Disease leprosy causes. What is leprosy, causes, symptoms and modern treatments for leprosy. Geographic distribution and frequency

Epidemiology

Distribution of leprosy in the world (2003).

Leprosy is transmitted through discharge from the nose and mouth, during close and frequent contact with people who are not being treated.

During the 1990s, the number of patients with leprosy in the world decreased from 10-12 million to 1.8 million. Leprosy is mainly distributed in tropical countries. But although the number of cases in the world continues to fall, the disease is still widespread in parts of Brazil, South Asia (India, Nepal), East Africa (Tanzania, Madagascar, Mozambique) and the Western Pacific. Brazil ranks first, India second and Burma third. In 2000, WHO listed 91 countries with endemic foci of leprosy. India, Burma and Nepal together accounted for 70% of cases.

The high-risk group includes residents of areas of endemic prevalence of leprosy with poor living conditions: polluted water, without bedding and adequate food. Individuals suffering from diseases that weaken immune function (such as AIDS) are also at high risk.

In 1995, WHO estimated the number of people disabled by leprosy at 2 million.

In 1999, the number of patients with leprosy in the world was estimated at 640 thousand people, in 2000 - 738,284 people, in 2002 - 763,917 people.

At the beginning of 2009, according to official WHO data, there were 213,036 people infected with leprosy in the world.

Incubation period

The incubation period is usually three to five years, but can range from six months to several decades (an incubation period of 40 years has been described). It is asymptomatic. Also, leprosy is characterized by an equally long latent period, non-specificity and optional prodromal signs (malaise, weakness, drowsiness, paresthesia, feeling of chilliness), which greatly complicates the early diagnosis of the disease.

Types of disease

Basically, leprosy affects the air-cooled tissues of the body: the skin, the mucous membrane of the upper respiratory tract, and superficial nerves. In untreated cases, infiltration of the skin and destruction of the nerves can lead to severe deformity and deformity. However, mycobacterium leprosy itself is not capable of causing the death of fingers or toes. Secondary bacterial infection results in the loss of body parts through tissue necrosis when numb tissues are injured and go unnoticed and untreated. There are two polar types of the disease (tuberculoid and lepromatous), borderline and indeterminate. Leprosy indefinite usually begins with a skin lesion. The foci are almost invisible. The first symptom is usually paresthesia or hyperesthesia in some area of ​​the skin. On closer examination, one or more hypo- or hyperpigmented spots can be found here. The rash may resolve on its own in one to two years.

tuberculoid leprosy

Tuberculoid leprosy usually begins with a well-defined, hypopigmented patch, within which there is hyperesthesia. In the future, the spot increases, its edges rise, become roller-shaped with an annular or spiral pattern. The central part of the spot undergoes atrophy and sinks. Within this focus, the skin is devoid of sensitivity, there are no sweat glands and hair follicles. Near the spot, thickened nerves innervating the affected areas are usually palpated. Damage to the nerves leads to muscle atrophy; hand muscles are especially affected. Contractures of the hands and feet are not uncommon. Injuries and compression lead to infection of the hands and feet, neurotrophic ulcers form on the soles. In the future, mutilation of the phalanges is possible. With damage to the facial nerve, lagophthalmos and the resulting keratitis occur, as well as a corneal ulcer, leading to blindness.

Lepromatous leprosy

Lepromatous leprosy is usually accompanied by extensive and symmetrical skin lesions relative to the midline of the body. Lesions can be represented by spots, plaques, papules, nodes (lepromas). They have vague borders, a dense and convex center. The skin between the elements is thickened. The most commonly affected areas are the face, ears, wrists, elbows, buttocks, and knees. A characteristic feature is the loss of the outer third of the eyebrows. The later stages of the disease are characterized by a "lion's face" (distortion of facial features and a violation of facial expressions due to thickening of the skin), proliferation of earlobes. The first symptoms of the disease are often nasal congestion, nosebleeds, and difficulty breathing. Possible complete obstruction of the nasal passages, laryngitis, hoarseness. Perforation of the nasal septum and deformity of the cartilages lead to retraction of the back of the nose (saddle nose). The penetration of the pathogen into the anterior chamber of the eye leads to keratitis and iridocyclitis. Inguinal and axillary lymph nodes are enlarged, but not painful. In men, infiltration and sclerosis of the testicular tissue lead to infertility. Gynecomastia often develops. Late stages of the disease are characterized by hypoesthesia of the peripheral extremities. Skin biopsy reveals diffuse granulomatous inflammation.

The borderline types of leprosy in their manifestations stand between the polar types.

Treatment of leprosy

The treatment of leprosy requires the participation of many specialists. In addition to antimicrobial therapy, consultations and treatment by an orthopedist, ophthalmologist, neuropathologist, physiotherapist may be needed. Antileprosy therapy is carried out using the following means: dapsone, rifampicin, clofazimine; Recently, the antileprosy activity of minocycline, ofloxacin, and clarithromycin has been discovered.

Forecast

With timely diagnosis, leprosy is completely curable. With belated treatment, the disease leads to persistent morphological changes and disability of the patient.

famous sick people

LEPROSY
(leprosy), a chronic infectious disease that usually affects the skin and peripheral nerves. Contrary to prejudice, leprosy is not transmitted by the mere touch of a sick person and is not always fatal. Only 5 to 10% of people at risk of contracting leprosy actually get it, since most people have a sufficient level of immunological protection against the pathogen, and in addition, its pathogenicity, i.e. the ability to cause disease is relatively low. It has long been known among physicians that the spread of leprosy occurs as a result of prolonged direct skin contact. However, many modern researchers believe that infection is also possible by inhalation of bacteria that enter the air from the patient's nose or mouth. Two main types of leprosy are known: lepromatous, affecting mainly the skin, and tuberculoid, affecting mainly the nerves. There are also erased and borderline forms of the disease, but they can be considered intermediate, tending to develop in any of the two main types.
Geographic distribution and frequency. At present, leprosy occurs mainly in the tropics and subtropics; it is rare in colder climates. The disease is common in Africa and Asia (especially in India), in Spain and Portugal, in the countries of the former USSR and Korea, in Japan and the Philippines, as well as in Central and South America. In the US, people with leprosy are found along the Gulf Coast, Southern California, and Hawaii. Leprosy is not a mass disease, but according to WHO data, about 11 million people in the world suffer from it, among which there are three times more men than women. Children are more susceptible to leprosy than adults.
Pathogen. Leprosy is caused by rod-shaped organisms Mycobacterium leprae, discovered in 1874 by G. Hansen. The incubation period from infection to manifestation of the disease can last from 2 to 20 years, but in most cases the first symptoms appear after 3-10 years. Leprosy mycobacteria are close in their properties to tuberculosis, but are incapable of growth on artificial nutrient media, which made it difficult to study leprosy. In 1957, Ch. Shepard was the first to cultivate them in the paw pads of laboratory mice. In 1971, the armadillo Dasypus novemcinctus was found to be susceptible to infection with leprosy and was used to obtain large quantities of Mycobacterium leprosy for experimental purposes.
Symptoms. Basically, leprosy affects the air-cooled tissues of the body: the skin, the mucous membrane of the upper respiratory tract, and superficial nerves. In untreated cases, infiltration of the skin and destruction of the nerves can lead to severe deformity and deformity. However, mycobacterium leprosy itself is not capable of causing the death of fingers or toes. Secondary bacterial infection results in the loss of body parts through tissue necrosis when numb tissues are injured and go unnoticed and untreated. Of the two types of leprosy, lepromatous is more severe. Mycobacteria thrive in the skin, causing nodules called lepromas and sometimes scaly plaques. Gradually, the skin thickens, large folds form, especially on the face, which becomes similar to a lion's muzzle. With tuberculoid leprosy, flat, scaly patches of a reddish or whitish hue appear on the skin; in places of damage, there is a thickening of the sheaths of the nerves, which, progressing, leads to a local loss of sensitivity. Damage to large nerve trunks can result in destruction of bones and joints, which is usually limited to the limbs. With leprosy of the tuberculoid type, a spontaneous cure is possible.
Treatment. Sulfone preparations have replaced haulmoogra oil, which has been used for centuries in the treatment of leprosy. The therapeutic effect of sulfones is manifested only after prolonged use. They cannot be attributed to specific remedies, but in most cases they are able to stop the development of leprosy. In mild cases, the patient may recover as a result of two years of therapy, but in severe cases, it may take at least eight years to cure. However, in the early 1980s, strains of Mycobacterium leprosy were noted to be resistant to dapsone (diaphenylsulfone), which had been the main treatment for leprosy since the 1950s. Therefore, now it is often used in combination with other drugs. In the lepromatous type of the disease, clofazimine is also widely used.
Prevention. There is currently no way to prevent leprosy. However, promising research is under way to improve a vaccine containing killed Mycobacterium leprosy; its effectiveness has been shown in experiments on mice and armadillos.
Story. Leprosy is generally believed to be one of the oldest diseases. It is mentioned in the Old Testament, but most modern scholars believe that in biblical times, leprosy was called a whole range of skin diseases that made the patient "unclean." In the Middle Ages, those suffering not only from leprosy, but also from many other diseases, such as syphilis, were referred to as "unclean". 12th to 14th centuries the incidence of leprosy reached its peak in Europe, then began to fall rapidly and by the end of the 16th century. disappeared in most European countries, with the exception of the Mediterranean coast, a number of regions of Russia and Scandinavia. The first colonists from Spain, Portugal and France brought leprosy to America. A new rise in the incidence was caused by the African-American slave trade, which led to the introduction of leprosy in parts of the Western Hemisphere.

Collier Encyclopedia. - Open Society. 2000 .

See what "LEprosy" is in other dictionaries:

See the prank to build pranks ... Dictionary of Russian synonyms and expressions similar in meaning. under. ed. N. Abramova, M .: Russian dictionaries, 1999. leprosy trick, toys, pampering, leprosy, tomfoolery, prank, game, mischief, mischief, leonthiosis ... ... Synonym dictionary

Female lepra, a hereditary and possibly contagious skin disease, lepra, which is much spoken of in the Holy Scriptures. At that time, it looked like malignant lichen, turning into purulent ulcers, partly still known to ... ... Dahl's Explanatory Dictionary

1. Leprosy, s; and. Prank, trick. Children's, boyish p. To make fun of the pranks of clowns. 2. LEprosy, s; and. Severe chronic human infectious disease, accompanied by damage to the skin, muscles, larynx, internal organs; leprosy. * … encyclopedic Dictionary

leprosy- LEprosy, spec. leprosy ... Dictionary-thesaurus of synonyms of Russian speech

leprosy, the same as leprosy ... Modern Encyclopedia

Same as leprosy... Big Encyclopedic Dictionary

- (disease), see LEPROA ... Scientific and technical encyclopedic dictionary

Explanatory Dictionary of Ushakov

1. Leprosy1, leprosy, pl. no, female Skin chronic contagious disease, considered incurable. Patients with leprosy are kept in leper colonies. 2. LEPROZA2, leprosy, fem. Prank, trick. Children's leprosy. "All from your pranks!" Griboyedov. "I've been long... ... Explanatory Dictionary of Ushakov

Leprosy 1, s, f. A chronic infectious disease that affects the skin, eyes, nervous system, and some internal organs. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov

Leprosy 2, s, f. Same as prank. Children's leprosy. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov

Books

• Boileau-Narsejac. A set of 10 books, Boileau-Narsejak, For the first time in Russian - all novels, short stories and collections of stories by P. Boileau and T. Narsejak, French writers - co-authors, world-famous masters of the detective genre - in full ... Series: French Detective's Library Publisher:

Few diseases have such a dismal reputation as leprosy. Firstly, it disfigures people not only severely, but also in a very diverse way, often causing an aesthetic shock. Second, before the invention of specific chemotherapy in 1943, leprosy was virtually incurable. Third, the causes of leprosy have long been mysterious. This disease is specially invented to give the impression of an unpredictable "punishment of the Lord": it affects people very selectively and, moreover, has a huge incubation period. Until the end of the 19th century, there were serious discussions among physicians about whether leprosy was contagious at all and whether it was caused, for example, by eating fish.

The Greek word "leprosy" (λέπρα), denoting leprosy, entered scientific circulation in the 3rd century BC, after the famous seventy interpreters in Alexandria of Egypt translated the Old Testament into Greek. But, of course, this disease was known to people before. It allows some countries to forget about itself for a long time, in others it roams. At the beginning of the 20th century, on the eastern outskirts of the Belgian Congo, there was a rather extended area where 20% of the population, that is, every fifth ( Transactions of the Royal Society of Tropical Medicine and Hygiene, 1923, 16, 8, 440-464). And in West Africa (French Guinea), at one time there was an area where even 32% were affected - every third ( Annales de médecine et de pharmacie coloniales, 1920, 18, 109–137). These figures are hard to believe, but they are in the literature.

Leprosy is a complex phenomenon. It can be the object of study of various sciences, from molecular biology to cultural studies - just remember such books as "The Name of the Rose" by Umberto Eco or "The History of Madness in the Classical Age" by Michel Foucault.

However, knowing that we live in an evolving world, it is natural to ask the following question: where did leprosy come from? Or, more precisely, where and when did it originate?

Genomics and deduction

"On the origin of leprosy" is the title of an article published in 2005 by an international group of microbiologists and geneticists led by Mark Monod of the famous Pasteur Institute in Paris ( Science, 2005, 308, 5724, 1040–1042). The causative agent of leprosy is an immobile bacterium, close to tubercle bacillus (they belong to the same genus). In Latin, this bacterium is called Mycobacterium leprae. It was discovered by the Norwegian Gerhard Hansen and the German Albert Neisser back in the 70s of the XIX century. And by the beginning of the 21st century, it was studied well enough to try to solve the question of the origin of leprosy using comparative genomics. That's what the group Mono and undertook.

The genome of the causative agent of leprosy was first completely read in 2001. It is quite small, even by the standards of bacterial genomes, which are always small. This genome has undoubtedly undergone evolution in the direction of simplification: it is not for nothing that a significant part of the genes in it turned into pseudogenes (the so-called non-functional former genes that survived, but lost the ability to any activity). In addition, comparison of different populations M. leprae shows that the intraspecific variability of its genome is very low, it is exceptionally stable in space and time. Finding variable regions in such a genome, on the basis of comparisons of which at least some evolutionary conclusions can be drawn, turned out to be not so easy.

Realizing this, Monod's group focused on the most elementary components of genetic variability: on single-nucleotide polymorphisms (single-nucleotide polymorphisms, SNPs), which could be found in non-coding regions of the genome. Recall that nucleotides are individual "letters" of the genetic code. DNA includes only four types of nucleotides, which differ in a certain functional group, which can be adenine (A), thymine (T), guanine (G) or cytosine (C). Nucleotide substitutions in non-coding regions of the genome do not affect the structure of proteins, so they can accumulate relatively easily. But in the case of the genome of the causative agent of leprosy, even in such regions, the researchers were able to select only three variable loci for analysis (in Latin, this term simply means “place”).

Well, even scanty material often reveals something important if the deductive method is applied correctly. Let's say we have three single nucleotide loci. How many types of nucleotides are possible at each locus? That's right, four: A, T, G or C. This means that the total number of combinations possible here is 64 (4 to the third power).

The first valuable information obtained by the researchers was that in real populations M. leprae out of 64 potential combinations, there are only four: C-G-A, C-T-A, C-T-C and T-T-C. This drastically simplifies the system under study. It remains only to understand from which of the combinations all the others originated.

Four lines correspond to hypotheses about the primitiveness of any of the four genetic types of the causative agent of leprosy. In cages shows the number of substitutions that would be needed to make each real type (four columns) from the original type. On right the number of replacements required is summed over all types. The fewer substitutions, the more plausible is the hypothesis about the primitiveness of this variant" border="0">

This is where the deductive method comes in handy. First of all, we see that in three out of four variants C is in the first position (see table). In modern evolutionary studies (especially molecular studies), the so-called principle of parsimony has been adopted, according to which, other things being equal, one should always choose the version that requires the least number of assumptions about independent events. In this case, this means that C in the first position should be considered a primitive state (it is easy to see that any other version would require additional substitutions to be postulated). Thus, the fourth genetic type, T-T-Ts, is excluded from the candidates for the role of the most ancient one.

In the second position in three of the four options is T. Similarly, we must assume that this state is primitive. Then the first genetic type (C-G-A) is also excluded from the candidates for the role of the most ancient.

This means that the most ancient genetic type of the causative agent of leprosy had C in the first position, and T in the second. But C-T-A or C-T-C? The primitiveness of both options is equally probable. The resolving power of the purely genetic approach is exhausted here.

However, any evolution takes place not only in the abstract space of genotypes, but also in the usual geographical one. Important additional information can be obtained by overlaying genetic types on a world map. Fortunately, the Mono group obtained samples of bacteria from various countries of the Earth.

For convenience, genetic types M. leprae were color coded. The first type (Ts-G-A) is “yellow”, the second (Ts-T-A) is “red”, the third (Ts-T-Ts) is “purple” and the fourth (T-T-Ts) is “ green". Judging by genetic considerations, the "red" and "violet" types can equally likely claim the role of the most ancient. Now let's see what their geographical distribution tells us.

Genomics Meets Geography

First, we give a dry summary of the data obtained.

"Yellow" type: East Africa (southern part), Madagascar, India, Korea, Malaysia, Philippines.

"Red" type: East Africa (Ethiopia, Malawi), Nepal, northeast India.

"Purple" type: North Africa (Morocco), Western Europe, most of the Americas.

"Green" type: Western Africa (sub-Saharan Africa), Caribbean islands, Brazil.

Three types are found in New Caledonia at once (“yellow”, “red” and “purple”), but this is a clear consequence of the settlement of the island by different ethnic groups during the colonial period, and therefore we can not be distracted by this.

What is the oldest type? If you choose between "red" and "purple" types, then "red" is, of course, preferable. European leprosy is definitely less ancient (for example, in Italy it was completely unknown even during the time of Emperor Augustus, that is, at the turn of our era). And in Africa, the "purple" type is found only north of the Sahara, for example in Morocco, where the connection with Europe is relatively close. But the range of the "red" type covers the whole of East Africa. So this is the birthplace of leprosy? Quite possible.

True, there is still a hypothesis of the Asian origin of leprosy, which Monod and his co-authors also did not immediately completely discard. But from a genetic point of view, this version is less likely: it involves at least one additional nucleotide substitution. Most likely, the original was not the "yellow" (Asian) type, but the "red". This means that leprosy originated in the same place as the species Homo sapiens: deep in East Africa.

From Africa, leprosy came primarily to the Middle East, and then it had two ways - to Europe or to Asia. Migration towards Europe gave rise to the "purple" type, migration towards Asia - "yellow". The nutrient medium for the latter was primarily the ancient states of the Indian subcontinent and China. In Europe, such a number of people simply did not exist for a long time, and the conditions for the survival of lepers there were more severe.

Interestingly, an island of the "red" - East African - type was noted just on the Indian subcontinent (Nepal, northeast India). Perhaps this is a relic left from the original migration.

On the other hand, the "yellow" - Asian - line of leprosy is also found in Africa. But what is Africa? This is Madagascar and the southern part of East Africa, located approximately opposite it. The current indigenous people of Madagascar - the Malagasy - are known to be descendants of the Indonesians. And in the southern part of East Africa there are old ports focused on trade with Asia - Malindi, Mombasa, Zanzibar. There is no doubt that leprosy was brought here from Asia, across the Indian Ocean.

The fate of the "green" line of leprosy is very interesting. It is very genetically removed from the supposedly original "red" type, and its distribution is limited to West Africa south of the Sahara. How did she get there? Perhaps by way of ancient continental migrations across Africa from east to west. This continent is not particularly suitable for long journeys, so isolation is understandable. Or maybe the Phoenicians, who sailed on ships along the African coast of the Atlantic, at one time brought leprosy there from the Mediterranean (here we can recall Ivan Efremov’s novel “On the Edge of the Oikumene”, which describes just such journeys). Indirectly in favor of this version is the fact that the "green" type of the causative agent of leprosy is genetically closer not to "red", but to "purple" - for the Mediterranean, as well as for Europe, it is the latter that is characteristic.

In the Americas, leprosy is mostly "purple", which looks quite natural: America was colonized by Europeans. In the Antilles and in Brazil, there is a "green" type of leprosy, but this is already clearly explained by the Atlantic slave trade - slaves at one time were transported mainly from West Africa.

It is noteworthy that immigrants from Europe seem to have managed to infect nine-banded armadillos widespread in South, Central and North America with leprosy. Dasypus novemcinctus. The nine-banded armadillo is almost the only non-human species to be affected by this disease. In the south of the United States and in Mexico, even natural foci have formed. So, armadillos have a genetic type M. leprae- "purple", exactly as one would expect, based on the fact that Europeans brought leprosy to America.

There are still a lot of questions here. But one way or another, we have a coherent evolutionary scenario.

... And with archeology

The scheme of evolution of the causative agent of leprosy, proposed by the Monod group, is beautifully reminiscent of Sherlock Holmes' solution to the problem with dancing men. It goes without saying that the research didn't stop there. A few years later, the same group published a clarifying paper in which the four genetic types M. leprae already divided into 16 subtypes ( Nature Genetics, 2009, 41, 12, 1282–1289). There is nothing fundamentally changing the picture, but there are interesting details. For example, DNA M. leprae, discovered in a leprosy skeleton from Egypt about 1500 years old, turned out to be not of the "red" type (as one might think), but of the "violet" type. The same is true in Turkey. It turns out that the area of ​​\u200b\u200bthe "purple" type covers the entire Mediterranean in a ring. In the exchange of leprosy pathogens between the Middle East and Europe - during the Crusades, for example - only the "purple" line of the microbe participated.

As for the “yellow” line, it apparently initially penetrated from Africa to Asia not through a land bridge between them (as it would again be easy to think), but in some other way. If "purple" type M. leprae moved from Egypt through Sinai, Palestine and Syria, then "yellow" - straight from the Somali Peninsula along the northern coast of the Indian Ocean. According to the Great Arc, as the heroes of Efremov would put it.

Here, however, there is reason to think.

Almost simultaneously with the release of a new article by the Mono group, data appeared on finds in India of leprosy skeletons as old as 2000 BC ( PloS One, 2009, 4, 5, e5669, see photo). There is no molecular evidence, but the anatomical (more precisely, osteological) look impressive. It is quite natural that the authors of this discovery questioned the hypothesis of the Monod group, suggesting that the original type of the causative agent of leprosy was, after all, not “red” (African), but “yellow” (Asian). As we remember, the Mono group itself did not completely reject such a version. But what is most interesting: the place where these skeletons were found is not just India, but Western India. This is the area of ​​the ancient civilization of the Indus Valley, the same one where the famous disappeared cities of Mohenjo-Daro and Harappa were. The Sumerians and Akkadians called this country Meluhha (History of the Ancient East. Edited by B.S. Lyapustin M., 2009).

At this point, the authors of the Indian discovery speak of the existence in the 2nd–3rd millennia BC of the so-called single sphere of interaction, which included Mesopotamia, Turan, Meluhha, and the kingdom of Magan on the Arabian Peninsula. Wherever leprosy originated, it was certain that it spread in that area. Urban civilizations were her breeding ground.

But which direction did she come from? Alas, there are purely genetic data that make us still reject the hypothesis of the origin of leprosy from India.

"Till the end of time"

One recent work has an estimate: about 10 million years ago ( PLoS Neglected Tropical Diseases, 2014, 8, 2, e2544). That's a lot! The oldest supposedly upright human relative, the Sahelanthropus, lived only 6–7 million years ago. And 10 million years ago, our upright posture was barely beginning to form. And in any case, all the initial stages of human evolution took place in Africa. If the causative agent of leprosy is so ancient, then it could only have appeared there.

It is known that many infectious diseases were somehow perceived by man from animals with which he had to contact ( Nature, 2007, 447, 7142, 279–283). About tuberculosis, which is also caused by a microorganism of the genus Mycobacterium, there is a hypothesis that humans got it from ruminant mammals. There is, however, a counter opinion that this is a very ancient purely human infection that infected ruminants a second time ( PLoS Pathogens, 2005, 1, 1, e5). As for leprosy, there are no such disputes, because there are no serious grounds for them. This is a human disease. True, armadillos still suffer from leprosy and very rarely (literally in isolated cases) chimpanzees, as well as some other African monkeys. But it looks like they all got their leprosy again from humans. The leper chimpanzee, imported from West Africa, has the genetic type M. leprae turned out to be "green", that is, exactly the one that is common among the local residents ( Future Microbiology, 2011, 6, 10, 1151–1157).

So, leprosy is a specific human disease. Given its antiquity, it is better to say not “humans”, but “hominid” (in the narrow sense of the word, upright primates). What features of their - our - way of life determined its existence?

The great anthropologist Owen Lovejoy attributes the emergence of bipedalism to a new breeding strategy that allowed hominids to dramatically increase their populations. With this strategy, females spend most of their lives in a small safe "nesting area" caring for children (they need to walk upright to free their hands for this work). Males, not shackled by cubs and females, can greatly expand their territory, making distant and risky foraging trips. The new structure of society has created new opportunities, but also new risks. In a herd of monkeys, the probability of survival of individuals affected by a severe slow infection is most likely low. But in the hominid space, clearly divided into a "nesting zone" (where females live), a foraging and hunting zone (where males make trips) and an absolutely wild outside world - here lepers could find for themselves at least gloomy and uncomfortable, but still niche.

“At Bruegel, the ascent to Golgotha, where the whole people follow Christ, is watched from afar by lepers: this is their place forever and ever,” wrote Michel Foucault. He did not yet know that it was "forever and ever", perhaps measured in millions of years. Leprosy is an ancient shadow of human society. It's even scary to imagine how old it is. One of those products of evolution that you most want to get rid of. Fortunately, modern means of treatment finally allow you to do this.

Leprosy (lat. lepra, Hansen's disease, hanseniasis, leprosy, Saint Lazarus' disease, ilephantiasis graecorum, lepra arabum, leontiasis, satyriasis, lazy death, black sickness, mournful disease) is a chronic infection with the acid-fast bacillus Mycobacterium leprae, which has a unique tropism for peripheral nerves, skin, and mucous membranes. Symptoms of leprosy (leprosy) are highly variable and include painless skin lesions and peripheral neuropathy. Diagnosis of leprosy (leprosy) is clinical and confirmed by biopsy. Leprosy (leprosy) is treated with dapsone in combination with other antibacterial agents.

ICD-10 code

A30 Leprosy [Gansen's disease]

B92 Sequelae of leprosy

Epidemiology

Although most cases are found in Asia, leprosy is also widespread in Africa. Endemic foci also exist in Mexico, South and Central America, and the Pacific Islands. Of the 5,000 cases in the United States, almost all were among immigrants from developing countries who settled in California, Hawaii and Texas. There are several forms of the disease. The most severe, lepromatous form, is more common in men. Leprosy can occur at any age, although the highest incidence is at 13-19 years of age and in 20-year-olds.

Until recently, humans were thought to be the only natural reservoir of leprosy, but 15% of armadillos have been found to be infected, and great primates may also be a reservoir for infection. However, with the exception of the transmissible route of infection (through bedbugs, mosquitoes), infection from animals is not a determining factor for human disease. M. leprae is also found in soil.

It is believed that the causative agent of leprosy is transmitted by sneezing and by secreting patients. An untreated patient with leprosy is a carrier of a large number of pathogens that are on the nasal mucosa and in secrets, even before the appearance of a clinic; about 50% of patients had close contact with an infected person, often with family members. Short contact results in a low risk of transmission. Non-severe tuberculoid forms are usually not contagious. Most (95%) immunocompetent persons do not become ill even after contact; those who get sick are likely to have a genetic predisposition.

Mycobacterium leprae grows slowly (doubling period 2 weeks). Usually the incubation period is 6 months - 10 years. With the development of infection, hematogenous dissemination occurs.

Symptoms of leprosy

Approximately 3/4 of patients with infection develop a single skin lesion that resolves spontaneously; the rest develop clinical leprosy. The symptoms of leprosy and the severity of the disease vary depending on the severity of cellular immunity to M. leprae.

Tuberculoid leprosy (oligobacillary Hansen's disease) is the mildest form of leprosy. Patients have a strong cell-mediated immunity that limits the disease to a few areas on the skin or individual nerves. Lesions contain little or no bacteria. The skin lesions contain one or more hypopigmented macules, with sharp, raised edges, and reduced sensation. The rash, as with all forms of leprosy, does not itch. Lesions are dry, as disorders of the autonomic nerves damage the innervation of the sweat glands. Peripheral nerves may be damaged asymmetrically and are palpated enlarged in adjacent skin lesions.

Lepromatous leprosy (polybacillary Hanean disease) is the most severe form of the disease. Affected patients have an insufficient immune response to M. leprae, as well as a systemic infection with the spread of bacterial infiltrates of the skin, nerves and other organs (nose, testicles and others). They may have spots, papules, nodes and plaques on their skin, often symmetrical (leprosy stuffed with mycobacteria). Gynecomastia, loss of fingers, and often severe peripheral neuropathy may develop. Patients lose eyelashes and eyebrows. The disease in Western Mexico and throughout Latin America causes a diffuse cutaneous infiltration with loss of body hair and other skin lesions, but no evidence of foci. This is called diffuse lepromatosis or leprosy bonita. Patients may develop subacute erythema nodosum, and patients with diffuse lepromatosis may develop the Lazio phenomenon, with ulcers, especially on the legs, which often serve as a source of secondary infection, leading to bacteremia and death.

Borderline leprosy (multibacillary) is intermediate and is the most common. The skin lesions resemble tuberculoid leprosy but are more numerous and irregular; affect the whole limb, peripheral nerves with the appearance of weakness, loss of sensitivity. This type has an unstable course and can turn into lepromatous leprosy or have a reverse development with a transition to the tuberculoid form.

Lepromatous reactions

Patients develop immunologically mediated reactions. There are two types of reactions.

The type 1 reaction develops as a result of a spontaneous increase in cellular immunity. They occur in about one third of patients with borderline leprosy, usually after the start of treatment. Clinically, there is an increase in inflammation within existing lesions with the development of skin edema, erythema, neuritis with pain, loss of function. New lesions may develop. These reactions play a significant role, especially in the absence of early treatment. As the immune response increases, this is referred to as a reversible response despite possible clinical deterioration.

The second type of reaction is a systemic inflammatory reaction resulting from the deposition of immune complex deposits. It is also called subacute erythema nodosum leprosy. Previously, it occurred in about half of patients with borderline and lepromatous forms of leprosy during the first year of treatment. Now it has become less frequent, as clofazimine is added to the treatment. It may also develop before treatment. It is a polymorphonuclear vasculitis or panniculitis with possible involvement of circulating immune complexes and increased T-helper function. Increased levels of tumor necrosis factor. Leprosy subacute erythema nodosum is erythematous painful papules or nodules with pustules and ulcers. When it develops fever, neuritis, lymphadenitis, orchitis, arthritis (large joints, especially knees), glomerulonephritis. As a result of hemolysis and bone marrow suppression, anemia, hepatitis with a moderate increase in functional tests may develop.

Complications and consequences

Leprosy (leprosy) has complications that develop as a result of peripheral neuritis, as a result of infection or leprosy reaction; there is a decrease in sensitivity and weakness. Nerve trunks and microscopic nerves of the skin, especially the ulnar nerve, may be affected, leading to the formation of claw-like digits 4 and 5. Branches of the facial nerve (buccal, zygomatic) and posterior auricular nerve may also be affected. Individual nerve fibers responsible for pain, temperature, and fine tactile sensation may be affected, while the larger nerve fibers responsible for vibration and position sensitivity are usually less affected. Surgical tendon repositioning can correct lagophthalmos and functional disorders of the upper extremities, but should be performed 6 months after the start of therapy.

Plantar ulcers with associated secondary infection are a major cause of disability and should be treated with removal of necrotic tissue and appropriate antibiotics. Patients should avoid weight bearing and wear an immobilizing bandage (Unna's boot) to keep their ability to move. To prevent recurrence, calluses should be treated, patients should wear special shoes made according to an individual model, or deep shoes that prevent friction of the foot.

The eyes can be very affected. In lepromatous leprosy or erythema nodosum leprosy, iritis can lead to glaucoma. Corneal numbness and damage to the zygomatic branch of the facial nerve (causing lagophthalmos) can lead to corneal trauma, scarring, and loss of vision. In such patients, it is necessary to use artificial lubricants (drops).

Nasal mucosa and cartilage may be affected, leading to chronic rhinorrhea and sometimes epistaxis. Less often, perforation of the nasal cartilage, nasal deformity, which usually occurs in untreated patients, may develop.

Men with leprosy may develop hypogonadism, as a result of a decrease in serum testosterone levels and an increase in follicle-stimulating and luteinizing hormones, with the development of erectile dysfunction, infertility and gynecomastia. Testosterone replacement therapy may relieve symptoms.

Patients with severe recurrent subacute erythema leprosy may develop amyloidosis with progressive renal failure.

Diagnosis of leprosy

The diagnosis of leprosy (leprosy) is based on the characteristic clinical presentation of skin lesions and peripheral neuropathy and is confirmed by microscopy of biopsy specimens; Microorganisms do not grow on artificial media. A biopsy is taken from the raised edges of tuberculoid lesions. In patients with the lepromatous form, a biopsy should be taken from nodules and plaques, although pathological changes can even be in normal areas of the skin.

The test for the detection of IgM antibodies to M. leprae is highly specific, but low sensitive. These antibodies are present in almost all patients with the lepromatous form, but only in 2/3 of patients with the tuberculoid form. Since the detection of such antibodies may indicate asymptomatic infection in endemic foci, the diagnostic value of the test is limited. They can be useful for monitoring disease activity, as antibody levels fall with effective chemotherapy and rise with relapse.

Treatment of leprosy

Leprosy has a favorable prognosis provided that the disease is treated in a timely manner, but cosmetic deformity leads to ostracism of patients and their families.

Medicines for leprosy

The main drug for the treatment of leprosy is dapsone 50–100 mg orally once a day (for children, 1–2 mg/kg). Side effects include hemolysis and anemia (moderate), allergic dermatitis, which can be quite severe; rarely, a syndrome that includes exopholative dermatitis, high fever, and changes in the blood test (leukocytes), as in mononucleosis (dapsone syndrome). Although cases of dapsone-resistant leprosy have been described, resistance is low and patients respond to conventional drug doses.

Rifampin is the first bactericidal drug for the treatment of M. leprae. But it is very expensive in many developing countries when given at the recommended doses of 600 mg orally once a day. Side effects are associated with treatment interruption and include hepatotoxicity, flu-like symptoms and, rarely, thrombocytopenia and renal failure.

Clofazimine has similar activity to dapsone against M. leprae at doses ranging from 50 mg orally once a day to 100 mg 3 times a week; 300 mg once a month is useful 1 (X) for the prevention of type 2 and possibly type 1 leprosy reactions. Side effects include gastrointestinal disturbances and reddish-dark skin dichromia.

Leprosy is also treated with ethionamide in doses of 250-500 mg orally once a day. However, it can frequently cause gastrointestinal disturbances and liver dysfunction, especially when used in conjunction with rifampin, and is not recommended unless regular monitoring of liver function is possible.

Recently, three antibiotics, minocycline (100 mg orally once daily), clarithromycin (500 mg orally twice daily), and ofloxacin (400 mg orally once daily), have been shown to rapidly kill M. leprae and reduce skin infiltration. Their combined bactericidal activity against M. leprae is higher than that of dapsone, clofazimine, and ethionamide, but not rifampin. Only minocycline has proven safety in long-term therapy, which is necessary for leprosy.

Although antimicrobial treatment of leprosy is effective, optimal regimens are unknown. In the United States, drug-susceptibility testing in mice is often recommended for patients with lepromatous and borderline forms of leprosy.

WHO recommends combination regimens for all forms of leprosy. Treatment of lepromatous leprosy requires more active regimens and duration than for tuberculoid leprosy. In adults, WHO recommends dapsone 100 mg once daily, clofazimine 50 mg once daily + 300 mg once monthly, and rifampin 600 mg once monthly for at least 2 years or until skin biopsy results are negative (approximately after 5 years). For tuberculoid leprosy without isolation of acid-fast bacilli, WHO recommends dapsone 100 mg once a day and rifampin 600 mg once a month for 6 months. Many authors from India recommend treatment for more than 1 year.

In the US, lepromatous leprosy is treated with rifampin 600 mg once a day for 2-3 years + dapsone 100 mg once a day for life. Tuberculoid leprosy is treated with dapsone 100 mg once daily for 5 years.

Lepromatous reactions

Patients with the first type of reaction (excluding minor inflammations) are given prednisone 40-60 mg orally once a day, starting at 10-15 mg once a day and increasing over several months. Small skin inflammations are not treated.

In the first or second episode of exacerbation of subacute erythema nodosum leprosy, in mild cases, aspirin can be prescribed, in more severe cases, prednisone 40-60 mg orally 1 time per day for 1 week plus antimicrobials. For relapses, thalidomide 100–300 mg orally once daily is given, but given its teratogenicity, it should not be given to women who may become pregnant. Side effects include constipation, mild leukopenia, and drowsiness.