
Increase leprosy prevention while also incorporating active case detection.
Manage leprosy and its complications, as well as the risk of new disabilities.
Defeat stigma and ensure that human rights are upheld
For this strategic phase, the strategy comprises a set of core research priorities. To eradicate leprosy, global and national research investments are also required
WHO issued a technical guide on Leprosy/Hansen Disease treatment of responses/prevention of disabilities in 2020 to provide hands-on information to health workers on how to diagnose and manage Lepra reactions early
In 2020, the World Health Organization published a technical guidance on Leprosy Hansen disease contact tracing and post-exposure prophylaxis.
WHO has created e-learning modules to help professionals at all levels improve their knowledge and skills on issues ranging from suspected referrals and diagnosis through leprosy treatment and disability management