What is Leprosy?
Today, the diagnosis and treatment of leprosy is extremely easy, but it wasn’t always so. Leprosy or Hansen’s disease, which has been around since ancient times, struck terror in the ancient civilizations and it was only in the past century that we came to have a better understanding of the disease. Leprosy is infectious and causes disfiguring sores and nerve damage, making the symptoms quite disturbing to anyone who does not know how the disease is spread and progresses. Modern treatments have brought the disease under control and numbers are declining in most parts, including in regions where the disease is endemic.
What are the Symptoms of Leprosy?
Leprosy symptoms do not surface as soon as a person is infected and they usually develop only 3 to 5 years after exposure to the bacteria. In some cases, the symptoms may even surface 20 years after the infection has occurred! This makes determining the source or time of infection difficult, but diagnosis of leprosy is not very tricky because of the undeniable symptoms. Diagnostic tests may be recommended to ascertain suspicions. Leprosy symptoms include:
- Faded and discolored patches or lesions
- Thickening, dryness or stiffness of certain areas of skin
- Loss of sensation in the affected area
- Muscle weakness in the extremities and possible paralysis because of nerve damage
- Vision problems and possible blindness
- Bleeding of the nose and nasal congestion
- Ulceration on the feet
The risk of bodily injuries is possibly more threatening than the disease itself as burns, fractures and other injuries may even go unnoticed because of the loss of sensation.
What causes Leprosy?
Leprosy is caused by the Mycobacterium leprae, which is a slow growing bacterium. The disease is infectious, but it is not highly contagious and most of the stigma associated with the condition is based on misconceptions and fear as a result of a lack of knowledge. The condition can only be spread through prolonged contact with an infected person and the risk is much higher for children. The bacteria responsible for leprosy were only identified in 1873 by a scientist Hansen, lending the disease its other name “Hansen’s Disease”.
Although leprosy does not pose a grave public threat it is endemic to certain parts of the world and there is still a lack of awareness about the disease. To better address the spread of infection and contain and treat the disease it is important for us to have a better understanding of certain facts about leprosy.
History of Leprosy
- There is a rich body of literature on the history of leprosy, with ancient texts mentioning symptoms suggestive of the disease from as far back as 4000 BC. The condition is known to have existed in ancient India, China, Israel and Egypt.
- Leprosy was much feared in antiquity and medieval times because of the lack of knowledge about the disease. In the absence of any effective treatments, lepers were shunned and ostracized, being forced to live as outcasts in ‘leper societies’.
- Lepers living in Medieval Europe had to make the presence known by carrying a bell around with them.
- M. leprae was in fact the first identified disease causing bacteria in humans and the discovery is credited to G. H. Armauer Hansen in the year 1873.
- Promin, which was the first effective treatment for leprosy, only became available over half a century later in the 1940s.
- Indian scientist Shantaram Yawalkar was also instrumental in the fight against leprosy. He formulated a combination therapy that used both rifampicin and dapsone, in an effort to control bacterial resistance.
- Multidrug therapy (MTD) was only introduced in the 1980s and the disease was finally brought under control.
The World Health Organization’s goal of reducing and eliminating the disease is progressing successfully. WHO’s Enhanced Global Strategy for Further Reducing Disease Burden Due to Leprosy emphasizes the importance of detection and treatment with MDT. According to WHO statistics:
- 189,018 cases of leprosy were recorded as being prevalent towards the end of 2012. In the same year, there were 232,857 new cases against the 226,626 recorded in 2011. This data was compiled from reports from 115 countries.
- Elimination of the disease is defined by a prevalence rate of less than 1 case per 10,000 people at a global level. This goal was achieved in 2000. It is estimated that some 16 million patients have been cured of the disease through the use of MDT over the past 2 decades.
- Leprosy is still endemic in few countries, but the disease has declined globally. 95 percent of all new cases were reported from within 16 countries while the rest of the world just accounted for 5 percent.
- 54 percent of all new cases of leprosy were reported from India.
- There are actually two types of leprosy. Tuberculoid and lepromatous leprosy are the two forms and both cause the appearance of skin sores, but lepromatous is a lot more severe, causing the appearance of large bumps and lumps.
- While naturally occurring infection is reported in some primates and other species it can only be transmitted from armadillos, but this is also extremely rare.
- Leprosy is not very infectious when the patient receives treatment and there is almost no risk of infection within just 2 weeks of treatment.
- In regions where the disease is endemic, as is the case in India, as much as 95 percent of the population is naturally immune to the infection, making the disease far less threatening in terms of contagion.
- Drug resistant varieties of the Mycobacterium leprae have become a cause for concern however as this has contributed to an increase in leprosy cases.
- There has been a 90 percent decline in the prevalence of leprosy by 2000, with just 1 infected person per 10,000 as compared to the prevalence rate of 21.1 per 10,000 prior to the enforcement of WHO’s global strategy.
- In 1985 there were 5.2 million people afflicted with the disease. Despite the fact that global population has risen from under 5 billion at the time to over 7 billion today, there were just 189,018 recorded cases in 2012. The decline began in the late 80s itself with the numbers of infected falling from 5.2 million to just 805,000 in a span of 10 years.
- In 1985 the disease was regarded as a public health problem in 122 countries. It has been eliminated from 119 of these countries.
- Global leprosy situation, 2012. Wkly Epidemiol Rec. 2012 Aug 24;87(34):317-28. English, French. PubMed PMID: 22919737.
- "Leprosy: global situation." WHO. from - (http://www.who.int/lep/situation/en/ accessed on 28 January 2015.)
- "Leprosy Fact Sheet." WHO. from - (http://www.who.int/mediacentre/factsheets/fs101/en/ accessed on 28 January 2015.)