Leprosy is a chronic infection that mainly affects peripheral nerves, skin, eyes, and the upper respiratory tract. It is caused by a slow multiplying bacillus, which determines its lengthy incubation period: five years on average, although symptoms may appear after as much as 20 years after the bacillus is contacted (“Leprosy Fact Sheet”). The formation of granulomas on the nerves leads to a partial loss of the ability to feel pain. Due to this, people affected with leprosy often fail to notice injuries and treat them properly. Thus, such injuries may cause severe damage, sometimes leading to the loss of extremities. Understanding leprosy as a disease requires considering its symptoms, transmission, causes, treatment, and distribution.
The primary and most observable signs of leprosy appear on the skin. Over 70 percent of surveyed people affected with leprosy experienced skin lesions, namely white or dark patches. The patches were not painful or itchy. Further symptoms are numbness and decreased sensitivity to pain (Singh et al. 72). Leprosy is usually perceived as a disease that causes grave disfigurement. In mass perception, a leper is a person with the decaying flesh and limbs falling off. However, the disease itself does not lead to such deformities. They are mostly caused by secondary diseases or injuries that are not detected in proper time and subsequently poorly treated due to the anesthesia (Singh et al. 72). Thus, the disfigurement associated with leprosy is not a direct effect of the disease, but an indirect one, occurring due to the weakening of the defense mechanisms of a body. Other symptoms of leprosy may include the loss of muscle strength, the loss of sweating, and the worsening of sight (Nunzi and Massone 182). People affected with leprosy may report weakness, as well as runny nose, the unusual coloring of the skin, and even change of voice like nasality due to the infection processes in the nasal area.
Although lepers were feared and driven into isolation in many societies, it is now proven that leprosy is not a highly contagious disease (“Leprosy Fact Sheet”). To be infected by leprosy means to have the bacillus from the body of a person affected with leprosy enter your body. There are two recognized exit routes: nasal mucosa and skin. Nasal droplets are the main media for leprosy transmission. Some bacilli may be contacted through the skin as well, although this threat is much lesser (Thomas). The skin, however, may act as an entry route. Another entry route is airways. Despite this knowledge, the popular perception of leprosy transmission features a much wider variety of ways to get infected. Almost 70 percent of surveyed people affected with leprosy claimed to believe that they had been infected through sharing food or drinks with a leper (Singh et al. 71). Other reported assumptions of how leprosy can be transmitted included sharing utensils, contacting the leper’s skin and sweat, having sexual encounters, and even being bitten by mosquitoes or other insects. Present-day scientific data do not confirm these assumptions, but neither do they refute them completely. According to Nunzi and Massone, “the exact route of transmission of [the bacillus that causes leprosy] remains obscure” (6), but it is emphasized that research in this area is crucial for early detection, efficient treatment, and prevention of the disease distribution.
Leprosy is caused by a bacterium called Mycobacterium leprae. It is an obligate intracellular parasite, meaning that it lives inside the cells of a host organism and can only reproduce within those cells by using intracellular resources. The bacterium is pathogenic, acid-fast, and aerobic, which means that it causes infection, is relatively easy to detect chemically and requires oxygen for growth (Ryan and Ray 492). Despite the bacterial nature of this disease, among respondents affected with leprosy in Chandigarh, India, only a few (about 15 percent) believed that a bacterium could act as the causative agent of leprosy. Some people regarded their sins and vices as the reason for getting the disease. The most widespread belief was that the cause was a skin-to-skin contact with a leper (Singh et al. 73). This belief comes from the conspicuity of leprosy signs on the skin. Risk factors of being infected by leprosy are not clearly identified. However, it is understood that a weakened immune system may be one such factor. An immune system can be undermined by poor living conditions, current illness, malnutrition, etc. Since leprosy is not highly contagious and requires close contact for transmission, epidemics of leprosy are relatively rare, although they can occur due to poor sanitation in densely populated areas.
Leprosy was considered to be an incurable disease, but the understanding of its bacterial nature and the development of medicine allow treating it successfully nowadays and attaining full recovery. The main point of leprosy treatment is to kill the bacteria. The main treatment method is multidrug therapy (MDT). The introduction of MDT in the early 1980s by the World Health Organization (WHO) was the most significant event in the long history of combating leprosy (Kar and Gupta 58). The necessity to apply several types of drugs to the treatment of leprosy is explained by the high possibility of the presence of resistant mutants among causative bacteria in leprosy patients. The drugs should be selected with the consideration to optimally combine their effects so that the effects of some of them compensate for the effects of others. It is possible if the drugs have different mechanisms of action (Kar and Gupta 58). Although the WHO MDT method is still appreciated by the medical community, there are new drugs and new combinations of drugs proposed recently that have proven to be effective. Particularly important drugs in leprosy treatment today are dapsone, rifampicin, clofazimine, and fluoroquinolones (Kar and Gupta). The killing of the bacteria takes three to six months, while full clinical regression takes two to three years (Kar and Gupta 56). However, additional or further treatment may be needed in case of serious deformities (Thomas par. 13). This includes surgeries and rehabilitation.
Different societies faced leprosy throughout almost the entire human history. Although there is significant progress today in terms of treatment and prevention, leprosy is still a problem. It is now known that 95 percent of people worldwide are naturally immune to leprosy (Thomas par. 1). However, within recent years, over 200,000 new cases of leprosy are reported annually (“Leprosy Fact Sheet”). Epidemiologic data suggest that the countries with the largest amounts of people affected with leprosy are India, Brazil, and Indonesia. The number of reported leprosy cases has been decreasing yearly within recent decades. However, in particular regions, like South America and South Asia, the disease is still daunting. The risk conditions include poor sanitation, lack of access to clean water, and poor bedding. The heat may also be a risk factor. Hot regions are more favorable environments for infections overall. Also, in hot regions, it is harder to preserve food and prevent or control the distribution of bacteria.
Leprosy is a disease with a long history. People affected with leprosy (previously referred to as lepers, which is now considered by some a pejorative term, although it is still occasionally used today) would be driven into isolated colonies. The way this disease sometimes disfigures a body was the reason for the widespread fear of lepers. Within recent decades, humanity has made significant progress in treating the disease as well as discarding many myths associated with it. With modern medical knowledge and technology, there is a hope that leprosy will be defeated completely in the future.
List of Terms and Definitions
Acid-fast means resistant to decolorization after being stained. The term comes from the fact that such decolorization is normally caused by mineral acids.
Aerobic organisms need oxygen to live and grow.
Anesthesia is the use of special substances to deprive an organism of the ability to feel pain in particular parts of the body or in the entire body. The term anesthesia can also refer to the loss of the ability to feel pain due to a disease like leprosy.
Bacterial infection is an infection cause by bacteria. Other infections may be caused by fungi or viruses.
Bacterium is a unicellular microorganism.
Chronic infection is a long-term infection. Unlike an acute infection, it lasts for a long period of time.
Clofazimine is a drug of the bacteriostatic and anti-inflammatory action, which means it prevents the growth and reproduction of bacteria and reduces the inflammation processes.
Dapsone is a drug that inhibits the biosynthesis of bacteria, i.e. the generation of complex molecules within them.
Entry route, in the context of infections, is a region of the body, through which an infection gets into the organism
Epidemiology is the study of how diseases occur, distribute, and transform within populations.
Exit route, in the context of infections, is a region of the body of an infected person, through which an infection can be transmitted to other people.
Fluoroquinolones is a drug that inhibits the coiling and super-coiling of bacterial DNA.
Granuloma is a tumor that appears in response to an infection.
Immune system is a mechanism within organisms that allows these organisms resist infections and toxins. “Immunity” may also refer to the natural inability to get a particular disease (e.g. genetic immunity).
Incubation period of an infection is a period of time between the causative organism is contacted and the first symptoms appear.
Infection is a disease caused by germs or bacteria.
Multidrug therapy (MDT) is a method of treatment that employs a series of drugs to be taken by a patient within the same period of time.
Mutant is an organism with genetic modifications that make it physically different from the majority of other members of its species.
Obligate intracellular parasite is a parasite (i.e. an organism that feeds on the nutrients from a different organism and lives on or inside its host) that lives within a cell and requires resources from inside the cell. Such parasites cannot live outside of cells.
Pathogenic refers to something that causes a disease.
Peripheral nerves are nerves (i.e. fibers consisting of neurons that transmit messages within organisms) outside of the central nervous system, that is, outside the brain and the spinal cord.
Rifampicin is a bactericide, i.e. a substance that kills bacteria.
Risk factor, in the context of medicine and epidemiology, is a condition or circumstance that increases the risk of getting a particular disease.
Skin lesion is a wound on the skin.
Slow multiplying bacillus is a rod-shaped bacterium (long and narrow) that requires a long time to reproduce and spread.
References
Kar, Hemanta Kumar, and Ruchi Gupta. “Treatment of Leprosy.” Clinics in Dermatology 33.1 (2015): 55-65. Print.
Leprosy Fact Sheet 2016. Web.
Nunzi, Enrico, and Cesare Massone. Leprosy: A Practical Guide. Milan: Springer, 2012. Print.
Ryan, Kenneth J., and C. G. Ray. Sherris Medical Microbiology. New York: McGraw-Hill Education/Medical, 2014. Print.
Singh, Sukhbir, Anil K. Sinha , BG. Banerjee, and Nidhi Jaswal. “Knowledge, Beliefs and Perception of Leprosy.” Disability, CBR & Inclusive Development 23.4 (2013): 67-75. Print.
Thomas, Liji. What is Leprosy? Web.