Plague - Causes, symptoms and treatment. MF.

Plague( "Black Death", Pestis) is a particularly dangerous, acute, natural focal zooanthroponous * bacterial infection, with multiple transmission routes, characterized by a feverish intoxication syndrome, and also a predominant lesion of the skin and lungs.

A brief historical essay: without exaggeration, you can add to the following characteristics the prefix "most" - the oldest, the most dangerous and to this day, beating records on the severity of the current and the highest mortality rate, and also on the level of contagiousness( infectiousness) - in all these points there is practically no plagueequal.
Still absolutely illiterate natives from generation to generation passed on the worldly experience: when the dead rats appeared in the hut, the whole tribe left the terrain, imposing taboos and never returning.

Three major pandemic plagues were recorded in the history of the world:

• In the third century there was the first description in the territories where Libya, Syria and Egypt are now located.

• A pandemic in the 6th century in the Roman Empire until the end of Justinian's rule - the "Justinian pandemic".During this period, thanks to the accumulated experience, 40 days of quarantine were introduced, in order to prevent the spread of infection.
• The end of the 19th century - the third pandemic, the most common in seaports. Also this century became a turning point, because during this period the causative agent of the plague was discovered by the French scientist Yersin in 1894.

For a long time before these pandemics, there were many epidemics that do not count. .. One of the largest was in France, in the 16th century, where one of the most famous psychics, doctors and astrologers - Nostradamus lived. He successfully fought the "black death" with the help of phytotherapy, and his recipe has come down to our days: sawdust of young cypress, Florentine iris, clove, fragrant ayr and woody aloe - with all these ingredients mixed rose petals and from this mixture made tablets "pinkpills. "Unfortunately, his wife and children could not save Nestradamus from the plague. ..

Many cities in which death reigned were burned, and local doctors, trying to help the infected, wore special anti-plague "armor": leather cloak to the heels, maskwith a long nose, various herbs were placed in this bow section and, when inhaled, the heated air caused evaporation of the antiseptic substances contained in the herbs, the inhaled air was practically sterile. This mask was protected by crystal lenses, rags were stuck into the ears, and the mouth cavity was rubbed with raw garlic.

Anti-Plague Suit

It would seem that the era of "antibiotics" will permanently exclude the danger of plague, so they thought for a short time until a genetic mutant of the plague was modeled by the scientist Bacon-an antibiotic-resistant strain. Also, vigilance can not be reduced because there have always been natural foci( territorially aggressive).Social upheavals and economic depression are predisposing factors in the spread of this infection.

Pathogen plague

Pathogen - Yersinia Pestis, looks like an egg-shaped stick, G-, has no spores and flagella, but in the body forms a capsule. On nutrient media gives a characteristic growth: on broth agar - plague stalactites, on dense media, the first 10 h in the form of "broken glass", after 18 h in the form of "lacy handkerchiefs"  and by 40 h "adult colonies" are formed.

Plague causative agent

There are a number of structural characteristics that are constituents of pathogenicity factors:

• Capsule - inhibits the activity of macrophages.
• Drank( small villi) - inhibit phagocytosis and cause the introduction of the pathogen into macrophages.
• Plasmocoagulase( also called coagulase) - leads to plasma clotting and rheology of the blood.
• Neuronidase - provides adhesion to the attachment of the pathogen by releasing its receptors on the surface.
• Specific antigen pH6 - synthesized at a temperature of 36 ° C, and has anti-agonitic and cytotoxic activity.
• Antigens W and V - provide propagation of the pathogen within macrophages.
• Catalyzed activity provided with adenylate cyclase - suppresses oxidative explosion in macrophages, which reduces their protective ability.
• Aminopeptidases - provide proteolysis( cleavage) on the cell surface, inactivation of regulatory proteins and growth factors.
• Pesticin - biologically active components of Y. pestis that inhibit the growth of other members of the genus Yersinia( Yersiniozov).
• Fibrinolysin - provides cleavage of the blood clot, which subsequently aggravates the clotting disorder.
• Hyaluronidase - provides destruction of intercellular bonds, which further facilitates its penetration into the deeper tissues.
• Endogenous purines( the role of their presence is not completely clear, but in the decay they form uric acid, which is potentially toxic).
• Endotoxin is a lipopolysaccharide complex, has toxicity and allergenic effects.
• Rapid growth at a temperature of 36.7-37 ° C - this feature in combination with antifaocytic factors( the above) makes the growth and reproduction of the causative agent of the plague practically unobstructed.
• The ability of the causative agent to sorb( accumulate / collect) hemin( derived from the gemma - the non-protein part of the transporter Fe3 + in the blood) - this property ensures the propagation of the pathogen in the tissues.
• Mouse toxin( lethal = C-toxin) - has cardiotoxic( cardiac damage), hepatotoxic( liver damage) and capillarotoxic effect( disrupts vascular permeability and causes thrombocytopathy).This factor is manifested by the blockade of electrolyte transfer in the mitochondria, ie blockade of the energy depot.

All the pathogenicity( harmfulness) is controlled by genes( there are only 3 of them) - they were influenced by Bacon, modeling an antibiotic-resistant mutant of the plague and thus warned mankind of a moving threat in the face of unreasonable and uncontrolled use of antibiotics.

Stability of plague pathogen:

• Sputum persists for 10 days;
• On linen, clothes and on household items, stained with mucus - for weeks( 90 days);
• In the water - 90 days;
• In buried corpses - up to a year;
• On open warm spaces - up to 2 months;
• In the pus of bubo( enlarged lymph node) - 40 days;
• In soil - 7 months;
• Freezing and thawing, as well as low temperatures - have little effect on the pathogen;

Destructive: direct UVD and disinfectants - cause instant death, at 60 ° C - perishes within 30 minutes, at 100 ° C - death is instantaneous.

Plague refers to natural focal infections, ie there are territorially dangerous in the epidemic relation zones, in the territory of the Russian Federation there are 12 of them: in the North Caucasus, Kabardino-Balkaria, Dagestan, Zabaikayile, Tuva, Altai, Kalmykia, Siberia and Astrakhanregion. Natural centers on a global scale exist on all continents, except Australia: in Asia, Afghanistan, Mongolia, China, Africa and South America.

In addition to natural focal( natural) zones, there are also synanthropic foci( anthropo-uric) - urban, port, ship.
Susceptibility is high, without sexual and age restrictions.

Causes of plague infection

Source and reservoir( keeper) of infection - rodents, laggering, camels, dogs, cats, sick people. The carrier is a flea that retains infectiousness for up to a year. The plague grows in the digestive tube of fleas and forms a "plague block" in its anterior part - a cork of a huge number of pathogens. With a bite, with a reverse current of blood, from this plug the part of bacteria is washed off - so infection occurs.

Ways of infection:

• Transmissible( through flea bites);
• Contact - through damaged skin and mucous membranes when removing skins from infected animals, when slaughtering and cutting carcasses, and also in contact with biological fluids of a sick person;
• Contact-household - through household items infected with biological environments of infected animals / humans;
• Airborne( through the air, from a patient with a pulmonary form of the plague);
• Alimentary - when eating contaminated food.

Symptoms of plague

The incubation period is considered from the moment of introduction of the pathogen up to the first clinical manifestations; during plague this period can last from several hours to 12 days. The causative agent more often penetrates through the affected skin or the mucous membranes of the digestive / respiratory tract. It is captured by tissue macrophages, and part of the pathogen remains in the entrance gates, and some are transferred by macrophages to regional( nearby) lymph nodes. But, while the causative agent dominates phagocytosis and suppresses its action, the organism does not define the pathogen as a foreign object. But phagocytosis is not completely suppressed, some of the pathogens die and, after death, exotoxin is released, and when clinical threshold is reached, its threshold concentration begins.

The period of clinical manifestations begins always sharply, suddenly, from the first symptoms of intoxication in the form of chills, high fever> 39 ° C lasting for 10 days and / or until death, severe weakness, body aches, thirst, nausea, vomitingthe face becomes cyanotic, with dark circles under the eyes - these changes against the background of expression of suffering and horror, called the "mask of the plague."The language is covered with a thick, white touch - "Cretaceous language".There is a standard pathogenetic symptom complex( that is, due to the specific mechanism of the causative agent, 4 standard symptoms are formed in different degrees of manifestation):

• In the place of the entrance gate, a primary focus is formed, which can endure the stage and stop at one of them: spot-papaula-vesicle.
• Increase of regional lymph nodes( formation of "plague bubo") to impressive sizes( ≈black) due to propagation of the pathogen in it and formation of inflammatory-edematous reaction. But often it happens that the process is so lightning that death occurs before the development of the plague bubo.
• ITH( infectious-toxic shock) develops as a result of degranulation of neutrophils( NP) and death of the pathogen with the release of endotoxin. It is characterized by a certain degree of manifestation and the main diagnostic criteria are: changes in the nervous system( state of consciousness) + ↑ or ↓ t ° of the body + hemorrhagic rash( spot rashes in the oropharynx) + hemorrhages in the mucous membranes + disorders of peripheral circulation( cooling, pallor or blueing of the extremities, nasolabial triangle, face) + changes in heart rate and blood pressure( ↓) + change in intracranial pressure( ↓) + formation of renal failure, manifests itself in the form of a lower(acid-base state) in the direction of acidosis
• DIC-syndrome( disseminated intravascular coagulation) is a very serious condition, which is based on disorganization of the coagulating and anticoagulant system. DIC occurs in parallel with the development of ITH and manifests itself ↓ Tp +  ↑ clotting time + ↓ clot contraction reduction + positive procoagulation test.

Clinical forms of the disease:

• localized( cutaneous, bubonic);
• generalized( pulmonary, septic).

The forms of the disease are indicated in the order in which the disease can develop in the absence of treatment.

Cutaneous form : at the entrance gate there are tissue changes( one of 4 standard symptoms), in severe or lightning cases, a flicten( blister) filled with serous-hemorrhagic contents, surrounded by an infiltrative zone with hyperemia and edema can develop. At palpation this formation is painful, and at autopsy an ulcer with black necrosis( a scab) at the bottom is formed - hence the name "black death".This ulcer heals very slowly and leaves scars always after healing and, because of slow healing, secondary bacterial infections are often formed.

Bubonic form : "Plaguebubbon" is an enlarged lymph node, either one, or several. The increase can be from the size of a walnut to an apple, the skin is shiny and red with a cyanotic shade, the consistency is dense, the palpation is painful, the surrounding tissues are not soldered, the boundaries are distinct due to the concomitant periadenitis( inflammation of the circum-lymphatic tissues), on the 4th day the bubon softensand there is a fluctuation( a feeling of excitement or fluctuation when tapping), on day 10 this lymphatic foci is opened and a fistula is formed with expression. This form can lead to both secondary bacterial septic complications and septic plague complications( ie plague bacteremia) with the introduction of a plague agent into any organs and tissues.

Septic form : characterized by the rapid development of INS and DIC-syndrome, the foreground are multiple hemorrhages on the skin and mucous membranes, bleeding in the internal organs. This form is primary - when a massive dose of the pathogen hits, and secondary - in secondary bacterial complications.

The pulmonary form of is most dangerous in the epidemiological sense. The onset of acute, as with any other form, joins and protrudes to the 4 standard clinical symptoms and acts on the first pan pulmonary symptomatology( due to the melting of the walls of the alveoli): a dry cough appears, which becomes productive in 1-2 days - sputum first frothy, vitreous, transparent and in consistency like water, and then it becomes purely bloody, with an innumerable amount of irritation. This form, as well as the septic form, can be both primary - with aerogenic infections, and secondary - the complication of the other forms listed above.

Diagnosis of plague

1. Analysis of clinical and epidemiological data: in addition to standard clinical manifestations, investigate the place of residence or location at the moment and whether this place corresponds to a natural focal point.
2. Laboratory criteria:
- UAC: ↑ Lc and Nf with the formula shifted to the left( ie ↑ P / y, C / I, etc.), ↑ ESR;An increase in neutrophils occurs at the compensatory stage, as soon as the depot is depleted, Nf ↓( neutropenia).
- evaluate the parameters of the KHS: the amount of bicarbonate, buffer bases, OH and oxygen capacity of blood, etc.
- OAM: proteinuria, hematuria, bacteriuria - all this will only indicate the degree of compensatory response and seeding.
- X-ray diagnostics: ↓ mediastenal lymph nodes, focal / lobular / pseudolabular pneumonia, RDS( respiratory distress syndrome).
- Lumbar puncture with meningic symptoms( rigidity of the occipital muscles, positive symptoms of Kering and Brudzinsky), in which they show: 3-digit neutrophilic pleocytosis + ↑ [protein] + ↓ [glu].
- Investigation of the bubo / ulcer / carbuncle puff / sputum / nasopharyngeal swab / blood / urine / bowel movements / cerebrospinal fluid - that is where the symptoms dominate and the biological material is sent to bacteriological and bacteriological studies - an initial result in an hour, andthe final in 12 hours( with the appearance of plague stalactites - this makes the diagnosis indisputable).
- RPHA( passive hemagglutination reaction), RIF, ELISA, RNGA

Plague causative agent( electron microscopy)

When suspected of plague, laboratory tests are carried out in anti-plague suits, in specialized laboratory conditions, using special dishes and bixes, and also with mandatoryavailability of disinfectants.

Treatment of plague

Treatment is combined with bed rest and gentle nutrition( table A).

1. Etiotropic treatment( directed against the pathogen) - this stage should start only with one suspicion of plague, without waiting for bacteriological confirmation. In a certain form, different combinations of drugs are used, alternating with each other, the most successful combinations in this case:
- Cyflriaxone or Ciprofloxacin + streptomycin, or gentamicin, or rifampicin
- Rifampicin + Streptomycin

2. Pathogenetic treatment: fighting acidosis, cardiovascularand respiratory insufficiency, ITH and DIC-syndrome. In this treatment, colloidal solutions( rheopolyglucin, plasma) and crystalloid( 10% glucose)
3 are administered. Symptomatic therapy as these or other dominant symptoms manifest themselves.

Complications of plague

Development of irreversible stages of ITH and ICE, decompensation of organs and systems, secondary bacterial complications, lethal outcome.

Prevention of plague

Nonspecific: epidemiological surveillance of natural foci;reduction of rodent numbers with disinsection;constant monitoring of the population in the risk zone;preparation of medical institutions and medical personnel for work with plague patients;prevention of delivery from other countries.
Specific: annual immunization with live anti-plague vaccine of people living in or at risk areas;People who come into contact with the sick plague, their belongings, the corpses of animals, carry out emergency antibiotic prophylaxis with the same drugs as for treatment.
It is believed that post-infectional immunity is strong and lifelong, but cases of repeated infection have been reported.

* National leadership of infectious diseases, refer to the plague of zoonoses, ie to those that can not spread from person to person. But can this be considered legitimate, remembering the epidemic history of Europe in the 14th century, when in 1346-1351, from the 100 million people there were only 70 million - I do not think that this characteristic is suitable, since only those diseases that are transferred from animals are called "zoonosis"to animals and the person is an "infectious dead end", ie without the possibility of infecting other people, and "zooantraponosis" means infection not only between animals, but also between people.

Therapist doctor Shabanova I.Е.