What a plague. Plague is an acute infectious, especially dangerous disease. The causative agent of the bubonic plague is the bacterium Yersinia Pestis

Plague is a potentially serious infectious disease caused by the plague bacillus, pathogenic for humans and animals. Before the invention of antibiotics, disease was very high level mortality in Medieval Europe irrevocably changed the social and economic structure of society.

Great pandemics

The plague has left an indelible dark mark on the history of mankind, and it is not without reason that many peoples associate it with death. Even summary the misfortunes suffered can fill several volumes, and the history goes back thousands of years.

Ancient sources indicate that the disease was known in North Africa and the Middle East. It is assumed that this is what is described in the biblical book of Kings as a pestilence. But indisputable proof of its early existence is the DNA analysis of Bronze Age people, confirming the presence of the plague bacillus in Asia and Europe between 3 thousand and 800 BC. Unfortunately, the nature of these outbreaks cannot be verified.

During the time of Justinian

The first reliably confirmed pandemic occurred during the reign of the Byzantine Emperor Justinian in the 6th century AD.

According to historian Procopius and other sources, the outbreak began in Egypt and moved along maritime trade routes, striking Constantinople in 542. There, the disease claimed tens of thousands of lives in a short period of time, and the death rate grew so quickly that the authorities had problems getting rid of the corpses.

Judging by the descriptions of the symptoms and modes of transmission of the disease, it is likely that all forms of plague were raging in Constantinople at the same time. Over the next 50 years, the pandemic spread west to Mediterranean port cities and east to Persia. Christian authors, for example, John of Ephesus, considered the cause of the epidemic to be the wrath of God, and modern researchers are confident that it was caused by rats (constant passengers on sea ships) and the unsanitary living conditions of that era.

Black Death of Europe

The next pandemic hit Europe in the 14th century and was even more terrible than the previous one. The death toll reached, according to various sources, from 2/3 to ¾ of the population in the affected countries. There is evidence that During the rampant Black Death, about 25 million people died, although determining the exact amount is currently impossible. The plague, like last time, was brought by merchants on ships. Researchers suggest that the disease came to the southern ports of what is now France and Italy from the Genoese colonies of Crimea, spreading from Central Asia.

The consequences of this catastrophe not only left an imprint on the religious and mystical characteristics of the Europeans’ worldview, but also led to a change in the socio-economic formation.

The peasants who made up the main workforce became critically small. To maintain the same standard of living, it was necessary to increase labor productivity and change the technological structure. This need gave impetus to the development of capitalist relations in feudal society.

Great Plague of London

Over the next three centuries, small outbreaks of the disease were observed across the continent from the British Isles to Russia. Another epidemic broke out in London in 1664-1666. The number of deaths is expected to be between 75 and 100 thousand people. The plague spread rapidly:

• in 1666-1670 - in Cologne and throughout the Rhine Valley;
• in 1667-1669 - in the Netherlands;
• in 1675−1684 - in Poland, Hungary, Austria, Germany, Turkey and North Africa;

Briefly about the losses: in Malta - 11 thousand people died, in Vienna - 76 thousand, in Prague - 83 thousand. By the end of the 17th century, the epidemic began to gradually subside. The last outbreak was in the port city of Marseille in 1720, where it killed 40,000 people. After this, the disease was not recorded in Europe (with the exception of the Caucasus).

The decline of the pandemic can be explained by progress in sanitation and the use of quarantine measures, the fight against rats as carriers of the plague, and the abandonment of old trade routes. During the outbreaks in Europe, the causes of the disease were not well understood from a medical point of view. In 1768, the first edition of the Encyclopedia Britannica published the scientific opinion widespread among contemporaries about the emergence of plague fever from “poisonous miasma” or vapors brought from eastern countries with the air.

The best treatment was considered to be expulsion of the "poison", which was achieved either by natural rupture of the tumors or, if necessary, by incising and draining them. Other recommended remedies were:

• bloodletting;
• vomit;
• sweating;
• purgation.

During the 18th and early 19th centuries. the plague was recorded in the countries of the Middle East and North Africa, and in 1815−1836. appears in India. But these were only the first sparks of a new pandemic.

Latest in modern times

Having crossed the Himalayas and gained momentum in the Chinese province of Yunnan, in 1894 the plague reached Guangzhou and Hong Kong. These port cities became distribution centers for the new epidemic, which by 1922 was being imported by shipping throughout the world, more widely than in any previous era. As a result, about 10 million people from a variety of cities and countries died:

Almost all European ports were hit, but of the affected regions, India found itself in the worst situation. Only towards the end of the 19th century did the germ theory develop, and it was finally established which pathogen was responsible for so many deaths. All that remains is to determine how the bacillus infects humans. It has long been observed that in many epidemic areas unusual deaths of rats precede outbreaks of plague. The disease appeared in people some time later.

In 1897, the Japanese doctor Ogata Masanori, examining the outbreak of the disease on the island of Farmosa, proved that the plague bacillus was carried by rats. IN next year Frenchman Paul-Louis Simon demonstrated the results of experiments that showed that fleas of the species Xenopsylla cheopis are carriers of plague in the rat population. This is how the routes of human infection were finally described.

Since then, measures have been taken around the world to exterminate rats in ports and on ships, and insecticides have been used to poison rodents in areas of outbreaks. Since the 1930s, doctors have used sulfur-containing drugs to treat the population, and later antibiotics. The effectiveness of the measures taken is evidenced by the reduction in the number of deaths over the next decades.

Particularly dangerous infection

Plague is one of the deadliest diseases in human history. The human body is extremely susceptible to the disease, infection can occur both directly and indirectly. A defeated plague may emerge after decades of silence with even greater epidemic potential and significantly affect the population of entire regions. Due to its easy spread, it, along with botulism, smallpox, tularemia and viral hemorrhagic fevers(Ebola and Marburg) are included in group A of bioterrorism threats.

Methods of infection

The causative agent of plague is Y. Pestis, nonmotile rod-shaped anaerobic bacterium with bipolar staining, capable of producing antiphagocytic mucosa. Closest relatives:

The resistance of the plague pathogen to the external environment is low. Drying, sunlight, competition with putrefactive microbes kill it. Boiling a stick in water for a minute leads to its death. But it is able to survive on wet linen, clothes with sputum, pus and blood, and is stored for a long time in water and food.

IN wildlife and rural areas, most of the spread of Y. pestis is due to transmission between rodents and fleas. In cities, the main carriers are synanthropic rodents, primarily gray and brown rats.

The plague bacterium easily migrates from the urban environment to nature and back. It is usually transmitted to humans through the bites of infected fleas. But there is also information about more than 200 species of mammals (including dogs and cats) that can be carriers of the stick. Half of them are rodents and lagomorphs.

That's why The main rules of conduct in areas at risk of a disease outbreak will be:

• avoiding contact with wild animals;
• Be careful when feeding rodents and rabbits.

Pathogenesis and forms of the disease

The plague bacillus is characterized by a surprisingly stable and strong ability to multiply in the tissues of the host and lead to his death. After entering the human body, Y. Pestis migrates through the lymphatic system to the lymph nodes. There, the bacillus begins to produce proteins that disrupt the inflammatory reactions, blocking the fight of macrophages against infection.

Thus, the host's immune response is weakened, bacteria quickly colonize the lymph nodes, causing painful swelling, and eventually destroying the affected tissue. Sometimes they enter the bloodstream, leading to blood poisoning. During pathological and anatomical studies, their accumulations are found in the following organs:

• in the lymph nodes;
• spleen;
• in the bone marrow;
• liver.

The disease in humans has three clinical forms: bubonic, pulmonary and septic. Pandemics are most often caused by the first two. Bubonic without treatment turns into septic or pulmonary. Clinical manifestations for these three types look like this:

Treatment and prognosis

Whenever a diagnosis of plague is suspected on clinical and epidemiological grounds, appropriate specimens for diagnosis should be obtained immediately. Antibacterial therapy prescribed without waiting for a response from the laboratory. Suspicious patients with signs of pneumonia are isolated and treated with airborne precautions. The most applicable schemes:

Other classes of antibiotics (penicillins, cephalosporins, macrolides) have had varying success in treating this disease. Their use is ineffective and questionable. During therapy, it is necessary to provide for the possibility of complications such as sepsis. In the absence of medical care, the prognosis is not encouraging:

• pulmonary form - mortality 100%;
• bubonic - from 50 to 60%;
• septic - 100%.

Medicines for children and pregnant women

With proper and early treatment, complications of plague during pregnancy can be prevented. In this case the choice of antibiotics is based on analysis side effects the most effective drugs:

Experience has shown that a properly prescribed aminoglycoside is the most effective and safe for both the mother and the fetus. It is also recommended for use in the treatment of children. Due to the relative safety, the possibility of intravenous and intramuscular injection Gentamicin is the antibiotic of choice for treating children and pregnant women.

Preventive therapy

Persons who are in personal contact with persons with pneumonia or persons who are likely to have been exposed to fleas infected with Y. pestis, have had direct contact with body fluids or tissues of an infected mammal, or have been exposed to infection during laboratory research infectious materials must undergo antibacterial prophylactic therapy if contact occurred in the previous 6 days. The preferred antimicrobial agents for this purpose are tetracycline, chloramphenicol or one of the effective sulfonamides.

Administration of an antibiotic before infection may be indicated in cases where people must remain in plague-prone areas for short periods. This also applies to being in an environment where infection is difficult or impossible to prevent.

Precautionary measures for hospitals include a quarantine regime for all cases of plague. These include:

In addition, a patient with suspected pneumonic plague infection should be kept in a separate room and treated with precautions regarding the possibility of airborne infection of personnel. In addition to those listed, they include restricting the patient’s movement outside the room, as well as mandatory wearing of a mask in the presence of other persons.

Possibility of vaccination

Live attenuated and formalin-killed Y. pestis vaccines are available for use in different ways around the world. They are distinguished by their immunogenic and moderately high reactivity. It is important to know that they do not protect against primary pneumonia. In general, it is not possible to vaccinate communities against epizootic impacts.

Additionally, this measure is little used during human plague outbreaks because it takes a month or more for a protective immune response to develop. The vaccine is indicated for people in direct contact with the bacterium. These may be employees of research laboratories or people studying infected animal colonies.

Distemper of carnivores

This disease (Pestis carnivorum) is known among domestic dogs as distemper and is not related to Y. pestis. It is manifested by damage to the central nervous system, inflammation of the mucous membranes of the eyes and respiratory tract. Unlike human plague, it is viral in nature.

Currently, canine plague is recorded among domestic, wild and industrially bred animals in all countries of the world. Economic damage is expressed in losses from culling and slaughter, a decrease in the volume and quality of fur, and the costs of preventive measures, violation of the technological process of growing.

The disease is caused by an RNA virus 115−160 nm in size from the Paramyxoviridae family. Dogs, foxes, arctic foxes, Ussuri raccoons, otters, jackals, hyenas and wolves are susceptible to it. For different types In animals, the pathogenicity of the virus varies - from a latent asymptomatic course of the disease to an acute one with 100% mortality. Ferrets are the most sensitive to it. The canine distemper virus is very virulent, but does not pose a danger to humans.

Currently, the plague is a disease whose symptoms are well studied. Its foci remain in the wild and are preserved in permanent habitats of rodents. Modern statistics are as follows: throughout the world in one year, approximately 3 thousand people come into contact with this disease and about 200 of them die. Most cases occur in Central Asia and Africa.

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Treatment of plague

Causes of plague

Treatment of plague with traditional methods

Plague - aggressive and swift developing disease, application folk remedies in the treatment of which may be the same delay, which will subsequently lead to death. Plant extracts are not able to have a sufficient effect on the plague bacillus, especially in a short time, therefore, in case of any disturbing symptoms and the slightest suspicion of plague, it is recommended to urgently seek treatment medical care, and not try traditional medicine recipes.

Treatment of plague during pregnancy

Plague is a disease characterized by a high toxic effect, which for a pregnant woman usually means miscarriage. Treatment of plague in a pregnant woman, first of all, the goal is to preserve the life of the mother. After termination of pregnancy, treatment is carried out according to the standard regimen.

Planning a pregnancy and its course should be that period in a woman’s life when she in every possible way protects herself from negative influences. Plague for today

does not pose a danger to residents of our region, with the exception of the risk of its importation from enzootic foci and from abroad. This is prevented by workers of various anti-plague institutions. For immediate protection during a disease outbreak, WHO does not recommend vaccination. Vaccination is used only as preventative measure for high-risk groups (for example, laboratory workers). If plague occurs among the population, anti-epidemic measures are taken aimed at localizing and eliminating the epidemic focus. These include:

• identifying patients and hospitalizing them in special ward-boxes with special ventilation and a strict anti-epidemic regime;
• establishment of territorial state quarantine for cases of pneumonic plague and regular quarantine for other forms without pulmonary lesions;
• identification and isolation of all persons who were in contact with patients (they are isolated in pharmacist medical institutions for 6 days and given emergency prophylaxis with antibiotics - ciprofloxacin or doxycycline for 6 days);
• conducting door-to-door visits to identify patients with fever and their hospitalization in pharmacies;
• final disinfection in the plague outbreak with disinfectants and using steam and steam-formalin chambers, as well as disinsection and deratization in and around the populated area.

The personnel works in protective suits for working with category IV pathogens (anti-plague suits). In enzootic foci of plague, sanitary education work is of great importance.

A clinical blood test reveals significant leukocytosis with a shift to the left and an increase in ESR. In the urine there is protein, red blood cells, granular and hyaline casts. Oliguria develops.

The detection of an ovoid gram-negative rod, bipolarly stained, in a smear provides grounds for establishing a preliminary diagnosis of plague. WHO recommends rapid substrate-impregnated assays for use in the field to rapidly identify antigens in patients. Bacteriological examination is very important: sowing the material on Marten or Hottinger agar with sodium sulfite. To study the properties of the plague pathogen with a culture isolated from a patient, biological tests are carried out (intraperitoneal, subcutaneous, intradermal injection of material into guinea pigs or white mice). Serological tests play an important role: RPGA, RGPGA, RNAg, RNAb, ELISA with mono- or polyclonal antibodies. For express diagnostics, RIF is used, the result is obtained in 15 minutes. This test has 100% sensitivity and specificity.

All studies to detect plague are carried out in laboratories adapted, according to WHO definition, for working with pathogens of pathogenicity group IV (in Ukraine these are laboratories of especially dangerous infections), the work in which is regulated special instructions. The material is taken and sent to the laboratory in a suit according to the rules established for quarantine infections.

Treatment of other diseases starting with the letter - h

The information is for educational purposes only. Do not self-medicate; For all questions regarding the definition of the disease and methods of its treatment, consult your doctor. EUROLAB is not responsible for the consequences caused by the use of information posted on the portal.

It has natural foci (endemicity), with characteristic lesions of the lymph nodes, skin, lungs and severe general intoxication.

Relevance

Foci of plague are present on all continents except Australia and Antarctica. During the period from 1986 to 2004 World Organization Health care recorded about 24 thousand cases of plague, while the mortality rate was 7% of all cases (this is in the presence of modern antibiotics). The relevance of the infection is also high due to the use of the disease as a biological weapon (along with anthrax).

Historical reference

The first information about the plague dates back to Ancient writings as early as 1200 BC. The symptoms of this infection are also described in the Bible - Old Testament. Throughout the history of mankind, there have been several pandemics (unlike an epidemic, a pandemic is characterized by the involvement of all continents in the infection):

• "Justinian Plague" - 500 BC, the beginning of the pandemic occurred in Ancient Egypt, about 100 million people died.
• “Black Death” - in the 14th century, brought from China, about 25 million people died.
• the third plague pandemic - at the end of the 19th century, the countries of Asia were most affected, but outbreaks of plague were also recorded in Europe.
• plague epidemic Far East– currently the last recorded epidemic, about 100 thousand people died.

The bacterium that causes the plague was discovered in 1894 by the French scientist Alexandre Yersin (his name is the specific name of the pathogen - Yersinia).

Etiology of the disease

The causative agent of plague is a rod-shaped bacterium – Yersinia pestis. This is a non-motile bacterium of small size. Yersinia forms a capsule, which makes the microorganism pathogenic and allows it to attach to human cells. At the same time, cells of the immune system (macrophages) cannot actively destroy the pathogen due to the capsule. Another factor is the release of exotoxin and enzymes by the bacterium that facilitate penetration (invasion) into the human body.

In the external environment, the plague causative agent is quite persistent - it can survive in soil for up to several months, however, ordinary disinfectants kill the bacterium within a few minutes.

Epidemiology of the disease

Plague is a zoonotic infection, the main source in natural foci are rodents (gophers, mice, hamsters, rats, hares); in total, about 250 animal species can accumulate and transmit the pathogen. A considerable number of epidemics are associated with the migration of these animals and the spread of infection. In rodents, plague occurs in chronic form, so the animal long time releases the pathogen into the external environment. Microorganisms are transmitted by fleas, into which the bacteria enter through the blood. In urban areas, the main reservoir of plague are black and gray rats.

• transmissible route - infection occurs through the bite of fleas infected from animals;
• contact route - when processing the carcasses of animals suffering from plague (most often implemented by hunters), this route of transmission of plague is also possible if personal safety rules are not followed when caring for a person sick with plague;
• nutritional route - when eating meat of infected animals (in Turkmenistan, cases of the disease are known in people who ate gopher meat);
• airborne droplets and airborne dust - possible with the pneumonic form of plague in humans, when the pathogen is released in large quantities with exhaled air (the most dangerous route of transmission, since infection is possible large quantity of people).

The mechanism of plague development

The characteristic development of the plague disease is associated with such a feature of the pathogen as the formation of capsules. When the bacterium enters the skin through a flea bite or through contact, it spreads through the lymphatic vessels and enters the regional lymph nodes. Here the immune defense mechanism turns on, and macrophages try to capture the pathogen. However, thanks to the capsule, incomplete phagocytosis occurs - the bacteria in the macrophages do not die, but begin to multiply. This leads to the development of inflammation and necrosis (death) of the lymph nodes with the formation of buboes (bubonic plague). Next from lymphatic vessels The plague bacterium enters the blood and spreads throughout the body (septic form of plague) with the development of intoxication and multiple organ failure. In this case, the development of infectious-toxic shock and death of the patient is possible. In the pneumonic form of plague, the process is localized in the lungs, the immune system also cannot “cope” with the bacterium, severe pneumonia occurs.

Plague symptoms

The incubation period (the time from the moment of infection to the appearance of the first signs of the disease) ranges from several hours to 6 days. There are several clinical forms of plague, which depend on the route of transmission:

Specific diagnosis of plague

Consists of using several laboratory methods diagnostics:

• microscopic method - is an indicative method, used at the onset of the disease when plague is suspected. To do this, a Gram-stained microscopy of the patient’s material is performed; the result can be obtained in 1-2 hours.
• The bacteriological method is the main method for diagnosing plague; the material is inoculated on nutrient media, and after 48 hours the culture is identified. The sensitivity of bacteria to antibiotics is also studied.
• serological method - is based on identifying a growing titer of antibodies in the patient’s blood to the plague causative agent; it is important no earlier than a week from the onset of the disease.

Treatment of plague

The effectiveness of treatment depends on how early it is started. Therefore, if plague is suspected, specific etiotropic (aimed at destroying the pathogen in the patient’s body) treatment is started without waiting for laboratory confirmation of the diagnosis. All patients are treated only in a specialized infectious diseases hospital. Patients with the bubonic form of plague are placed in groups of several people in a ward, while those with the pneumonic form are placed only in boxes with one person each. The hospital is under a strict anti-epidemic regime, the staff works in anti-plague suits, all discharge from patients is thoroughly disinfected. Contact people are also isolated and given preventive (preventing the development of the disease) antibiotic therapy.

In general, treatment is divided into the following types:

• etiotropic therapy - aimed at destroying the pathogen in the human body, is the main one in treatment; the earlier this therapy is started, the better the prognosis for the patient. Antibiotics are used for this - streptomycin, tetracycline, doxycycline. If these antibiotics are ineffective, ciprofloxacin is prescribed intravenously.
• pathogenetic therapy - the goal is to reduce general intoxication, removing toxins from human blood. To do this, intravenous infusion of colloidal and saline solutions is performed.
• symptomatic therapy– used to alleviate the patient’s condition; for severe pain in the buboes, painkillers and anti-inflammatory drugs are used.

The prognosis for the treatment of cutaneous and bubonic plague is favorable (if adequate treatment is started early). In the case of the development of septic or pneumonic plague, the prognosis is unfavorable, mortality reaches 90-95%.

Discharge from the hospital is carried out no earlier than 4-6 weeks after the disappearance of symptoms of the disease, after triple bacteriological examination with negative results.

Prevention of plague

Prevention is important event aimed at preventing the spread of the plague and the development of the epidemic. There are nonspecific prevention and anti-epidemic measures in case of suspected plague.

Nonspecific prevention includes a number of activities:

• obtaining and analyzing information on the status of plague in different countries Oh;
• health examination Vehicle and their passengers arriving from other countries;
• identification, isolation and treatment of patients with suspected plague;
• disinfection of transport that arrived from countries affected by the plague.

In natural foci of plague, the number of rodents is monitored, they are examined to identify the causative agent of the plague, and sick animals are destroyed.

Anti-epidemic measures are carried out if at least one patient with suspected plague is identified:

• imposing a quarantine on a populated area, with a ban on entry and exit of the population (except medical workers) for 6 days;
• drug prevention of plague in contacts, use of antibiotics for at least 6 days, their isolation and observation;
• Thorough disinfection is carried out in the plague outbreak;
• contact people are given an anti-plague vaccine - the vaccine (EV strain) is applied cutaneously, and immunity develops within 1 month and lasts 3-6 months.

It is worth remembering that the plague, even with modern capabilities medicine is very dangerous infectious disease with high mortality. The circulation of the plague pathogen among animals does not make it possible to completely destroy this infection or transfer it to the controlled category. Therefore, at the slightest sign of plague, it is necessary to immediately seek medical help, because a person’s life depends on how early treatment is started.

Bubonic plague is a very ancient Asian disease that affected the population of different countries and continents. She took away millions human lives in Europe and it was called the “Black Death” or “Karaj Plague”. The death rate from the plague reached 95%, although some people who fell ill miraculously recovered on their own. Until the end of the 19th century, this serious disease could not be treated. Only after the invention of vaccines against plague and the beginning of the use of certain antibiotics (streptomycin, etc.) in practice, many patients began to recover, for whom treatment began on time.

Now this disease is occasionally observed in some regions of Iran, Brazil, Nepal, Mauritania, etc. In Russia, bubonic plague has not appeared since the seventies of the twentieth century, but the danger of an outbreak of such an epidemic exists and frightens many. Its last closest source was eliminated in Kyrgyzstan in 2013: a 15-year-old teenager died due to this disease. There was also a case of bubonic plague in 2009 in China.

That is why many citizens of Russia and CIS countries are interested in information about this serious disease. In our article we will tell you about the causative agent, sources, modes of transmission, symptoms, diagnostic methods, treatment and prevention of bubonic plague.

Plague

Known as the Black Death, this disease is one of the oldest known diseases and is found throughout the world. In the 14th century, spreading throughout Europe, it destroyed a third of the population.

The causative agent of the disease is the bacterium Yersinia Pestis, and is primarily a disease of rodents, especially rats. Human plague can occur in areas where the bacteria are present in wild rodents. As a rule, the most high risk infestations in rural areas, including in homes where ground squirrels, chipmunks, and tree rats find food and shelter, as well as other places where rodents may be encountered.

People most often become infected with plague when they are bitten by fleas infected with plague bacteria. People can also become infected through direct contact with infected tissue or fluids of an animal that has or has died from distemper. Finally, people can become infected through the air through close contact with cats or a person with pneumonic plague.

The disease comes in three forms: bubonic plague, septicemic plague and pneumonic plague.

Pathogen, sources and routes of transmission of bubonic plague

Bubonic plague develops in humans after infection with the bacterium Yersinia pestis. These microorganisms live on the body (field mice, hamsters, gophers, squirrels, hares). They become carriers of the plague bacillus: they bite a rodent, swallow the pathogen along with its blood, and it actively multiplies in the digestive tract of the insect. The flea then becomes a carrier of the disease and spreads it to other rats.

When such a flea bites another animal or person, Yersinia becomes infected through the skin. Further, this disease can be transmitted from person to person through airborne droplets or through contact with the secretions and sputum of a patient, household items or utensils of an infected person.

There are the following transmission routes for the causative agent of bubonic plague:

• transmissible (when bitten through blood);
• airborne;
• fecal-oral;
• contact-household.

Bubonic plague is especially dangerous infection. It is characterized by a high ability to spread rapidly and is highly contagious. In terms of its contagiousness, the bubonic form of plague is the most contagious infectious disease.

Symptoms

The incubation period for infection with the causative agent of bubonic plague ranges from several hours to 2-3 days. Sometimes it can extend to 6-9 days in people who took streptomycin, tetracycline or immunoglobulin for prophylaxis.

The causative agent of the disease, getting into the inguinal and axillary lymph nodes, is captured by blood leukocytes and spreads throughout the body. Bacteria actively multiply in the lymph nodes, and they cease to perform their protective function, turning into a reservoir for infection.

The first symptoms of the disease appear suddenly. The patient develops a fever and complains of general weakness, chills, headaches and vomiting. In some cases, there are complaints of hallucinations and insomnia.

• bubonic;
• pulmonary;
• septic.

Bubonic form

The most common form of plague observed after infection with Yersinia pestis is the bubonic form of plague. The patient develops a rash at the site of the insect bite. It quickly turns into a pustule with bloody-purulent contents. After opening the pustule, an ulcer forms in its place.

Approximately 7 days after communicating with the patient, a sharp increase in temperature appears, headache, chills and weakness, 1–2 or more enlarged, painful lymph nodes (called buboes) appear. This form is usually the result of an infected flea bite. Bacteria multiply in the lymph nodes that are closest to the bite site. If the patient is not treated with appropriate antibiotics, the infection may spread to other parts of the body.

Already on the second day, the patient’s axillary, inguinal or other lymph nodes significantly enlarge (they can reach the size of a lemon). The inflammatory process begins in it, it becomes painful and compacted - this is how the primary bubo is formed. In the following days, the infection spreads to other lymph nodes; they also become inflamed, enlarge and form secondary buboes. The skin over the affected lymph nodes becomes red, inflamed and shiny. The buboes become clearly defined and dense.

After 4 days of illness, the inflamed lymph nodes become more soft consistency, when you tap on them, they vibrate. By day 10, the buboes open and fistulas form in their place.

Yersinia pestis constantly produces potent toxins, and bubonic plague is accompanied by symptoms of severe intoxication. From the first day of the disease, the patient experiences rapidly increasing symptoms:

• severe weakness, and headache;
• muscle pain throughout the body;
• nervous excitement.

The patient's face becomes puffy and darkens, black circles appear under the eyes, and the conjunctiva becomes bright red. The tongue is covered with a thick white coating.

Intoxication causes disturbances in... The patient's arterial pressure, the pulse becomes rare and weak. As the disease progresses, heart failure can cause the patient's death.

Bubonic plague can be complicated. When the patient experiences excruciating headaches, convulsions and severe tension in the neck muscles.

Pulmonary form

Fever, headache, weakness, rapidly developing pneumonia with chest pain, cough with bloody or watery sputum are observed. Pneumonic plague can be contracted through the air, or occurs secondary to bubonic or septicemic plague, which spreads to the lungs. Pneumonia can cause respiratory failure and shock. Pneumonic plague is the most serious form of the disease and the only form of plague that can be transmitted from person to person (by airborne transmission).

If left untreated, the disease quickly spreads throughout the body through lymphatic system. But the plague is successfully treated with antibiotics. The patient develops plague, which is accompanied by cough, sputum mixed with blood, shortness of breath and cyanosis skin. Such forms of the disease, even with active treatment, can result in death in 50-60% of patients.

In the era without antibiotics, the death rate from plague was about 66%. Antibiotics significantly reduce mortality, and overall mortality has now dropped to 11%. Despite the presence effective antibiotics, plague is still a deadly disease, but bubonic plague has a lower mortality rate than the septic or pneumonic form.

In most cases, this disease is complicated by DIC syndrome, in which the patient's blood clots inside the vessels. In 10% of cases, bubonic plague leads to gangrene of the fingers, skin or feet.

Septic form

Symptoms include fever, chills, severe weakness, abdominal pain, shock, and possible intradermal bleeding and hemorrhage into other organs. The skin and other tissues turn black and die, especially on the fingers, toes, and nose. Septicemic plague can be primary or develop as a consequence of untreated bubonic plague. Infection occurs through the bites of infected fleas or through contact with an infected animal.

With septicemic plague, the patient does not develop buboes or pulmonary symptoms. From the very beginning of the disease, he exhibits general nervous disorders, which, without treatment, end in death in 100% of cases. With timely treatment with streptomycin, septicemic plague is highly curable.

Diagnostics

To diagnose bubonic plague, contents are collected from inflamed lymph node using his puncture. 1 ml of saline is injected into it, and after 5 minutes its contents are sucked into a syringe. Next, the bubo juice is inoculated onto a nutrient medium (blood agar) and bacteriologically examined.

The patient must undergo a culture of his stool. Next, a pure culture of the pathogen is isolated and carefully studied in the laboratory.

Treatment

All patients with bubonic plague are subject to mandatory hospitalization in specialized departments of infectious diseases hospitals. Linen, clothing, leftover food, dishes, care items and patient waste are subject to special treatment and disinfection. During treatment and care of patients, the department staff uses anti-plague suits.

The main treatment for bubonic plague is antibiotic therapy. These drugs are administered intramuscularly and inside the buboes. Tetracycline or streptomycin are used for this.

Except antibacterial drugs, the patient is prescribed symptomatic therapy, which is aimed at alleviating his condition and treating complications of bubonic plague.

The patient's recovery is confirmed by three negative bacteriological culture results. After this, the patient remains in the hospital under the supervision of doctors for another month, and only after that he is discharged. Recovered patients must be monitored by an infectious disease specialist for another 3 months.

Prevention

Measures to prevent bubonic plague are aimed at preventing the spread of infection and blocking the sources of its causative agent. To do this, regular monitoring of the number of rodents in nature and constant extermination of rats, mice and fleas (especially on ships and airplanes) is carried out.

Plague (pestis) - acute zoonotic natural focal infectious disease with a predominantly transmissible mechanism of transmission of the pathogen, which is characterized by intoxication, damage to the lymph nodes, skin and lungs. It is classified as a particularly dangerous, conventional disease.

Codes according to ICD -10

A20.0. Bubonic plague.
A20.1. Cellulocutaneous plague.
A20.2. Pneumonic plague.
A20.3. Plague meningitis.
A20.7. Septicemic plague.
A20.8. Other forms of plague (abortive, asymptomatic, minor).
A20.9. Unspecified plague.

Etiology (causes) of plague

The causative agent is a gram-negative small polymorphic non-motile bacillus Yersinia pestis of the Enterobacteriaceae family of the genus Yersinia. It has a mucous capsule and does not form spores. Facultative anaerobe. Dyed with bipolar aniline dyes (more intense at the edges). There are rat, marmot, gopher, field and sand lance varieties of the plague bacterium. Grows on simple nutrient media with the addition of hemolyzed blood or sodium sulfate, the optimal temperature for growth is 28 ° C. It occurs in the form of virulent (R-forms) and avirulent (S-forms) strains. Yersinia pestis has more than 20 antigens, including a thermolabile capsular antigen, which protects the pathogen from phagocytosis by polymorphonuclear leukocytes, a thermostable somatic antigen, which includes V- and W-antigens, which protect the microbe from lysis in the cytoplasm of mononuclear cells, ensuring intracellular reproduction, LPS etc. The pathogenicity factors of the pathogen are exo- and endotoxin, as well as aggression enzymes: coagulase, fibrinolysin and pesticins. The microbe is resistant to environment: persists in soil for up to 7 months; in corpses buried in the ground, up to a year; in bubo pus - up to 20–40 days; on household items, in water - up to 30–90 days; tolerates freezing well. When heated (at 60 °C it dies in 30 s, at 100 °C - instantly), drying, exposure to direct sunlight and disinfectants(alcohol, chloramine, etc.) the pathogen is quickly destroyed. It is classified as pathogenicity group 1.

Epidemiology of the plague

The leading role in preserving the pathogen in nature is played by rodents, the main ones being marmots (tarbagans), ground squirrels, voles, gerbils, as well as lagomorphs (hares, pikas). The main reservoir and source in anthropurgic foci are gray and black rats, less often - house mice, camels, dogs and cats. A person suffering from pneumonic plague is especially dangerous. Among animals, the main distributor (carrier) of plague is the flea, which can transmit the pathogen 3–5 days after infection and remains infective for up to a year. Transmission mechanisms are varied:

• transmissible - when bitten by an infected flea;
• contact - through damaged skin and mucous membranes when skinning sick animals; slaughter and cutting of camel, hare carcasses, as well as rats, tarbagans, which are used as food in some countries; in contact with the secretions of a sick person or objects contaminated by him;
• fecal-oral - when eating insufficiently heat-treated meat from infected animals;
• aspiration - from a person suffering from pulmonary forms of plague.

Diseases in humans are preceded by epizootics among rodents. The seasonality of the disease depends on the climate zone and in countries with a temperate climate is recorded from May to September. Human susceptibility is absolute in all age groups and for any mechanism of infection. A patient with the bubonic form of plague before the opening of the bubo does not pose a danger to others, but when it passes into the septic or pneumonic form, he becomes highly infectious, releasing the pathogen with sputum, bubo secretions, urine, and feces. Immunity is unstable, repeated cases of the disease have been described.

Natural foci of infection exist on all continents, with the exception of Australia: in Asia, Afghanistan, Mongolia, China, Africa, South America, where about 2 thousand cases of illness are registered annually. In Russia, there are about 12 natural focal zones: in the North Caucasus, Kabardino-Balkaria, Dagestan, Transbaikalia, Tuva, Altai, Kalmykia, Siberia and the Astrakhan region. Anti-plague specialists and epidemiologists are monitoring the epidemic situation in these regions. Over the past 30 years, cluster outbreaks have not been registered in the country, and the incidence rate has remained low - 12–15 episodes per year. Each case of human disease must be reported to the territorial center of Rospotrebnadzor in the form emergency notice followed by the announcement of quarantine. International rules specify quarantine lasting 6 days, observation of persons in contact with the plague is 9 days.

Currently, the plague is included in the list of diseases, the causative agent of which can be used as a means of bacteriological weapons (bioterrorism). Laboratories have obtained highly virulent strains that are resistant to common antibiotics. In Russia there is a network of scientific and practical institutions to combat infection: anti-plague institutes in Saratov, Rostov, Stavropol, Irkutsk and anti-plague stations in the regions.

Plague prevention measures

Nonspecific

• Epidemiological surveillance of natural plague foci.
• Reducing the number of rodents, carrying out deratization and disinfestation.
• Constant monitoring of the population at risk of infection.
• Preparation medical institutions and medical personnel to work with plague patients, conducting awareness-raising work among the population.
• Prevention of pathogen importation from other countries. The measures to be taken are set out in the International Health Regulations and the Sanitation Regulations.

Specific

Specific prevention consists of annual immunization with a live anti-plague vaccine of persons living in epizootic outbreaks or traveling there. People who come into contact with plague patients, their belongings, and animal corpses are given emergency chemoprophylaxis (Table 17-22).

Table 17-22. Schemes for the use of antibacterial drugs for emergency prevention plague

Pathogenesis of plague

The causative agent of plague enters the human body most often through the skin, less often through the mucous membranes of the respiratory tract and digestive tract. Changes in the skin at the site of pathogen penetration (primary focus - phlyctena) rarely develop. Lymphogenously from the site of introduction, the bacterium enters the regional lymph node, where it multiplies, which is accompanied by the development of serous-hemorrhagic inflammation, spreading to surrounding tissues, necrosis and suppuration with the formation of a plague bubo. When the lymphatic barrier breaks through, hematogenous dissemination of the pathogen occurs. Entry of the pathogen through the aerogenous route promotes the development inflammatory process in the lungs with melting of the walls of the alveoli and concomitant mediastinal lymphadenitis. Intoxication syndrome is characteristic of all forms of the disease, is caused by the complex action of pathogen toxins and is characterized by neurotoxicosis, ITS and thrombohemorrhagic syndrome.

Clinical picture (symptoms) of plague

The incubation period lasts from several hours to 9 days or more (on average 2–4 days), shortening in the primary pulmonary form and lengthening in vaccinated individuals.
or receiving prophylactic medications.

Classification

There are localized (cutaneous, bubonic, cutaneous bubonic) and generalized forms of plague: primary septicemic, primary pulmonary, secondary septic, secondary pulmonary and intestinal.

Main symptoms and dynamics of their development

Regardless of the form of the disease, plague usually begins suddenly, and the clinical picture from the first days of the disease is characterized by a pronounced intoxication syndrome: chills, high fever (≥39 ° C), severe weakness, headache, body aches, thirst, nausea, and sometimes vomiting. The skin is hot, dry, the face is red and puffy, the sclera is injected, the conjunctiva and mucous membranes of the oropharynx are hyperemic, often with pinpoint hemorrhages, the tongue is dry, thickened, covered with a thick white coating (“chalky”). Later, in severe cases, the face becomes haggard, with a cyanotic tint, dark circles under the eyes. Facial features become sharper, an expression of suffering and horror appears (“plague mask”). As the disease progresses, consciousness is impaired, hallucinations, delusions, and agitation may develop. Speech becomes slurred; coordination of movements is impaired. Appearance and the behavior of patients resembles a state of alcohol intoxication. Characteristic arterial hypotension, tachycardia, shortness of breath, cyanosis. In severe cases of the disease, bleeding and vomiting mixed with blood are possible. The liver and spleen are enlarged. Oliguria is noted. The temperature remains constantly high for 3–10 days. In the peripheral blood - neutrophilic leukocytosis with a shift to the left. In addition to those described common manifestations plague, lesions develop that are characteristic of individual clinical forms of the disease.

Cutaneous form is rare (3–5%). At the site of the entrance gate of infection, a spot appears, then a papule, a vesicle (phlyctena), filled with serous-hemorrhagic contents, surrounded by an infiltrated zone with hyperemia and edema. Phlyctena is characterized by severe pain. When it is opened, an ulcer forms with a dark scab at the bottom. A plague ulcer has a long course and heals slowly, forming a scar. If this form is complicated by septicemia, secondary pustules and ulcers occur. The development of a regional bubo (cutaneous bubonic form) is possible.

Bubonic form occurs most often (about 80%) and is distinguished by its relatively benign course. From the first days of the disease, sharp pain appears in the area of ​​the regional lymph nodes, which makes movement difficult and forces the patient to take a forced position. The primary bubo, as a rule, is single; multiple buboes are less often observed. In most cases, the inguinal and femoral lymph nodes are affected, and somewhat less frequently, the axillary and cervical lymph nodes. The size of the bubo varies from a walnut to a medium-sized apple. Vivid features are sharp pain, dense consistency, adhesion to the underlying tissues, smoothness of contours due to the development of periadenitis. The bubo begins to form on the second day of illness. As it develops, the skin over it turns red, shiny, and often has a cyanotic tint. At the beginning it is dense, then it softens, fluctuation appears, and the contours become unclear. On the 10th–12th day of illness, it opens - a fistula and ulceration form. With a benign course of the disease and modern antibiotic therapy, its resorption or sclerosis is observed. As a result of hematogenous introduction of the pathogen, secondary buboes can form, which appear later and are small in size, less painful and, as a rule, do not suppurate. A serious complication of this form can be the development of a secondary pulmonary or secondary septic form, which sharply worsens the patient’s condition, even leading to death.

Primary pulmonary form It occurs rarely, during periods of epidemics in 5–10% of cases and represents the most dangerous epidemiologically and severe clinical form of the disease. It begins sharply, violently. Against the background of a pronounced intoxication syndrome, a dry cough, severe shortness of breath, and cutting pain in the chest appear from the first days. The cough then becomes productive, with the production of sputum, the amount of which can vary from a few spits to huge quantities, it is rarely absent at all. The sputum, at first foamy, glassy, ​​transparent, then takes on a bloody appearance, later becomes purely bloody, and contains a huge amount of plague bacteria. It usually has a liquid consistency - one of the diagnostic signs. Physical data are scanty: a slight shortening of the percussion sound over the affected lobe; on auscultation, there are not a lot of fine wheezes, which clearly does not correspond to the general serious condition of the patient. The terminal period is characterized by an increase in shortness of breath, cyanosis, development of stupor, pulmonary edema and ITS. Blood pressure drops, the pulse quickens and becomes thread-like, heart sounds are muffled, hyperthermia is replaced by hypothermia. Without treatment, the disease ends in death within 2–6 days. With early use of antibiotics, the course of the disease is benign and differs little from pneumonia of other etiologies, as a result of which late recognition of the pneumonic form of plague and cases of the disease in the patient’s environment are possible.

Primary septic form It happens rarely - when a massive dose of the pathogen enters the body, usually by airborne droplets. It begins suddenly, with pronounced symptoms of intoxication and subsequent rapid development clinical symptoms: multiple hemorrhages on the skin and mucous membranes, bleeding from internal organs(“black plague”, “black death”), mental disorders. Signs of cardiovascular failure progress. The patient's death occurs within a few hours from ITS. There are no changes at the site of introduction of the pathogen and in the regional lymph nodes.

Secondary septic form complicates other clinical forms of infection, usually bubonic. Generalization of the process significantly worsens general state patient and increases his epidemiological danger to others. Symptoms are similar to those described above clinical picture, but differ in the presence of secondary buboes and a longer course. With this form of the disease, secondary plague meningitis often develops.

Secondary pulmonary form as a complication occurs in localized forms of plague in 5–10% of cases and sharply worsens big picture diseases. Objectively, this is expressed by an increase in symptoms of intoxication, the appearance of chest pain, coughing, followed by the release of bloody sputum. Physical data make it possible to diagnose lobular, less often pseudolobar pneumonia. The course of the disease during treatment can be benign, with a slow recovery. The addition of pneumonia to low-infectious forms of plague makes patients the most dangerous epidemiologically, so each such patient must be identified and isolated.

Some authors distinguish the intestinal form separately, but most clinicians tend to consider intestinal symptoms (severe abdominal pain, profuse mucous-bloody stool, bloody vomiting) as manifestations of the primary or secondary septic form.

With repeated cases of the disease, as well as with plague in people who have been vaccinated or received chemoprophylaxis, all symptoms begin and develop gradually and are more easily tolerated. In practice, such conditions are called “minor” or “outpatient” plague.

Complications of the plague

There are specific complications: ITS, cardiopulmonary failure, meningitis, thrombohemorrhagic syndrome, which lead to the death of patients, and nonspecific complications caused by endogenous flora (phlegmon, erysipelas, pharyngitis, etc.), which are often observed against the background of improvement of the condition.

Mortality and causes of death

In the primary pulmonary and primary septic form without treatment, mortality reaches 100%, most often by the 5th day of illness. In the bubonic form of plague, the mortality rate without treatment is 20–40%, which is due to the development of a secondary pulmonary or secondary septic form of the disease.

Diagnosis of plague

Clinical diagnosis

Clinical and epidemiological data allow one to suspect the plague: severe intoxication, the presence of an ulcer, bubo, severe pneumonia, hemorrhagic septicemia in persons located in the natural focal zone for the plague, living in places where epizootics (deaths) among rodents were observed or there is an indication of registered cases of illness. Every suspicious patient should be examined.

Specific and nonspecific laboratory diagnostics

The blood picture is characterized by significant leukocytosis, neutrophilia with a shift to the left and an increase in ESR. Protein is found in the urine. During X-ray examination of organs chest in addition to enlargement of the mediastinal lymph nodes, you can see focal, lobular, less often pseudolobar pneumonia, and in severe cases - RDS. In the presence of meningeal signs (stiff neck muscles, positive Kernig's sign), a spinal puncture is necessary. In the CSF, three-digit neutrophilic pleocytosis, a moderate increase in protein content and a decrease in glucose levels are more often detected. For specific diagnostics, bubo punctate, ulcer discharge, carbuncle, sputum, nasopharyngeal smear, blood, urine, feces, CSF, and sectional material are examined. The rules for collecting material and its transportation are strictly regulated by the International Health Regulations. The material is collected using special dishes, containers, and disinfectants. The staff works in anti-plague suits. A preliminary conclusion is given on the basis of microscopy of smears stained with Gram, methylene blue, or treated with a specific luminescent serum. Detection of ovoid bipolar rods with intense staining at the poles (bipolar staining) suggests a diagnosis of plague within an hour. For final confirmation of the diagnosis, isolation and identification of the culture, the material is sown on agar in a Petri dish or in broth. After 12–14 hours, characteristic growth appears in the form of broken glass (“lace”) on agar or “stalactites” in the broth. The final identification of the culture is made on the 3rd–5th day.

The diagnosis can be confirmed by serological studies of paired sera in the RPGA, but this method has a secondary diagnostic value. Pathological changes in intraperitoneally infected mice and guinea pigs are studied after 3–7 days, with the inoculation of biological material. Similar methods of laboratory isolation and identification of the pathogen are used to identify plague epizootics in nature. For research, materials are taken from rodents and their corpses, as well as fleas.

Differential diagnosis

The list of nosologies with which differential diagnosis must be carried out depends on clinical form diseases. The cutaneous form of plague is differentiated from the cutaneous form of anthrax, bubonic - from the cutaneous form of tularemia, acute purulent lymphadenitis, sodoku, benign lymphoreticulosis, venereal granuloma; pulmonary form - from lobar pneumonia, pulmonary anthrax. The septic form of plague must be distinguished from meningococcemia and other hemorrhagic septicemia. Diagnosis of the first cases of the disease is especially difficult. Great importance have epidemiological data: stay in foci of infection, contact with rodents with pneumonia. It should be borne in mind that early use of antibiotics modifies the course of the disease. Even the pneumonic form of plague in these cases can be benign, but the patients still remain infectious. Considering these features, in the presence of epidemic data, in all cases of diseases occurring with high fever, intoxication, lesions of the skin, lymph nodes and lungs, plague should be excluded. In such situations, it is necessary to conduct laboratory tests and involve anti-plague service specialists. The criteria for differential diagnosis are presented in the table (Tables 17-23).

Table 17-23. Differential diagnosis plague

Indications for consultation with other specialists

Consultations are usually carried out to clarify the diagnosis. If the bubonic form is suspected, a consultation with a surgeon is indicated; if the pulmonary form is suspected, a consultation with a pulmonologist is indicated.

An example of a diagnosis formulation

A20.0. Plague, bubonic form. Complication: meningitis. Heavy current.
All patients with suspected plague are subject to emergency hospitalization on special transport to an infectious diseases hospital, in a separate box, in compliance with all anti-epidemic measures. Personnel caring for plague patients must wear a protective anti-plague suit. Household items in the ward and the patient's excretions are subject to disinfection.

Treatment of plague

Mode. Diet

Bed rest during the febrile period. There is no special diet provided. It is advisable to have a gentle diet (table A).

Drug therapy

Etiotropic therapy should be started if plague is suspected, without waiting for bacteriological confirmation of the diagnosis. It includes the use of antibacterial drugs. When studying natural strains of the plague bacterium in Russia, no resistance to common antimicrobial drugs. Etiotropic treatment is carried out according to approved schemes (Tables 17-24–17-26).

Table 17-24. Scheme for the use of antibacterial drugs in the treatment of bubonic plague

Table 17-25. Scheme for the use of antibacterial drugs in the treatment of pneumonic and septic forms of plague

** Used to treat plague affecting the central nervous system.

Table 17-26. Schemes for the use of combinations of antibacterial drugs in the treatment of pneumonic and septic forms of plague

* There are injection forms of the drug for parenteral administration.

In severe cases, it is recommended to use compatible combinations during the first four days of illness antibacterial agents in the doses indicated in the regimens. In the following days, treatment is continued with one drug. For the first 2–3 days, the medications are administered parenterally, and subsequently switch to oral administration.

Along with specific treatment, pathogenetic treatment is carried out aimed at combating acidosis, cardiovascular failure and DN, microcirculation disorders, cerebral edema, and hemorrhagic syndrome.

Detoxification therapy consists of intravenous infusions colloidal (reopolyglucin, plasma) and crystalloid solutions (glucose 5–10%, polyionic solutions) up to 40–50 ml/kg per day. The previously used anti-plague serum and specific gamma globulin turned out to be ineffective during the observation process, and at present they are not used in practice, nor is the plague bacteriophage used. Patients are discharged after complete recovery (for the bubonic form no earlier than the 4th week, for the pulmonary form - no earlier than the 6th week from the day of clinical recovery) and three negative result, obtained after culture of bubo punctate, sputum or blood, which is carried out on the 2nd, 4th, 6th days after cessation of treatment. After discharge, medical observation is carried out for 3 months.