Plague is viral or bacterial. Etiology and pathogenesis. Diagnosis of bubonic plague

Plague is one of the most dangerous infectious diseases with a severe course, in which The lymph nodes, internal organs with development severe sepsis. The disease is highly contagious and has a high fatality rate. In world history, three pandemics of the plague or "black death" are described, during which more than 100 million people died. The plague agent was also used as a biological weapon during wars. Plague is a severe disease that spreads rapidly and infects everyone who meets on the way. To date, the level of plague has decreased significantly, but still the disease continues to affect people every day.

Etiology and pathogenesis of the disease

The causative agent of plague is the plague bacillus or Yersinia pestis. The bacterium is stable in the external environment; for many years it retains its viability in infected corpses and sputum. But it quickly dies at a temperature of 55-60 ° C.

Fleas Xenopsylla cheopis are the main source of the plague bacillus. When a flea bites a plague-stricken animal, the pathogen enters its body and remains there. A flea bites a healthy animal or person, infecting it with the plague. Rodents are carriers of these fleas. They multiply rapidly and move, spreading a large number of infected fleas, and infecting a large number of people and animals.

The main mechanism of transmission of the disease is transmissible. Also, the pathogen is transmitted by airborne, alimentary and contact routes.

In humans, the portals of entry for plague infection are damaged skin, mucous membranes, digestive tract. A person is very susceptible to the plague, so it becomes infected immediately. After the plague bacillus enters the body, a small papule with blood contents forms at the site of the flea bite, which quickly passes. The causative agent from the bite enters the bloodstream, and then settles in the lymph nodes. In the lymph nodes, Yersinia multiplies, inflammation develops. Without treatment, the pathogen from the lymph nodes enters the bloodstream again with the development of bacteremia and settles on other organs, which further leads to severe sepsis.

Reasons for the development of plague

Reservoirs of Yersinia pestis, such as burials of plague patients, are the main reason for its development. The causative agent retains pathogenic properties for decades. Therefore, the opening of such burials is the main reason for the development of outbreaks of plague today. Also, the causes of the development of the disease include:

contact with animals sick with plague;
flea, tick bites;
excavations of old graves, historical excavations;
contact with plague-stricken people.

These factors significantly contribute to the rapid spread of the plague pathogen, increasing the number of cases. Therefore, it is possible to identify risk groups that are more prone to plague infection. This:

veterinarians;
archaeologists;
health workers;
farmers, foresters, zookeepers, field workers;
employees of scientific laboratories who work with rodents.

Such individuals often come into contact with animals that carry plague or infected fleas, as well as with people who are sick with plague.

Doctor's advice. The main carriers of the plague are rats. Try to avoid any contact with them. It is also necessary to control the presence of rats and mice in the basements in residential buildings, and immediately eliminate their holes

Disease classification

Plague is divided into the following types depending on the extent of the pathological process:

local;
generalized;
externally disseminated.

There are such forms of plague depending on the affected organs:

bubonic;
pulmonary:
skin;
intestinal;
mixed.

Sepsis is a severe complication of any form of plague. It leads to the circulation of a large number of pathogens in the blood and the defeat of all organs in the body. It is difficult to cure such sepsis. It often leads to death.

Clinical picture of plague and complications

The incubation period lasts 1-7 days, after which symptoms begin to appear. The disease begins abruptly, with the onset of severe fever, chills, intoxication and general weakness. The symptoms progress rapidly and are accompanied by pain in the muscles and joints. Such patients are often agitated, hallucinating or delusional. With the progression of the disease in people, coordination is disturbed, and excessive excitement is replaced by apathy. Such patients most often cannot even get out of bed.

An important symptom of the plague is the "chalky tongue". It becomes dry, thick with a large layer white plaque. The pressure in such patients is usually low, and a decrease in the amount of urine up to its absence is also characteristic.

The clinic of the disease may vary depending on the form. For example, for bubonic - damage to the lymph nodes is characteristic. The affected lymph nodes increase significantly in volume, protrude above the skin. They are painful and hot to the touch, soldered to the surrounding tissues.

Skin plague is characterized by the appearance of pustules with bloody contents. Over time, the pustules open themselves and in their place appear ulcers with jagged black edges and a yellow bottom. In the future, the bottom is covered with a scab and also acquires a black color. Such ulcers appear all over the body and take a long time to heal with the formation of scars.

With intestinal plague, sharp pains in the abdomen appear, which are not removed by anything. There is vomiting and diarrhea with blood, frequent urge to defecate.

In the pulmonary form, patients develop a severe cough, sputum with blood. Cough is not stopped by anything, difficulty in breathing is added to it.

All forms of plague are characterized by severe fever, intoxication, and a rapid increase in symptoms.

The most severe complication of plague is sepsis. It is typical for him sharp deterioration conditions, fever, chills, hemorrhagic rash all over the body. Often, pulmonary or intestinal bleeding can begin. Sepsis affects all organs, primarily the brain, heart, and kidneys.

Which doctors to contact and the prognosis of the disease

Patients can turn to local therapists, pulmonologists or dermatovenereologists. Or such patients cause ambulance at serious condition. If plague is suspected, all patients will be referred to an infectious disease specialist. Plague is treated in a hospital in separate closed blocks, entry to which is prohibited to outsiders.

Prognosis for life with the right and timely treatment favorable. Maybe full recovery at early diagnosis plague. But there is a high risk of death with late initiation of therapy.

Important! When the first symptoms of the disease appear, consult a doctor as soon as possible. Plague is a fleeting disease that cannot be cured on its own, therefore life will depend on the time of going to the hospital

Plague diagnosis

For accurate diagnosis a detailed history of the disease is collected from the patient and a complete examination is performed. Most often, such events are enough to suspect the plague and isolate the patient.

To confirm the diagnosis, it is necessary to isolate the pathogen from the body of the victim. To do this, use the patient's sputum, pus from ulcers, the contents of the affected lymph nodes and blood.

To determine the pathogen in the biological materials of the patient, reactions such as ELISA, PCR, indirect hemagglutination reaction are used. The purpose of such studies is to use antibodies to detect the presence of Yersinia antigens in the human body. The presence of antibodies to the plague bacillus in the patient's blood is also determined.

Treatment methods for the disease

Patients are isolated from others. If plague is suspected, the doctor stops accepting other patients, the hospital is closed for the duration of the diagnosis. The doctor who suspected the plague sends an emergency message to the epidemiological station. A plague patient is transported by ambulance to the infectious diseases hospital. In the hospital, they are placed in separate boxes with a separate entrance from the street, as well as a separate bathroom.

A doctor who has been in contact with a plague patient treats himself with a streptomycin solution to prevent the plague. Offices are also subject to disinfection. They enter the box to the plague patient in special clothes, which are put on immediately before entering.

Also disinfection of the room where the patient lives, a detailed examination of contact persons is carried out.

Etiotropic treatment of plague - antibiotics. Most often, Streptomycin or Tetracycline and their derivatives are used. Also use symptomatic therapy. Antipyretics are administered to reduce fever. To reduce the symptoms of intoxication, the patient is given droppers with saline solutions, rheosorbilact, gemodez, albumin solutions, etc. Plasmapheresis is also performed. Apply surgical treatment ulcers on the skin, apply sterile dressings. If necessary, patients are given painkillers, anti-inflammatory drugs and stop bleeding.

Plague Prevention

Today, in most countries, the causative agent of the plague is absent. Therefore, the main protection measure is to prevent the importation of the pathogen from dangerous this disease countries. These measures include:

training of people who travel to epidemiological foci of plague;
specific vaccination against plague of persons who live in unfavorable zones, persons who travel to these zones;
inspection of persons coming from unfavorable epidemic zones for plague.

Other important preventive measures include:

isolation of plague patients;
disinfection of premises and examination of contact persons;
elimination of rat and mouse nests.

These measures do not provide one hundred percent protection against the plague. Therefore, it is important to protect your health by observing simple rules of personal hygiene. Remember, your health is only in your hands.

Back in the ancient world, few diseases caused the same panic and destruction as the bubonic plague. This terrible bacterial infection usually spread by rats and other rodents. But when it entered the human body, it quickly spread throughout the body and often proved fatal. Death could come in a matter of days. Let's take a look at six of the most infamous outbreaks of this disease.

Justinian I is often cited as the most powerful Byzantine emperor, but his reign coincided with one of the first well-documented outbreaks of the plague. The pandemic is thought to have originated in Africa and then spread to Europe via infected rats on merchant ships. The plague reached the Byzantine capital of Constantinople in 541 AD and was soon claiming 10,000 lives a day. This led to unburied bodies being piled inside buildings and even outdoors.

According to the ancient historian Procopius, the victims showed many of the classic symptoms. bubonic plague, including sudden rise temperature and swollen lymph nodes. Justinian also fell ill, but he was able to recover, which cannot be said about the third part of the inhabitants of Constantinople who were not so lucky. Even after the plague had subsided in Byzantium, it continued to appear in Europe, Africa and Asia for several more years, causing massive famine and devastation. It is believed that at least 25 million people died, but the actual number could be much higher.

In 1347, the disease again invaded Europe from the East, most likely along with Italian sailors who were returning home from the Crimea. As a result, the Black Death tore apart the entire continent for half a decade. Entire cities were decimated and people spent most of their time trying to bury all the dead in mass graves. Medieval doctors tried to fight the disease with bloodletting and other crude methods, but most people were sure that this was God's punishment for their sins. Some Christians even blamed the Jews for everything and began mass pogroms. The Black Death subsided in the West around 1353, but not before taking 50 million people with it—more than half the population of Europe. While the pandemic wreaked havoc across the continent, some historians believe the labor shortage it caused was a boon for the lower working classes.

Even after the Black Death receded, the bubonic plague continued to rear its ugly head in Europe from time to time for several more centuries. One of the most devastating outbreaks began in 1629, when troops taking part in the Thirty Years' War brought the infection to the Italian city of Mantua. Over the next two years, the plague spread throughout the countryside, but also affected such big cities like Verona, Milan, Venice and Florence. In Milan and Venice, city officials quarantined the sick and completely burned their clothes and possessions to prevent the spread of the disease.

The Venetians even banished some of the plague victims to the islands of the neighboring lagoon. These brutal measures may have helped contain the disease, but up to that time 280,000 people had died, including more than half of the inhabitants of Verona. The Republic of Venice lost a third of its population - 140 thousand people. Some scholars argue that this outbreak undermined the strength of the city-state, leading to its decline as a major player on the world stage.

Plague besieged London several times during the 16th and 17th centuries, but most famous case happened in 1665-1666. It first arose in the London suburb of St. Giles, and then spread to the dirty quarters of the capital. The peak occurred in September 1665, when 8,000 people died every week. Rich people, including King Charles II, fled to the villages, and the main victims of the plague were poor people. As the disease spread, the authorities in London tried to keep the infected in their homes, which were marked with a red cross. Before the outbreak subsided in 1666, died, according to different estimates, from 75 to 100 thousand people. Later that year, London faced another tragedy when the Great Fire destroyed much of the city's inner city.

Last in medieval Europe A major outbreak of plague began in 1720 in the French port city of Marseille. The disease arrived on a merchant ship that picked up infected passengers on a trip to the Middle East. The ship was quarantined, but its owner, who also happened to be Marseille's deputy mayor, persuaded officials to let him unload the goods. The rats that lived in it soon spread throughout the city, which caused an epidemic. People were dying by the thousands, and the piles of bodies on the street were so large that the authorities forced the prisoners to dispose of them. In neighboring Provence, a "plague wall" was even built to contain the infection, but it also spread to the south of France. The disease finally disappeared in 1722, but by that time about 100 thousand people had died.

The Plague of Justinian and the Black Death are considered to be the first two pandemics. The most recent, the so-called Third Pandemic, broke out in 1855 in the Chinese province of Yunnan. Over the next few decades, the disease spread across the globe, and by the early 20th century, infected rats on ships had carried it across all six continents. Worldwide, this outbreak killed 15 million people before it was eradicated in 1950. Most casualties were in China and India, but there were also scattered cases from South Africa to America. Despite heavy casualties, the Third Pandemic led to several breakthroughs in medical understanding of the disease. In 1894, Hong Kong physician Alexander Yersin determined which bacilli were causing the disease. A few years later, another doctor finally confirmed that the flea bites carried by the rats were main reason spread of infection among humans.

plague doctor in the middle ages

For more than a hundred years, people have associated plague with a special disease that claims the lives of millions of people. Everyone knows the damaging ability of the causative agent of this disease and its lightning-fast spread. Everyone knows about this disease, it is so rooted in the human mind that everything negative in life is associated with this word.

What is plague and where does the infection come from? Why does it still exist in nature? What is the causative agent of the disease and how is it transmitted? What are the forms of the disease and symptoms? What is the diagnosis and how is the treatment carried out? Thanks to what kind of prevention in our time it is possible to save billions of human lives?

What is plague

Experts say that plague epidemics were mentioned not only in historical reference books, but also in the Bible. Cases of the disease were regularly recorded on all continents. But of greater interest are not epidemics, but pandemics or outbreaks of infection that are widespread throughout almost the entire territory of the country and cover neighboring ones. In the entire history of the existence of people, they counted three.

The first outbreak of plague or pandemic occurred in the VI century in Europe and the Middle East. During its existence, the infection has claimed the lives of more than 100 million people.
The second case, when the disease covered a significant territory, was noted in Europe, from where it reached from Asia in 1348. At this time, more than 50 million people died, and the pandemic itself is known in history as the "plague - black death." She did not bypass the territory of Russia.
The third pandemic raged at the end of the 19th century in the East, mainly in India. An outbreak began in 1894 in Canton and Hong Kong. A large number of deaths have been recorded. Despite all the precautions from the local authorities, the number of deaths exceeded 87 million.

But it was during the third pandemic that it was possible to carefully examine the dead people and identify not only the source of the infection, but also the carrier of the disease. The French scientist Alexandre Yersin found that a person becomes infected from sick rodents. Several decades later, created effective vaccine against the plague, although this did not help humanity completely get rid of the disease.

Even in our time, isolated cases of plague are recorded in Russia, Asia, the USA, Peru, and Africa. Every year, doctors discover several dozen cases of the disease in various regions, and the number of deaths ranges from one to 10 people, and this can be considered a victory.

Where is the plague found now?

The centers of infection in our time are not marked in red on the usual tourist map. Therefore, before traveling to other countries, it is better to consult an infectious disease specialist where plague is still found.

According to experts, this disease has not yet been completely eradicated. In which countries can you get plague?

Isolated cases of the disease occur in the United States and Peru.
Plague in Europe was practically not registered several recent years, but Asia has not been spared by the disease. Before visiting China, Mongolia, Vietnam and even Kazakhstan, it is better to get vaccinated.
On the territory of Russia, it is also better to play it safe, because several cases of plague are recorded here every year (in Altai, Tyva, Dagestan) and it borders on countries that are dangerous for infection.
Africa is considered a dangerous continent from the point of view of epidemiology, most of today's severe infections can be contracted here. Plague is no exception; isolated cases of the disease have been recorded here over the past few years.
There is an infection on individual islands. For example, just two years ago, a plague struck several dozen people in Madagascar.

The last hundred years of plague pandemics have not been observed, but the infection has not been completely eradicated.

It has long been no secret that many of the most dangerous infections, which include the plague, are being used by the military as biological weapons. During the Second World War in Japan, scientists brought out a special type of pathogen. In terms of its ability to infect people, it surpassed natural pathogens tenfold. And no one knows how the war could have ended if Japan had used this weapon.

Although plague pandemics last hundred have not been registered for years - completely eliminate bacteria, disease-causing, failed. There are natural sources of plague and anthropurgic, that is, natural and artificially created in the process of life.

Why is infection considered especially dangerous? Plague is a disease high level lethality. Prior to the creation of the vaccine, and this happened in 1926, mortality from various kinds plague was at least 95%, that is, only a few survived. Now lethality does not exceed 10%.

plague agent

The causative agent of the infection is yersinia pestis (plague bacillus), a bacterium of the genus Yersinia, which is part of a large family of enterobacteria. To survive in natural conditions This bacterium had to adapt for a long time, which led to the peculiarities of its development and vital activity.

Grows on simple available nutrient media.
It happens in different shapes - from filiform to spherical.
The plague bacillus in its structure contains more than 30 types of antigens that help it survive in the body of the carrier and humans.
Resistant to environmental factors, but instantly dies when boiled.
The plague bacterium has several pathogenicity factors - these are exo and endotoxins. They lead to damage to organ systems in the human body.
You can fight bacteria in the external environment with the help of conventional disinfectants. Antibiotics also kill them.

Plague transmission routes

Not only humans are affected by this disease, there are many other sources of infection in nature. The sluggish variants of the plague pose a great danger, when the affected animal can overwinter, and then infect others.

Plague is a disease with natural foci that affects, in addition to humans and other creatures, for example, domestic animals - camels and cats. They get infected from other animals. To date, more than 300 species of bacterial carriers have been identified.

Under natural conditions, the natural carrier of the plague pathogen are:

gophers;
marmots;
gerbils;
voles and rats;
Guinea pigs.

In urban environments, special types of rats and mice are a reservoir of bacteria:

pasyuk;
gray and black rat;
Alexandrovskaya and Egyptian view rats.

The carrier of plague in all cases are fleas. Human infection occurs when this arthropod bites, when an infected flea, not finding a suitable animal, bites a person. Just one flea in its life cycle can infect about 10 people or animals. The susceptibility to the disease in humans is high.

How is the plague transmitted?

Transmissible or through the bites of an infected animal, mainly fleas. This is the most common way.
Contact, which is infected during the cutting of carcasses of sick domestic animals, as a rule, these are camels.
Despite the fact that the primacy transmission path transmission of plague bacteria, alimentary also plays an important role. A person becomes infected while eating food contaminated with the pathogen.
The methods of penetration of bacteria into the human body during plague include the aerogenic route. While coughing or sneezing, a sick person easily infects everyone around them, so they need to be kept in a separate box.

Plague pathogenesis and its classification

How does the causative agent of plague behave in the human body? The first clinical manifestations of the disease depend on the way bacteria enter the body. Therefore, there are different clinical forms of the disease.

Having penetrated into the body, the pathogen with the blood flow penetrates into the nearest lymph nodes, where it remains and safely multiplies. It is here that the first local inflammation of the lymph nodes occurs with the formation of a bubo, due to the fact that blood cells cannot fully destroy bacteria. Damage to the lymph nodes leads to a decrease protective functions organism, which contributes to the spread of the pathogen in all systems.

In the future, Yersinia affects the lungs. In addition to infection with plague bacteria of the lymph nodes and internal organs, blood poisoning or sepsis occurs. This leads to numerous complications and changes in the heart, lungs, kidneys.

What are the types of plague? Doctors distinguish two main types of the disease:

pulmonary;
bubonic.

They are considered the most common variants of the disease, although conditionally, because bacteria do not affect any particular organ, but gradually in inflammatory process the whole human body is involved. According to the degree of severity, the disease is divided into mild subclinical course, moderate and severe.

plague symptoms

Plague is an acute natural focal infection caused by Yersinia. It is characterized by such clinical signs as severe fever, damage to the lymph nodes and sepsis.

Any form of the disease begins with common symptoms. The incubation period of the plague lasts at least 6 days. The disease is characterized acute onset.

The first signs of plague in humans are as follows:

chills and almost lightning-fast increase in body temperature up to 39–40 ºC;
pronounced symptoms of intoxication - headaches and muscle pain, weakness;
dizziness;
damage to the nervous system of varying severity - from stunning and lethargy to delirium and hallucinations;
the patient has impaired coordination of movements.

A typical appearance of a sick person is characteristic - a reddened face and conjunctiva, dry lips and a tongue that is enlarged and lined with a white thick coating.

Due to the enlargement of the tongue, the speech of the plague patient becomes illegible. If the infection is in severe form- a person's face is puffy with a blue tint or cyanotic, on the face an expression of suffering and horror.

Symptoms of bubonic plague

The name of the disease itself comes from the Arabic word "jumba", which means bean or bubo. That is, it can be assumed that the first clinical sign The "black death" that our distant ancestors described was the enlargement of the lymph nodes, resembling the appearance of beans.

How is bubonic plague different from other variants of the disease?

A typical clinical symptom of this type of plague is bubo. What does he represent? - this is a pronounced and painful enlargement of the lymph nodes. As a rule, these are single formations, but in very rare cases their number increases to two or more. The plague bubo is more often localized in the axillary, inguinal and cervical region.
Even before the appearance of bubo, a sick person develops soreness so pronounced that one has to take a forced position of the body to alleviate the condition.
Another clinical symptom of bubonic plague is that the smaller the size of these formations, the more pain they cause when touched.

How are buboes formed? This is a long process. It all starts with the onset of pain at the site of formation. Then the lymph nodes increase here, they become painful to the touch and soldered with fiber, a bubo is gradually formed. The skin over it is tense, painful and becomes intensely red. Within about 20 days, the bubo resolves or reverses.

There are three options for the further disappearance of the bubo:

long-term complete resorption;
opening;
sclerosis.

V modern conditions with the right approach to the treatment of the disease, and most importantly, with timely therapy, the number of deaths from bubonic plague does not exceed 7-10%.

Symptoms of pneumonic plague

The second most common variant of the plague is its pneumonic form. This is the most severe variant of the development of the disease. There are 3 main periods of development of pneumonic plague:

elementary;
peak period;
soporous or terminal.

In recent times, it was this type of plague that killed millions of people, because the mortality rate from it is 99%.

The symptoms of pneumonic plague are as follows.

More than 100 years ago, the pneumonic form of plague ended in death in almost 100% of cases! Now the situation has changed, which is undoubtedly due to the correct treatment tactics.

How other forms of plague proceed

In addition to the two classic variants of the course of the plague, there are other forms of the disease. As a rule, this is a complication of the underlying infection, but sometimes they occur as primary independent ones.

Primary septic form. The symptoms of this type of plague are slightly different from the two variants described above. The infection develops and proceeds rapidly. The incubation period is shortened and lasts no more than two days. Heat, weakness, delirium and arousal - these are not all signs of a violation of the state. Inflammation of the brain and infectious-toxic shock develops, then coma and death. In general, the disease lasts no more than three days. In relation to this type of disease, the prognosis is unfavorable, recovery almost never occurs.
An erased or mild course of the disease is observed with a skin variant of the plague. The pathogen enters the human body through broken skin. At the site of the introduction of the plague pathogen, changes are observed - the formation of necrotic ulcers or the formation of a boil or carbuncle (this is inflammation of the skin and surrounding tissue around the hair with areas of necrosis and pus release). Ulcers heal for a long time and a scar gradually forms. The same changes may appear as secondary in bubonic or pneumonic plague.

Plague diagnosis

The first stage in determining the presence of infection is epidemic. But it is easy to make a diagnosis this way when there are several cases of the disease with the presence of typical clinical symptoms in patients. If the plague has not been seen in a given area for a long time, and the number of cases is calculated in units, the diagnosis is difficult.

In the case of the onset of infection, one of the first steps in determining the disease is the bacteriological method. If plague is suspected, work with biological material to detect the pathogen is carried out in special conditions, because the infection spreads easily and quickly in the environment.

Almost any biological material is taken for research:

sputum;
blood;
puncture buboes;
examine the contents of ulcerative skin lesions;
urine;
vomit masses.

Almost everything that the patient secretes can be used for research. Since the plague in humans is severe and the person is very susceptible to infection, the material is taken in special clothes, and inoculation on nutrient media in equipped laboratories. Animals infected with bacterial cultures die in 3–5 days. In addition, when using the method of fluorescent antibodies, bacteria glow.

Additionally, serological methods for the study of plague are used: ELISA, RNTGA.

Treatment

Any patient with suspected plague is subject to immediate hospitalization. Even in the case of the development of mild forms of infection, a person is completely isolated from others.

In the distant past, the only method of treating the plague was cauterization and processing of buboes, their removal. In an attempt to get rid of the infection, people used only symptomatic methods, but to no avail. After identifying the pathogen and creating antibacterial drugs decreased not only the number of patients, but also complications.

What is the treatment for this disease?

The basis of treatment is antibiotic therapy, tetracycline antibiotics are used in the appropriate dose. At the very beginning of treatment, the maximum daily doses of drugs are used, with their gradual decrease to the minimum in case of normalization of temperature. Before starting treatment, the sensitivity of the pathogen to antibiotics is determined.
An important milestone The treatment for plague in humans is to carry out detoxification. Patients are injected saline solutions.
Applies symptomatic treatment: use diuretics in case of fluid retention, use hormonal substances.
Use therapeutic anti-plague serum.
Along with the main treatment, supportive therapy is used - heart drugs, vitamins.
In addition to antibiotics, prescribed local medicines from the plague. Plague buboes are treated with antibiotics.
In the case of the development of a septic form of the disease, plasmapheresis is used daily - this is a complex procedure for cleaning the blood of a sick person.

After the end of treatment, after approximately 6 days, conduct a control study of biological materials.

Plague Prevention

The invention of antibacterial drugs would not solve the problem of the emergence and spread of pandemics. It's just effective way to cope with the disease that has already arisen and the prevention of its most formidable complication - death.

So how did you defeat the plague? - after all, isolated cases per year without declared pandemics and the minimum number of deaths after an infection can be considered a victory. A big role belongs proper prevention illness. And it began the moment the second pandemic arose, back in Europe.

In Venice, after the second wave of the spread of the plague, back in the 14th century, while only a quarter of the population remained in the city, the first quarantine measures were introduced for arrivals. Ships with cargo were kept in the port for 40 days and the crew was monitored to prevent the spread of infection so that it did not enter from other countries. And it worked, no new cases of infection were noted, although the second plague pandemic had already claimed most of the population of Europe.

How is infection prevention carried out today?

Even if isolated cases of plague occur in any country, all those arriving from there are isolated and observed for six days. If a person has some signs of the disease, then prophylactic doses of antibacterial drugs are prescribed.
The prevention of plague includes the complete isolation of patients with suspected infection. People are not only placed in separate closed boxes, but in most cases they try to isolate the part of the hospital where the patient is located.
The State Sanitary and Epidemiological Service plays an important role in preventing the occurrence of infection. They annually monitor the outbreaks of plague, take water samples in the area, examine animals that may be natural reservoir.
In the foci of the development of the disease, the destruction of plague carriers is carried out.
Measures to prevent plague in the outbreaks of the disease include sanitary and educational work with the population. They explain the rules of behavior for people in case of another outbreak of infection and where to go first.

But even all of the above was not enough to defeat the disease if the plague vaccine had not been invented. It was from the moment of its creation that the number of cases of the disease has sharply decreased, and there have been no pandemics for more than 100 years.

Vaccination

Today to fight the plague, apart from the general preventive measures, apply more effective methods, which helped to forget about the "black death" for a long time.

In 1926, the Russian biologist V. A. Khavkin invented the world's first plague vaccine. From the moment of its creation and the beginning of universal vaccination in the foci of the appearance of infection, plague epidemics have remained far in the past. Who is vaccinated and how? What are its pros and cons?

Nowadays, a lyophilisate or a live dry vaccine against plague is used, this is a suspension of live bacteria, but a vaccine strain. The drug is diluted immediately before use. It is used against the causative agent of bubonic plague, as well as pulmonary and septic forms. This is a universal vaccine. The drug diluted in a solvent is injected different ways, which depends on the degree of dilution:

apply it subcutaneously with a needle or needleless method;
skin;
intradermally;
use the plague vaccine even by inhalation.

Prevention of the disease is carried out for adults and children from the age of two.

Indications and contraindications for vaccination

Plague vaccination is done once and it protects for only 6 months. But not every person is vaccinated, certain groups of the population are subject to prevention.

To date, this vaccination has not been included as mandatory in national calendar vaccinations, it is done only according to strict indications and only to certain citizens.

Vaccination is given to the following categories of citizens:

to all who live in epidemically dangerous areas, where the plague occurs in our time;
healthcare workers whose professional activity is directly related to work in "hot spots", that is, in places where the disease occurs;
vaccine developers and laboratory workers in contact with bacterial strains;
preventive vaccination is given to people with high risk of infection, working in the foci of infection - these are geologists, workers of anti-plague institutions, shepherds.

It is impossible to carry out prophylaxis with this drug for children under two years of age, pregnant and lactating women, if a person has already had the first symptoms of plague, and everyone who has had a reaction to a previous vaccine administration. There are practically no reactions and complications to this vaccination. Of the minuses of such prevention, one can note its short effect and possible development diseases after vaccination, which is extremely rare.

Can plague occur in vaccinated people? Yes, this also happens if an already sick person is vaccinated or the vaccine turned out to be of poor quality. This type of disease is characterized by a slow course with sluggish symptoms. The incubation period exceeds 10 days. The condition of the patients is satisfactory, so it is almost impossible to suspect the development of the disease. Diagnosis is facilitated with the appearance of a painful bubo, although there is no inflammation of the tissues and lymph nodes around. In case of delayed treatment or its complete absence further development disease fully corresponds to its usual classical course.

Plague is currently not a sentence, but another dangerous infection that can be dealt with. And although in the recent past, all people and health workers were afraid of this disease, today, the basis of its treatment is prevention, timely diagnosis and complete isolation of the patient.

a highly contagious bacterial infection with multiple ways transmission and epidemic spread, proceeding with febrile-intoxication syndrome, damage to the lymph nodes, lungs and skin. The clinical course of various forms of plague is characterized by high fever, severe intoxication, agitation, excruciating thirst, vomiting, regional lymphadenitis, hemorrhagic rash, DIC, as well as its specific symptoms (necrotic ulcers, plague buboes, ITSH, hemoptysis). Plague is diagnosed laboratory methods(bakposev, ELISA, RNGA, PCR). Treatment is carried out in conditions of strict isolation: tetracycline antibiotics, detoxification, pathogenetic and symptomatic therapy are indicated.

ICD-10

A20

General information

Plague is an acute infection, transmitted mainly by a transmissible mechanism, manifested by inflammation of the lymph nodes, lungs, and other organs, having a serous-hemorrhagic nature, or proceeding in a septic form. Plague belongs to the group of especially dangerous infections.

Plague belongs to the group of especially dangerous infections. In the past, the Black Death pandemics, as the plague was called, claimed millions of human lives. Three global outbreaks of plague are described in history: in the VI century. in the Eastern Roman Empire ("Justinian plague"); in the 14th century in the Crimea, the Mediterranean and Western Europe; in the end of the 19th century. in Hong Kong. At present, thanks to the development of effective anti-epidemic measures and an anti-plague vaccine, only sporadic cases of infection in natural foci are recorded. In Russia, plague-endemic areas include the Caspian Lowland, Stavropol, the Eastern Urals, Altai, and Transbaikalia.

Exciter characteristic

Yersinia pestis is a non-motile, facultative anaerobic, Gram-negative, rod-shaped bacterium from the genus Enterobacteriaceae. The plague bacillus can remain viable for a long time in the discharge of sick people, corpses (in bubonic pus, Yersinia live up to 20-30 days, in the corpses of people and dead animals - up to 60 days), tolerates freezing. To factors external environment(sunlight, atmospheric oxygen, heating, changing the acidity of the environment, disinfection) this bacterium is quite sensitive.

The reservoir and source of the plague are wild rodents (marmots, voles, gerbils, pikas). In various natural foci, different types of rodents can serve as a reservoir, in urban conditions - mainly rats. Dogs that are resistant to human distemper can serve as a source of pathogen for fleas. In rare cases (with the pneumonic form of plague, or with direct contact with bubonic pus), a person can become a source of infection, fleas can also receive the pathogen from patients with a septic form of plague. Often, infection occurs directly from plague corpses.

The plague is transmitted through a variety of mechanisms, the leading place among which is transmissible. The carriers of the plague pathogen are fleas and ticks of some species. Fleas infect animals that carry the pathogen with migration, also spreading fleas. Humans become infected by rubbing flea excrement into the skin while scratching. Insects remain infective for about 7 weeks (there is evidence of flea contagiousness throughout the year).

Infection with plague can also occur by contact (through damaged skin when interacting with dead animals, butchering carcasses, harvesting skins, etc.), alimentary (when eating the meat of sick animals for food).

People have an absolute natural susceptibility to infection, the disease develops when infected in any way and at any age. Post-infectious immunity is relative, it does not protect against re-infection, however, repeated cases of plague usually occur in a milder form.

Plague classification

Plague is classified according to clinical forms, depending on the predominant symptoms. There are local, generalized and externally disseminated forms. Local plague is subdivided into skin, bubonic and skin-bubonic, generalized plague is primary and secondary septic, externally disseminated form is subdivided into primary and secondary pulmonary, as well as intestinal.

plague symptoms

The incubation period of the plague on average takes about 3-6 days (up to a maximum of 9 days). In mass epidemics or in the case of generalized forms incubation period may be shortened to one or two days. The onset of the disease is acute, characterized by the rapid development of fever, accompanied by tremendous chills, severe intoxication syndrome.

Patients may complain of pain in the muscles, joints, sacral region. There is vomiting (often with blood), thirst (excruciating). From the very first hours, patients are in excited state Perceptual disturbances (delusions, hallucinations) may occur. Coordination is disturbed, intelligibility of speech is lost. Lethargy and apathy occur noticeably less frequently, patients weaken to the point of being unable to get out of bed.

The face of the patients is puffy, hyperemic, the sclera are injected. At severe course hemorrhagic rashes are noted. characteristic feature plague is a "chalky tongue" - dry, thickened, densely covered with bright white bloom. Physical examination shows marked tachycardia, progressive hypotension, dyspnea, and oliguria (up to anuria). In the initial period of the plague, this symptomatic picture observed in all clinical forms of plague.

Skin form manifests itself in the form of a carbuncle in the field of introduction of the pathogen. The carbuncle progresses through the following stages: first, a pustule forms on the hyperemic, edematous skin (pronounced painful, filled with hemorrhagic contents), which, after opening, leaves an ulcer with raised edges and a yellowish bottom. The ulcer tends to grow. Soon, a necrotic black scab forms in its center, quickly filling the entire bottom of the ulcer. After the scab is shed, the carbuncle heals, leaving a rough scar.

bubonic form is the most common form of plague. Buboes are called specifically altered lymph nodes. Thus, with this form of infection, the predominant clinical manifestation purulent lymphadenitis is regional in relation to the area of introduction of the pathogen. Buboes, as a rule, are single, in some cases they can be multiple. Initially, pain is noted in the region of the lymph node, after 1-2 days, enlarged painful lymph nodes are found on palpation, initially dense, with the progression of the process softening to a pasty consistency, merging into a single conglomerate soldered to the surrounding tissues. The further course of the bubo can lead both to its independent resorption and to the formation of an ulcer, an area of sclerosis or necrosis. The peak of the disease lasts for a week, then a period of convalescence begins, and clinical symptoms gradually subsides.

Skin-bubonic form characterized by a combination of skin manifestations with lymphadenopathy. Local forms of plague can progress into a secondary septic and secondary pulmonary form. Clinical course these forms does not differ from their primary counterparts.

Primary septic form develops at lightning speed, after a shortened incubation (1-2 days), is characterized by a rapid increase in severe intoxication, a pronounced hemorrhagic syndrome (numerous hemorrhages in skin, mucous membranes, conjunctiva, intestinal and renal bleeding), the rapid development of infectious-toxic shock. The septic form of the plague without proper timely medical care ends in death.

Primary pulmonary form occurs in the case of an aerogenic route of infection, the incubation period is also reduced, it can be several hours or last about two days. The onset is acute, characteristic of all forms of plague - increasing intoxication, fever. Pulmonary symptoms appear by the second or third day of the disease: there is a strong debilitating cough, first with clear vitreous, later with foamy bloody sputum, there is chest pain, difficulty breathing. Progressive intoxication contributes to the development of acute cardiovascular failure. The outcome of this condition can be stupor and subsequent coma.

intestinal form characterized by intense sharp pains in the abdomen with severe general intoxication and fever, soon joins frequent vomiting, diarrhea . The stool is copious, with impurities of mucus and blood. Often - tenesmus (painful urge to defecate). Given the prevalence of other intestinal infections, at present, the question has not been resolved: is intestinal plague an independent form of the disease that has developed as a result of microorganisms entering the intestine, or is it associated with the activation of the intestinal flora.

Plague diagnosis

Due to the special danger of infection and the extremely high susceptibility to the microorganism, the pathogen is isolated in specially equipped laboratories. The material is taken from buboes, carbuncles, ulcers, sputum and mucus from the oropharynx. It is possible to isolate the pathogen from the blood. Specific bacteriological diagnostics is performed to confirm clinical diagnosis, or, with prolonged intense fever in patients, in an epidemiological focus.

Serological diagnosis of plague can be made using RNGA, ELISA, RNAT, RNAG and RTPGA. It is possible to isolate the DNA of the plague bacillus using PCR. Non-specific methods diagnostics - a blood test, urine (there is a picture of an acute bacterial lesion), with a pulmonary form - an x-ray of the lungs (signs of pneumonia are noted).

plague treatment

Treatment is carried out in specialized infectious diseases departments of the hospital, under conditions of strict isolation. Etiotropic therapy is carried out with antibacterial agents in accordance with clinical form diseases. The duration of the course takes 7-10 days.

In the cutaneous form, co-trimoxazole is prescribed; in the bubonic form, intravenous chloramphenicol with streptomycin is prescribed. Tetracycline antibiotics can also be used. Tetracycline or doxycycline is supplemented with a complex of chloramphenicol with streptomycin for plague pneumonia and sepsis.

Nonspecific therapy includes a complex of detoxification measures (intravenous infusion of saline solutions, dextran, albumin, plasma) in combination with forcing diuresis, agents that improve microcirculation (pentoxifylline). If necessary, cardiovascular, bronchodilator drugs, antipyretic drugs are prescribed.

Plague prognosis

Currently, in the conditions of modern hospitals, when using antibacterial agents Plague mortality is quite low - no more than 5-10%. Early health care, prevention of generalization contribute to recovery without pronounced consequences. In rare cases, transient plague sepsis (fulminant form of plague) develops, which is difficult to diagnose and treat, often ending in a quick death.

Plague Prevention

At present, infection is practically absent in developed countries, so the main preventive actions aimed at preventing the importation of the pathogen from epidemiologically dangerous regions and sanitation of natural foci. Specific prophylaxis consists in vaccination with a live plague vaccine, produced for the population in areas with an unfavorable epidemiological situation (prevalence of plague among rodents, cases of infection of domestic animals) and persons traveling to regions with heightened danger infections.

Identification of a plague patient is an indication for taking urgent action for its isolation. In case of forced contacts with patients, individual prophylaxis means are used - anti-plague suits. Contact persons are observed for 6 days; in case of contact with a patient with pneumonic plague, prophylactic antibiotic therapy is performed. Discharge of patients from the hospital is made no earlier than 4 weeks after clinical recovery and negative tests for bacterioexcretion (with pulmonary form - after 6 weeks).