Leprosy

LEPROSY

De Leoz, Maria Sabrina C.De Taza, Kaizette Mieje L

What is Leprosy?

A disease caused by the bacteria Mycobacterium Leprae, which causes damage to the skin and the peripheral nervous system. Chronic granulomatous disease, similar to tuberculosis,because it produces inflammatory nodules (granulomas) in the skin and nerves over time.

Leprosy develops slowly from 6months up to 40 yrs and results in skin lesions and deformities, most often affecting the cooler

places on the body (for example, eyes, nose, earlobes, hands, feet, and testicles) that can be very disfiguring. . Although human-to-

human transmission is the primary source of infection, three other species can carry and (rarely) transfer M. leprae to humans:

chimpanzees, mangabey monkeys, and nine-banded armadillos.

Etiology

In 1873, Dr. Hansen discovered bacteria in leprosy lesions, suggesting leprosy was an infectious disease, not a hereditary disease or a

punishment from the gods .First of all, and quite unexpectedly, the disease was more likely

introduced to West Africa by infected explorers, merchants or colonists from North Africa or Europe, rather than by migrants from East Africa.

Early humans probably left East Africa to settle in Western and Southern Africa 50,000 years ago, before humans arrived in the

Eurasian regions, and it seems improbable, according to the analysis conducted, that these first humans brought leprosy to West Africa. From West Africa, leprosy was then introduced to the Caribbean

islands, Brazil and probably to other regions of South America through the slave trade in the 18th century, as isolates with the same profile as

those from West Africa were discovered in these regions.

The strain of M. leprae is closer to the type present in Europe and North Africa, which indicates that colonialism and emigration from the Old Continent very clearly contributed to introducing

leprosy to the New World. In fact, in the 18th and 19th centuries, when Scandinavian immigrants settled in the western United

States, many cases of leprosy were reported, while a vast epidemic was simultaneously ravaging Norway. This hypothesis

is supported by the presence today of a strain with the same genetic profile as the strain from Europe and North Africa in

armadillos naturally infected in Louisiana (United States), which undoubtedly originated from human infection.

Signs and Symptoms

Early signs and symptoms of leprosy are very subtle and occur slowly (usually over years).

First symptoms : Numbness and loss of temperature sensation (cannot sense very hot or cold temperatures)

As the disease progresses : the sensations of touch, then pain, and eventually deep pressure are decreased or lost.

Long-term developing sequence of events : Relatively painless ulcers, skin lesions of hypopigmented macules (flat, pale areas of skin), and eye damage (dryness, reduced blinking) are experienced before the large ulcerations, loss of digits, and facial disfigurement develop that begins and continues on the cooler areas of the body (for example, hands, feet, face, and knees).

Mode of Transmission

Leprosy occurs more commonly in males than in females in most regions of the world. Leprosy is not particularly a disease of children as was once believed.

transmitted from person to person by aerosol with a high subclinical rate of infection. Casual contact does not cause leprosy. This contact may be direct (e.g. skin to skin) or indirect (e.g. contact with soil, and fomites such as contaminated clothes and linen).

may be transmitted by inoculation, such as by contaminated tattoo needles.

The nose is a major portal of exit of organisms of a person affected by leprosy. Some cases of leprosy harbor millions of Mycobacterium leprae in their nasal mucosa which are discharged when they sneeze or blow the nose.

The bacilli can also exit through ulcerated or broken skin of bacteriologically positive cases of leprosy.

Period of Communicability

Leprosy is not usually infectious after three months of continuous treatment with dapsone or clofazimine, or after two to three weeks of treatment with rifampicin.

At Carville in 1941, promin, a sulfone drug, showed efficacy but required many painful injections.

Dapsone pills were found to be effective in the 1950s, but soon (1960s-1970s), M. leprae developed resistance to dapsone. Fortunately, drug trials on the island of Malta in the 1970s showed that a three-drug combination (dapsone, rifampicin [Rifadin], and clofazimine [Lamprene]) was very effective in killing M. leprae. This multi-drug treatment (MDT) was recommended by the WHO in 1981 and remains, with minor changes, the therapy of choice. MDT, however, does not alter the damage done to an individual by M. leprae before MDT is started.

Susceptibility & resistance

Everyone is susceptible to infection, however study results have suggested a strong age-related susceptibility to being infected or developing disease following close contact with a multi-bacillary case. Children aged between five and nine years are at greatest risk. The risk of progression to leprosy disease following infection is considered to be approximately the same as tuberculosis which is approximately a 10% lifetime risk.

Susceptibility of Leprosy

• Symptoms and disease progression can differ from person to person depending on interactions between the affected person's immune system and the bacterium. The disease has been difficult to study in a laboratory setting, but evidence suggests that variation in disease susceptibility and symptoms are influenced mainly by human genetic variation.

Methods of Control

• Steps to control Leprosy:

1. Detection of cases of leprosy and tracing the contacts especially children of the patient's house.2. Prevention of contact between the patient and other normal persons, especially children.

3. Preventive treatment (chemoprophylaxis) with daps one.

4. Selective isolation or hospitalization of the patient showing acute reactions or complications.

5. Treatment of infected patients with daps one.

6. Rehabilitation of the patient with suitable work. Social and psychological rehabilitation is also necessary.

Programs for Prevention

• Leprosy Control Program: envisions to eliminate Leprosy as a human disease by 2020 and is committed to eliminate leprosy as a public health problem by attaining a national prevalence rate (PR) of less than 1 per 10,000 population by year

WHO gives an overview of leprosy and leprosy control activities around the world. ILEP Member Association support leprosy activities on a country-by-country basis throughout the world. In the USA, the Center for Disease Control(CDC) , gives general information about leprosy. The Report of the ILA technical forum, held in Paris in 2002, reviews much of the scientific evidence underpinning current efforts to control leprosy.

• Multi Drug-Therapy(MDT): a therapy introduced by WHO which consist of two regimens: rifampicin and dapsone for PB leprosy and rimfacin ,clozimine and dapsone for MB leprosy.

Prevention and Control

• Prevention of Leprosy for Household Contacts:

For prevention of leprosy, people who live in the same household as a person with leprosy (household contacts) will need to be examined by a physician. These examinations should be repeated annually for five years. It is important to note that the degree of natural immunity is high, and there is often no need for preventative medicine.

However, if you are a household contact and you develop a questionable skin rash, you should have a skin biopsy to determine whether or not leprosy is present.

• Tests and Vaccines for the Prevention of Leprosy

Although there is currently no vaccine available for the prevention of leprosy, researchers are actively working on developing one.

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