Cholera epidemiology clinic diagnostics treatment and prevention. Cholera - clinic, diagnosis, prevention, treatment of an infectious disease

Anyone who is interested in historical books must have read about cholera epidemics that sometimes mowed down entire cities. Moreover, references to this disease are found all over the world. To date, the disease has not been completely defeated, but cases of the disease in the middle latitudes are quite rare: the largest number of cholera patients occurs in third world countries.

Cholera is an acute bacterial intestinal infection. This disease affects the small intestine, if not properly treated, it quickly leads to severe dehydration, and, as a result, death. Usually the disease is epidemiological in nature.

What causes disease

The causative agent of such a disease as cholera is a group of bacteria, which is also called cholera vibrios. And as with any other infectious disease, the question is very important: how cholera is transmitted. On animals, these bacteria do not take root due to species immunity, so it is impossible to get infected, for example, from a pet. The only exceptions are flies, but only for the reason that these insects often delve into excrement, and feces are one of the main sources of infection. Also, cholera vibrio feels great in an alkaline environment, in water, in products. And, of course, you can get the disease directly - from person to person.

Almost all cholera pathogens can be destroyed by boiling, but there are also certain species that show an extreme degree of resistance - for example, El Tor vibrio.

How the disease manifests itself

After contracting a disease such as cholera, symptoms do not appear immediately. The incubation period usually lasts about a day or two, but in some cases it takes up to 5 days from infection to the first signs of illness. Then the following symptoms make themselves felt:

• Severe diarrhea with characteristic feces (colorless discharge of a liquid or mushy consistency). These signs appear immediately after the incubation period passes. Sometimes a person can go to the toilet more than a dozen times a day. Such symptoms are most characteristic of cholera.
• Nausea accompanied by vomiting. Initially, vomit consists mainly of ingested food. Then it is replaced by the same colorless substance, most of all similar to liquid boiled rice porridge.
• The need to excrete urine is greatly reduced: the patient can urinate at most 1-2 times a day, or even not urinate at all.
• There are signs of dehydration: facial features become angular, sharp, mucous membranes are dry, the patient is constantly thirsty.
• Severe weakness, lethargy. Pulse and blood pressure can be greatly reduced.
• The occurrence of seizures, chewing and calf muscles are usually affected. These symptoms appear a few days after the first manifestations of the disease.

As can be seen from the above, the symptoms of cholera are extremely disturbing and difficult to miss. Cholera is especially severe in children: a critical degree of dehydration occurs much faster than in adults, convulsions, disorders in the nervous system up to coma are more often observed. Therefore, if the symptoms have shown themselves, it is extremely important not to waste a minute, because only timely treatment will give a person the opportunity to return to normal life.

How the disease is diagnosed

The most accurate way to determine if a person has cholera is to take biological material for analysis. Such material can be particles of feces and vomit of the patient. It is also possible to take bile obtained during duodenal sounding for analysis. Sometimes rectal material sampling is practiced: for this, a cotton swab or an aluminum loop is inserted into the rectum for 5–19 cm. The collected materials must be delivered for examination within 2-3 hours, no later. If it is not possible to deliver so quickly, then the samples should be placed in a special nutrient medium.

Sometimes, when cases of cholera are epidemic, a so-called mass study is done: samples are taken from 10 people at once, and if cholera was found in a common test tube, only then individual analyzes are made. This greatly helps to save time and materials.

How to cure cholera

Due to the high degree of contagiousness, cholera is treated only in a hospital setting. For patients, a special isolated block is allocated in the infectious diseases department. Cholera is accompanied by severe weakness, so bed rest is indicated for this disease, and in some cases it is more appropriate to use a special bed that has holes for the buttocks, as well as built-in scales (Philips bed). Massage and physiotherapy treatment does not provide.

As for the diet, for the period of treatment it is necessary to significantly reduce the intake of carbohydrates and fats. Everything that provokes fermentation and decay is also banned. If we talk about specific products, then in the acute period of the disease, the following dishes should be avoided:

• Fatty, rich broths.
• Soups with milk.
• Freshly baked bread and flour products.
• All dairy products.
• Fresh and dried vegetables and fruits.
• Sweet: jam, sugar, honey, sweets, cakes, etc.
• Food with an abundance of hot spices.
• Smoked products.

As for the permitted products, these include:

• Soups on the water with slimy cereals (rice, oatmeal).
• Kashi on the water: oatmeal, grated rice, semolina.
• White bread croutons.
• Steam cutlets or meatballs from lean meat: veal, rabbit meat, chicken fillet.
• Rosehip broth, currant and / or quince compote.
• Low-fat cottage cheese, grated to the state of a soufflé.

As the acute period passes, some relaxations can be made to the diet, but only a specialist should decide this.

After recovery, during the period of final rehabilitation, it is recommended to add potassium-rich foods to the diet: bananas, dried apricots, currants, grapes, boiled potatoes in their skins.

Treatment with medication

At first, treatment consists in overcoming dehydration, i.e., fluid must enter the patient's body faster than it leaves. For this purpose, the patient is given to drink (or injected with a probe into the stomach) a water-salt solution, which consists of water, baking soda, salt, potassium chloride and sugar. In especially severe conditions, a saline solution is administered intravenously.

In order to destroy the pathogen - cholera vibrios, the following antibiotics are used:

• Erythromycin. For adults, the dosage is 5 cubes every 6 hours.
• Tetracycline. It is prescribed in the amount of 0.3-0.5 g in a single dose. It should be administered at intervals of 6 hours.
• Levomycetin.
• Doxycycline.

Of course, antibiotics are not prescribed all at once - one of them is chosen. Moreover, the above dosages - an approximate, exact dose and the number of doses per day should be prescribed by a doctor.

Preventive measures - how to avoid infection

To date, cholera epidemics occur in India, Africa, and some countries in the Middle East. If a trip there is not planned, then general prevention will help here. It consists of the following measures:

1. When swimming in water, care must be taken to ensure that water does not enter the mouth.
2. Water from questionable sources should be boiled before drinking.
3. You should not buy or eat food in establishments if there are doubts about the observance of sanitary standards there.
4. Before eating, hands should be thoroughly washed with hot water, or better, treated with an antiseptic. This is especially true for situations where you need to eat on the street.
5. Hands must be thoroughly cleaned when visiting public restrooms.

If a person plans to travel to those countries where infection with this disease, cholera, is highly likely, then prevention consists in ensuring that all the necessary vaccinations are made before the trip. If contact with the patient has occurred, then the next 5 days you should stay in isolation and take tests to verify the presence or absence of infection. Often in such cases, emergency prophylaxis is prescribed, namely, a course of antibiotics, the same ones that are used to treat cholera.

Although there have been no cholera epidemics in our latitudes for quite a long time, and modern drugs can successfully fight this disease, it should be remembered that cholera is the most dangerous infectious disease, isolated cases of which are found throughout the globe. Therefore, all precautions should be followed, and if any signs appear that indicate the presence of a disease such as cholera, you should immediately seek help from the hospital.

Cholera (cholera) is an acute anthroponotic infectious disease with a fecal-oral mechanism of pathogen transmission, which is characterized by massive diarrhea with rapid development of dehydration. In connection with the possibility of mass distribution, it refers to quarantine diseases dangerous to humans.

ICD codes -10 A00. Cholera.

A00.0. Cholera caused by Vibrio cholerae 01, biovar cholerae.
A00.1. Cholera caused by vibrio cholerae 01, biovar eltor.
A00.9. Cholera, unspecified.

Etiology (causes) of cholera

The causative agent of cholera Vibrio cholerae belongs to the Vibrio genus of the Vibrionaceae family.

Vibrio cholerae is represented by two biovars, similar in morphological and tinctorial properties (the cholera proper biovar and the El Tor biovar).

The causative agents of cholera are short curved Gram-negative rods (1.5–3 µm long and 0.2–0.6 µm wide), highly mobile due to the presence of a polarly located flagellum. They do not form spores and capsules, they are located in parallel, in a smear they resemble a flock of fish, they are cultivated on alkaline nutrient media. Vibrio cholerae El Tor, in contrast to the classical biological variants, are able to hemolyze sheep erythrocytes.

Vibrios contain heat-stable O-antigens (somatic) and heat-labile H-antigens (flagella). The latter are group, and according to O-antigens, cholera vibrios are divided into three serological types: Ogawa (contains the antigenic fraction B), Inaba (contains the fraction C) and the intermediate type Gikoshima (contains both fractions - B and C). In relation to cholera phages, they are divided into five main phage types.

Pathogenic factors:
· mobility;
· chemotaxis, with the help of which the vibrio overcomes the mucous layer and interacts with the epithelial cells of the small intestine;
· adhesion and colonization factors, with the help of which the vibrio adheres to the microvilli and colonizes the mucous membrane of the small intestine;
enzymes (mucinase, protease, neuraminidase, lecithinase) that promote adhesion and colonization, as they destroy the substances that make up the mucus;
cholerogen exotoxin - the main factor that determines the pathogenesis of the disease, namely, it recognizes the enterocyte receptor and binds to it, forms an intramembrane hydrophobic channel for the passage of subunit A, which interacts with nicotinamide adenine dinucleotide, causes hydrolysis of adenosine triphosphate with subsequent formation of cAMP;
factors that increase capillary permeability;
endotoxin - thermostable LPS, which does not play a significant role in the development of clinical manifestations of the disease. Antibodies formed against endotoxin and having a pronounced vibriocidal effect are an important component of post-infection and post-vaccination immunity.

Vibrio cholerae survive well at low temperatures; they remain in ice for up to 1 month, in sea water - up to 47 days, in river water - from 3–5 days to several weeks, in soil - from 8 days to 3 months, in feces - up to 3 days, on raw vegetables - 2 -4 days, on fruits - 1-2 days. Vibrio cholerae at 80 ° C die after 5 minutes, at 100 ° C - instantly; highly sensitive to acids, drying and direct sunlight, under the action of chloramine and other disinfectants they die in 5–15 minutes, they are well and long preserved and even multiply in open reservoirs and wastewater rich in organic substances.

Epidemiology of cholera

Source of the infectious agent- a person (sick and vibrio-carrier).

Patients with erased and mild forms of the disease who remain socially active are especially dangerous.

Mechanism of transmission- fecal-oral. Ways of transmission - water, alimentary, contact-household. The waterway is critical to the rapid epidemic and pandemic spread of cholera. At the same time, not only drinking water, but also using it for household needs (washing vegetables, fruits, etc.), swimming in an infected reservoir, as well as eating fish, crayfish, shrimp, oysters caught there and not undergoing heat treatment, can lead to cholera infection.

Susceptibility to cholera is universal. The most susceptible to the disease are people with reduced acidity of gastric juice (chronic gastritis, pernicious anemia, helminthic infestations, alcoholism).

After the illness, antimicrobial and antitoxic immunity is developed, which lasts from 1 to 3 years.

The epidemic process is characterized by acute explosive outbreaks, group diseases and individual imported cases. Thanks to wide transport links, cholera is systematically brought into the territory of countries free from it. Six pandemics of cholera have been described. Currently, the seventh pandemic, caused by vibrio El Tor, is ongoing.

Classical cholera is common in India, Bangladesh, Pakistan, El Tor cholera - in Indonesia, Thailand and other countries of Southeast Asia. On the territory of Russia, mainly imported cases are recorded. Over the past 20 years, more than 100 cases of importation into seven regions of the country have been noted. The main reason for this is tourism (85%). There have been cases of cholera among foreign citizens.

The most severe was the cholera epidemic in Dagestan in 1994, where 2359 cases were registered. The infection was brought by pilgrims who made the Hajj to Saudi Arabia.

As with all intestinal infections, cholera in countries with a temperate climate is characterized by summer-autumn seasonality.

Measures to prevent cholera

Non-specific prophylaxis

It is aimed at providing the population with good-quality drinking water, disinfecting wastewater, sanitary cleaning and improvement of populated areas, and informing the population. Employees of the epidemiological surveillance system are working to prevent the introduction of the pathogen and its spread on the territory of the country in accordance with the rules of sanitary protection of the territory, as well as a planned study of the water of open reservoirs for the presence of cholera vibrio in the sanitary protection zones of water intakes, places of mass bathing, port waters, etc. d.

Analysis of data on the incidence of cholera, examination and bacteriological examination (according to indications) of citizens who arrived from abroad are being carried out.

According to international epidemiological rules, persons arriving from cholera-prone countries are subject to a five-day observation with a single bacteriological examination.

A comprehensive plan of anti-epidemic measures is being carried out in the outbreak, including hospitalization of sick people and vibrio carriers, isolation of those who contacted and medical observation of them for 5 days with a 3-fold bacteriological examination. Carry out current and final disinfection.

Emergency prevention includes the use of antibacterial drugs (Table 17-9).

Table 17-9. Schemes for the use of antibacterial drugs for emergency prevention of cholera

Note. When isolating vibrio cholerae sensitive to sulfamethoxazole + trimethoprim and furazolidone, pregnant women are prescribed furazolidone, children - sulfamethoxazole + trimethoprim (biseptol).

Specific prophylaxis

For specific prophylaxis, cholera vaccine and cholerogen anatoxin are used. Vaccination is carried out according to epidemic indications. A vaccine containing 8-10 vibrios per 1 ml is injected under the skin, the first time 1 ml, the second time (after 7-10 days) 1.5 ml. Children aged 2-5 years old are administered 0.3 and 0.5 ml, 5-10 years old - 0.5 and 0.7 ml, 10-15 years old - 0.7-1 ml, respectively. Cholerogen-anatoxin is injected once a year strictly under the skin below the angle of the scapula. Revaccination is carried out according to epidemic indications no earlier than 3 months after primary immunization.

Adults need 0.5 ml of the drug (also 0.5 ml for revaccination), children from 7 to 10 years old - 0.1 and 0.2 ml, respectively, 11–14 years old - 0.2 and 0.4 ml, 15– 17 years old - 0.3 and 0.5 ml. The International Certificate of Vaccination against Cholera is valid for 6 months after vaccination or revaccination.

cholera pathogenesis

The entrance gate of infection is the digestive tract. The disease develops only when pathogens overcome the gastric barrier (usually observed in the period of basal secretion, when the pH of the gastric contents is close to 7), reach the small intestine, where they begin to multiply intensively and secrete exotoxin. Enterotoxin or cholerogen determines the occurrence of the main manifestations of cholera. Cholera syndrome is associated with the presence of two substances in this vibrio: protein enterotoxin - cholerogen (exotoxin) and neuraminidase. Cholerogen binds to a specific enterocyte receptor - ganglioside. Under the action of neuraminidase, a specific receptor is formed from gangliosides. The cholerogen-specific receptor complex activates adenylate cyclase, which initiates the synthesis of cAMP.

Adenosine triphosphate regulates by means of an ion pump the secretion of water and electrolytes from the cell into the intestinal lumen. As a result, the mucous membrane of the small intestine begins to secrete a huge amount of isotonic fluid, which does not have time to be absorbed in the large intestine - isotonic diarrhea develops. With 1 liter of feces, the body loses 5 g of sodium chloride, 4 g of sodium bicarbonate, 1 g of potassium chloride. The addition of vomiting increases the amount of fluid lost.

As a result, the volume of plasma decreases, the volume of circulating blood decreases and it thickens. The fluid is redistributed from the interstitial to the intravascular space. There are hemodynamic disorders, microcirculation disorders, resulting in dehydration shock and acute renal failure. Metabolic acidosis develops, which is accompanied by convulsions. Hypokalemia causes arrhythmias, hypotension, myocardial changes, and intestinal atony.

Clinical picture (symptoms) of cholera

Incubation period from several hours to 5 days, more often 2-3 days.

cholera classification

According to the severity of clinical manifestations, blurred, mild, moderate, severe and very severe forms of cholera are distinguished, determined by the degree of dehydration.

IN AND. Pokrovsky distinguishes the following degrees of dehydration:
I degree, when patients lose a volume of fluid equal to 1-3% of body weight (erased and mild forms);
II degree - losses reach 4–6% (moderate form);
III degree - 7–9% (severe);
· IV degree of dehydration with a loss of more than 9% corresponds to a very severe course of cholera.

Currently, I degree of dehydration occurs in 50-60% of patients, II - in 20-25%, III - in 8-10%, IV - in 8-10% (Tables 17-10).

Table 17-10. Assessing the severity of dehydration in adults and children

The main symptoms and dynamics of their development

The disease begins acutely, without fever and prodromal phenomena.

The first clinical signs are a sudden urge to defecate and the passage of mushy or watery stools from the very beginning.

Subsequently, these imperative urges are repeated. The stools lose their fecal character and often have the appearance of rice water: translucent, cloudy white in color, sometimes with gray floating flakes, odorless or with the smell of fresh water. The patient notes rumbling and discomfort in the umbilical region.

In patients with mild form of cholera defecation is repeated no more than 3-5 times a day, the general state of health remains satisfactory, slight sensations of weakness, thirst, dry mouth. The duration of the disease is limited to 1-2 days.

With moderate severity(dehydration II degree) the disease progresses, vomiting joins the diarrhea, increasing in frequency. The vomit has the same rice water appearance as the stool. It is characteristic that vomiting is not accompanied by any tension and nausea. With the addition of vomiting, exsicosis progresses rapidly. Thirst becomes excruciating, the tongue is dry, with a "chalky coating", the skin, mucous membranes of the eyes and oropharynx turn pale, skin turgor decreases. Stool up to 10 times a day, plentiful, does not decrease in volume, but increases. There are single convulsions of the calf muscles, hands, feet, chewing muscles, unstable cyanosis of the lips and fingers, hoarseness of the voice.

Moderate tachycardia, hypotension, oliguria, hypokalemia develop.

The disease in this form lasts 4-5 days.

Severe form of cholera(III degree of dehydration) is characterized by pronounced signs of exsicosis due to abundant (up to 1–1.5 liters per defecation) stool, which becomes so already from the first hours of illness, and the same profuse and repeated vomiting. Patients are concerned about painful cramps in the muscles of the limbs and abdomen, which, as the disease progresses, change from rare clonic to frequent and even give way to tonic convulsions. The voice is weak, thin, often barely audible. The turgor of the skin decreases, the skin gathered in a fold does not straighten out for a long time. The skin of the hands and feet becomes wrinkled ("the washerwoman's hand"). The face takes on the appearance characteristic of cholera: pointed features, sunken eyes, cyanosis of the lips, auricles, earlobes, and nose.

Palpation of the abdomen determines the transfusion of fluid through the intestines, the noise of splashing fluid. Palpation is painless. Tachypnea appears, tachycardia increases to 110–120 per minute. Pulse of weak filling (“thread-like”), heart sounds are muffled, blood pressure progressively falls below 90 mm Hg, first maximum, then minimum and pulse. Body temperature is normal, urination decreases and soon stops. The thickening of the blood is expressed moderately. Indicators of relative plasma density, hematocrit index and blood viscosity at the upper limit of normal or moderately increased. Pronounced hypokalemia of plasma and erythrocytes, hypochloremia, moderate compensatory hypernatremia of plasma and erythrocytes.

A very severe form of cholera(previously called algid) is characterized by a rapid sudden development of the disease, starting with massive continuous bowel movements and profuse vomiting. After 3-12 hours, the patient develops a severe condition of algid, which is characterized by a decrease in body temperature to 34-35.5 ° C, extreme dehydration (patients lose up to 12% of body weight - IV degree dehydration), shortness of breath, anuria, and hemodynamic disturbances by type hypovolemic shock. By the time the patients arrive at the hospital, they develop paresis of the muscles of the stomach and intestines, as a result of which the patients stop vomiting (replaced by convulsive hiccups) and diarrhea (gaping anus, free flow of "intestinal water" from the anus with light pressure on the anterior abdominal wall). Diarrhea and vomiting reappear during or after rehydration. The patients are in a state of prostration. Breathing is frequent, superficial, in some cases Kussmaul breathing is observed.

The color of the skin in such patients acquires an ashy hue (total cyanosis), "dark glasses around the eyes" appear, the eyes are sunken, the sclera is dull, the gaze is unblinking, the voice is absent. The skin is cold and sticky to the touch, easily gathers into a fold and does not straighten out for a long time (sometimes within an hour) ("cholera fold").

Severe forms are more often noted at the beginning and in the midst of an epidemic. At the end of the outbreak and during inter-epidemic times, mild and obliterated forms predominate, indistinguishable from forms of diarrhea of ​​a different etiology. Children under the age of 3 have the most severe cholera: they are less able to tolerate dehydration. In addition, children have a secondary lesion of the central nervous system: adynamia, clonic convulsions, impaired consciousness, up to the development of coma are observed. It is difficult to determine the initial degree of dehydration in children. In such cases, it is impossible to focus on the relative density of the plasma due to the large extracellular fluid volume. Therefore, it is advisable to weigh patients at the time of admission in order to most reliably determine their degree of dehydration. The clinical picture of cholera in children has some features: body temperature often rises, apathy, adynamia, a tendency to epileptiform seizures due to the rapid development of hypokalemia are more pronounced.

The duration of the disease ranges from 3 to 10 days, its subsequent manifestations depend on the adequacy of replacement treatment with electrolytes.

Complications of cholera

Due to violations of hemostasis and microcirculation in patients of older age groups, myocardial infarction, mesenteric thrombosis, and acute cerebrovascular insufficiency are observed. Phlebitis is possible (with vein catheterization), pneumonia often occurs in severe patients.

Diagnosis of cholera

Clinical diagnostics

Clinical diagnosis in the presence of epidemiological data and a characteristic clinical picture (the onset of the disease with diarrhea followed by the addition of vomiting, the absence of pain and fever, the nature of vomit) is not difficult, however, mild, erased forms of the disease, especially isolated cases, are often seen. In these situations, laboratory diagnosis is crucial.

Specific and non-specific laboratory diagnostics

The main and decisive method of laboratory diagnosis of cholera is bacteriological examination. Feces and vomit are used as material, feces are examined for vibrio-carrying; in persons who died from cholera, a ligated segment of the small intestine and gallbladder is taken.

When conducting a bacteriological study, it is necessary to observe three conditions: as soon as possible, sow the material from the patient (cholera vibrio remains in the feces for a short time); · the dishes in which the material is taken should not be disinfected with chemicals and should not contain traces of them, since Vibrio cholerae is very sensitive to them; Eliminate the possibility of contamination and infection of others.

The material must be delivered to the laboratory within the first 3 hours; if this is not possible, preservative media are used (alkaline peptone water, etc.).

The material is collected in individual vessels washed from disinfectant solutions, on the bottom of which a smaller vessel, disinfected by boiling, or sheets of parchment paper are placed. During shipment, the material is placed in a metal container and transported in a special vehicle with an attendant.

Each sample is provided with a label, which indicates the name and surname of the patient, the name of the sample, the place and time of taking, the alleged diagnosis and the name of the person who took the material. In the laboratory, the material is inoculated on liquid and solid nutrient media to isolate and identify a pure culture.

The results of express analysis are obtained after 2-6 hours (indicative response), accelerated analysis - after 8-22 hours (preliminary response), complete analysis - after 36 hours (final response).

Serological methods are of secondary importance and can be used mainly for retrospective diagnosis. For this purpose, microagglutination in phase contrast, RNHA can be used, but it is better to determine the titer of vibriocidal antibodies or antitoxins (antibodies to cholerogen are determined by ELISA or immunofluorescent method).

Differential Diagnosis

Differential diagnosis is carried out with other infections that cause diarrhea. Differential signs are given in table. 17-11.

Table 17-11. Differential diagnosis of cholera

Diagnosis example

A 00.1. Cholera (coproculture of Vibrio eltor), severe course, III degree dehydration.

Indications for hospitalization

All patients with cholera or with suspicion of it are subject to mandatory hospitalization.

cholera treatment

Mode. diet for cholera

A special diet for cholera patients is not required.

Medical therapy

Basic principles of therapy: compensation for fluid loss and restoration of the electrolyte composition of the body; influence on the pathogen.

Treatment must begin in the first hours from the onset of the disease.

Pathogenic agents

Therapy includes primary rehydration (replacement of water and salt losses prior to treatment) and corrective compensatory rehydration (correction of ongoing water and electrolyte losses). Rehydration is considered as a resuscitation event. In the emergency room, during the first 5 minutes, the patient must measure the pulse rate, blood pressure, body weight, take blood to determine the hematocrit or relative density of the blood plasma, electrolyte content, acid-base state, coagulogram, and then start the jet injection of saline solutions.

The volume of solutions administered to adults is calculated using the following formulas.

Cohen formula: V \u003d 4 (or 5) × P × (Ht 6 - Htn), where V is the determined fluid deficit (ml); P - body weight of the patient (kg); Ht 6 - patient's hematocrit; Htn - hematocrit is normal; 4 - coefficient for a hematocrit difference of up to 15, and 5 - for a difference of more than 15.

Phillips formula: V = 4(8) × 1000 × P × (X – 1.024), where V is the determined fluid deficit (ml); P - body weight of the patient (kg); X is the relative density of the patient's plasma; 4 - coefficient at the density of the patient's plasma up to 1.040, and 8 - at a density above 1.041.

In practice, the degree of dehydration and, accordingly, the percentage of body weight loss is usually determined by the criteria presented above. The resulting figure is multiplied by body weight and the volume of fluid loss is obtained. For example, body weight 70 kg, dehydration III degree (8%). Therefore, the loss volume is 70,000 g 0.08 = 5600 g (ml).

Polyionic solutions, preheated to 38–40 °C, are administered intravenously at a rate of 80–120 ml/min at II–IV degrees of dehydration. Various polyionic solutions are used for treatment. The most physiological are Trisol® (5 g of sodium chloride, 4 g of sodium bicarbonate and 1 g of potassium chloride); acesol® (5 g sodium chloride, 2 g sodium acetate, 1 g potassium chloride per 1 liter of pyrogen-free water); chlosol® (4.75 g sodium chloride, 3.6 g sodium acetate and 1.5 g potassium chloride per 1 liter of pyrogen-free water) and lactasol® solution (6.1 g sodium chloride, 3.4 g sodium lactate, 0, 3 g of sodium bicarbonate, 0.3 g of potassium chloride, 0.16 g of calcium chloride and 0.1 g of magnesium chloride per 1 liter of pyrogen-free water).

Jet primary rehydration is carried out using catheterization of central or peripheral veins. After replenishment of losses, increase in blood pressure to the physiological norm, restoration of diuresis, cessation of seizures, the infusion rate is reduced to the required level in order to compensate for ongoing losses. The introduction of solutions is decisive in the treatment of seriously ill patients. As a rule, 15–25 minutes after the start of administration, pulse and blood pressure begin to be determined, and after 30–45 minutes shortness of breath disappears, cyanosis decreases, lips become warmer, and a voice appears. After 4-6 hours, the patient's condition improves significantly, he begins to drink on his own. Every 2 hours, it is necessary to monitor the patient's hematocrit (or relative density of blood plasma), as well as the content of blood electrolytes to correct infusion therapy.

It is a mistake to inject large amounts of 5% glucose solution: not only does this not eliminate the electrolyte deficiency, but, on the contrary, reduces their concentration in plasma. Also transfusion of blood and blood substitutes is not shown. It is unacceptable to use colloidal solutions for rehydration therapy, as they contribute to the development of intracellular dehydration, acute renal failure and shock lung syndrome.

Oral rehydration is needed for cholera patients who do not vomit.

The WHO Expert Committee recommends the following composition: 3.5 g sodium chloride, 2.5 g sodium bicarbonate, 1.5 g potassium chloride, 20 g glucose, 1 liter of boiled water (oralite solution). The addition of glucose® promotes the absorption of sodium and water in the intestines. WHO experts have also proposed another rehydration solution, in which bicarbonate is replaced by more stable sodium citrate (Rehydron®).

Glucosolan® has been developed in Russia and is identical to the WHO glucose-saline solution.

Water-salt therapy is stopped after the appearance of fecal stools in the absence of vomiting and the predominance of the amount of urine over the number of stools in the last 6-12 hours.

Etiotropic therapy

Antibiotics are an additional means of therapy, they do not affect the survival of patients, but they reduce the duration of the clinical manifestations of cholera and accelerate the cleansing of the body from the pathogen. Recommended drugs and schemes for their use are presented in Table. 17-12, 17-13. Apply one of the listed drugs.

Table 17-12. Schemes of a five-day course of antibacterial drugs for the treatment of patients with cholera (I-II degree of dehydration, no vomiting) in tablet form

Table 17-13. Schemes of a 5-day course of antibacterial drugs for the treatment of patients with cholera (presence of vomiting, III-IV degree of dehydration), intravenous administration

Clinical examination

Discharge of patients with cholera (vibrion carriers) is made after their recovery, completion of rehydration and etiotropic therapy and receiving three negative results of bacteriological examination.

Those who have undergone cholera or vibrio-carrying after being discharged from hospitals are allowed to work (study), regardless of profession, they are registered in the territorial departments of epidemiological surveillance and QIZ of polyclinics at the place of residence. Dispensary observation is carried out for 3 months.

Those who have had cholera are subject to a bacteriological examination for cholera: in the first month, a bacteriological examination of feces is carried out once every 10 days, then once a month.

If vibrio carriers are detected in convalescents, they are hospitalized for treatment in an infectious disease hospital, after which dispensary monitoring of them is resumed.

Those who have undergone cholera or vibrio-carrying are removed from the dispensary record if cholera vibrios are not isolated during the dispensary observation.

The history of the development of science is characterized by a long struggle of competing hypotheses. The struggle is especially active in a period when there is no generally accepted theory; then the main support of hypothetical ideas is the problem of opinions. And there is no doubt that every hypothesis can be advanced as a result of the research of a group of scientists who are ready to accept and defend it against competing equally hypothetical views. As a result, we have to say that at the stage of its formation, a scientific theory is transformed into a complete form in the process of analytical interaction between scientists and the development of fundamental sciences.

Studying the method of spreading cholera proposed by John Snow during the period of its hypothetical and unproven pathogen, the author of this work considered it necessary to use the reports of Snow himself in order to show the unsurpassed logic of analytical thinking, the ability to formulate goals and objectives, set and conduct an experiment, collect information, construct it and expound.

Such a mode of activity of a scientist and the nature of awareness, of course, determine the content and tone of the events described, but this is by no means an arithmetic analysis, for example, who, when and at what balance of forces defended a particular discovery? Science is objectively developing; develops smoothly, with rare periods of revolutionary outbursts that radically change the life of mankind. We do not know who invented the lever, but this discovery turned the world order upside down. Theory N.L.S. Carnot (Carnot) and the invention of P. White (White) - a new turn in the history of mankind - the era of steam engines. The discoveries of M. Faraday (Faraday) and the theory of J. Maxwell (Maxwell) are again a leap in the history of mankind, thanks to which the era of electricity began, etc.

In the 17th century, people first learned about the existence of a vast world of microorganisms, the history of which is inseparable from the history of optics. That is, with the discovery and improvement of the microscope, bacteria and protozoa were found, which were often determined in the body of those who died from any disease, and doctors and scientists began to see in them the causes of infectious diseases. By the middle of the XIX century. the main infectious diseases became known, the distinctions between them were defined, and these clinical ideas were in the air in various forms. However, the demonstrative role of microbes in the occurrence of diseases was obtained only in the works of L. Pasteur and R. Koch in the 60-70s. XIX century, and then without universal support. Their thesis was that a microbe can only be recognized as the causative agent of a disease if it is always found in sick people and is not found in healthy people and animals. The second part of this provision today has lost its absolute significance. But even before these works, the method of spreading such an infectious disease as cholera was investigated and brilliantly proven by the English physician John Snow (1813-1858).

Of course, scientifically proven microbial theory played a huge role in understanding the disease under study, but until 1800 cholera (Greek cholera, from the Hebrew chaul rah - a bad disease, according to Hippocrates - from rheo, to flow) was not known in Europe, although it existed in Asia from time immemorial. The initial "relationships" of mankind with this disease were determined relatively late - in the 19th century, since it became known that it had existed in India, China, Tibet, Afghanistan since the 18th century. and is found not only there, but also in other countries of the world, acquiring an endemic character and collecting its terrible tribute everywhere. But this was not yet a serious blow to humanity. In the 19th century, as trade and political links between Asia and the West became more widespread and the concentration of people in cities increased dramatically as a result of the Industrial Revolution, major epidemics began to emerge in Europe and America.

Other entry routes for cholera were the usual Muslim pilgrimages to Mecca and the continental trade routes that linked the Far East, the Asian southeast, and Europe. Crowded settlements became an incredible accumulation of all kinds of sewage and turned into continuous cesspools. So, for example, the excrement of the millionth capital of Russia, St. Petersburg, poured into the Neva, from which water pipes immediately drew drinking water to supply the St. Petersburg population. It is not surprising that every new visitor to St. Petersburg fell ill with an intestinal infection.

The same thing happened in England, and in particular in London. In England, cholera epidemics occurred in 1831-1849 and 1853-1854. and have been associated with transmission by infected individuals. Immediately after the appearance of the disease in Europe, an organized fight against it began, consisting in isolation and quarantine. Despite this, the onset of epidemics could not be prevented. True, cholera rarely gave more than 4% mortality. For example, the plague in the 14th century killed 25 million people - a quarter of the population of Europe; in the 17th century in Basel (Switzerland), 22% of the townspeople died from it, in the 18th century in Koenigsberg - 25%.

There is nothing surprising in the infinite number of epidemics, since at that time the causative agents of infectious diseases were not known, that is, the etiology and, of course, pathogenesis were unknown, and thus there was no nosological unit. And, as a result, the basic principles for the prevention of infectious pathology have not been developed. There was no doctrine about the essence of the epidemic process, including the source of the infectious agent, the mechanisms of its transmission and the degree of people's susceptibility to a particular infection. More globally, it should be understood that in those days there was still no science that would illuminate all aspects of the problem and pave the way for practice. And without these conditions, there can be no corresponding medical specialty.

The question of how cholera spread was especially difficult, that is, unresolved. On the one hand, there was a lot of evidence that cholera was transmitted through direct personal contact. At the same time, there have been many observations in which persons who came into personal contact with the patient, such as doctors, did not fall ill, and outbreaks of epidemics occurred in places far from each other at a great distance.

Some experts saw the cause of the spread of cholera in the water supply. John Snow accepted this hypothesis, refined it by examining the excretions of cholera victims, and also took as a basis another ideology of that time, that is, “morbid matter” as the cause of infectious diseases.

In fact, Snow proved that the Asian visitor (cholera) is able to take on an epidemic form only in those cases when it encounters a favorable environment for itself, which consists in soil and drinking water contamination with human feces with "disease

creative matter." This led to the conclusion that the fight against cholera should consist in eliminating the possibility of such pollution. For this, a sanitary reform was carried out, which consisted in the installation of water closets, a floating sewerage system, irrigation fields and drinking water filtration. Indeed, since the introduction of these measures, England, and then the rest of the countries, got rid of cholera epidemics. And only many years later, R. Koch discovered the cholera vibrio, the properties of which once again confirmed the correctness of the conclusion of J. Snow.

But initially it was not easy to believe in Koch's hypothesis, just as it is not easy to agree with the arguments of opponents. It is not easy to understand scientists and practitioners who are able to unjustifiably stun their ideological opponents. So, for example, an icy attitude to the well-known experiments of R. Koch Rudolf Virchow. Or the equally icy attitude towards Koch of the Munich professor Max von Pettenkofer, who, like R. Virchow, did not believe in the germ theory. In his sensational work On the Mode of the Spread of Cholera, von Pettenkofer defended the old Hippocratic theory of miasms, slightly modernizing it in the sense that, in his opinion, the source of infection should be sought in the structure of the soils of those areas in which the disease is rampant.

It should, however, be noted that in modern times it is easy to look down on the theories of "miasms and emanation" and put them in quotation marks and see them as prejudice. But the theory of microorganisms at that time was too speculative and did not have scientifically proven facts in its essence. And the idea that disease could be spread by foul smells or other noxious fumes (“miasma”) was more progressive than the views that attributed disease to witchcraft or transgression. Moreover, the theory of emanation gave rise to justified anxiety about the overcrowding and unsanitary living and working conditions of the poor. This illustrates the truism of scientific research: an incorrect theory is better than no theory, or, in the words of the English logician Augustus de Morgan, "incorrect hypotheses, properly investigated, yielded more useful results than disordered observation."

So, understanding what we expect from science and practice is not always adequate. That is, it is extremely difficult to understand all scientific and practical hypotheses. Even capable scientists are not always able to accommodate new concepts, generalize old and new experience. In short, Max von Pettenkofer remained committed to the theory of miasms and denied the idea advocated by Koch that "a possible microbe is transmitted from one person to another as a result of infection, direct or through drinking water." Von Pettenkofer believed that the unknown pathogen develops in certain soils favorable for it, such as, for example, in the swampy floodplain of the Ganges or European swamps, etc. A person falls ill by inhaling the fumes emitted by these decaying soils in which "miasmas" have developed. Moreover, Pettenkofer was a man and a researcher whose “conscious” idea won, sometimes blindly, over other logic and worldview, and, like Koch, he was ready to do anything to see her triumph. He was also a very interesting person who lived a romantic, adventurous life. A characteristic trait of Pettenkofer was his contempt for danger. And in order to prove the validity of his statements, Pettenkofer, who was already 75 years old, decided on a “heroic” act: in front of a large audience, consisting of students and Berlin professors, he drank a live culture of cholera vibrios from a test tube, containing millions of lethal doses. As it was then interpreted, “by some unknown chance” nothing happened to Pettenkofer, even the temperature did not rise even by one or two degrees. As they say, a similar incident occurred with I.I. Mechnikov, who also drank a live culture of Vibrio cholerae and suffered minor dyspepsia after that. Today, however, it is known that Vibrio cholerae is an alkali-loving microorganism, and the scientists mentioned suffered from chronic gastritis with high acidity, and this condition prevented infection with cholera. Naturally, Pettenkofer triumphed, nevertheless, the professor's theatrical prank could not save the theory of "pathological inhalations" from discrediting, since a single fact, in the end, cannot refute the truth.

Today, almost two centuries after the victory of the bacteriological theory of diseases, we know that the individual characteristics of an organism fluctuate within very wide limits. Some people may experience a mild or clinically unrecognized disease and subsequently develop immunity. Epidemics in which everyone gets sick are very rare.

Why can some people get sick and yet they don't get sick? This issue has been seen as the main objection to Snow's theory. That is, the opinion expressed against the spread of cholera through water is that anyone who drinks such water should immediately fall ill. This objection stemmed from a misunderstanding as to what field of knowledge the spread of cholera belongs to. The modes of spread of cholera were seen only as a chemical problem, and not a problem of epidemiology (which did not exist at that time), to which it undoubtedly belongs.

Today, such a question, why a person who drank, for example, a decoction with cholera secretions by mistake, did not become infected, is unacceptable. It is hard to believe that he was acceptable even at that time, especially for those who doubted the truth of Snow's theory. And Snow's theory was based on the following hypothesis: “The situations that are explained by the absorption of a minimum amount of secretions from cholera patients are too diverse to explain the spread of the disease; their analysis reveals that cholera spreads fastest where there are the most suitable conditions for its transmission. Hyperacid gastritis, as we understand it, does not apply to such conditions of distribution. Snow also noted that “people belonging to different classes of society perform different functions in the presence of patients, live in different types of houses, have different habits and lifestyles. As a result, they have a different probability of contracting cholera.”

Different probability of infection was due to working conditions. According to Snow's observations, it was, for example, a workhouse. This institution had its own water supply. 5 out of 535 inhabitants died of cholera, while in the surrounding area, about 100 people should have died for this number of people. Or the brewery, which was located near the infamous Broad Street pump - the main source of cholera. None of the employees of the brewery was included in the list of deceased. During a conversation with the owner, it turned out that 70 workers work at the brewery and none of them suffered from cholera. They were all allowed to drink some beer. Therefore, the owner confidently believes, they do not drink water at all. Moreover, they never took water from the pump on Broad Street, since the brewery has its own deep well, in addition to water from the New River ... "

And further, Snow notes, "... that nothing contributes more to the spread of cholera than a lack of personal cleanliness, whether it is associated with habits or lack of water, although this circumstance has not been explained until recently." Moreover, there is no doubt that cholera can enter homes with different standards of living and that “… in the homes of persons with a higher standard of living, it is rarely transmitted from one family member to another. This is due to the constant use of a basin for washing hands and towels, as well as the fact that the premises for cooking and eating are separated from the patient's room. In this connection, doctors do not become infected with cholera, but those who dress the body are infected. Thus, “examination of the corpses of cholera patients is unlikely to ever lead to infection, since the performance of this duty is associated with the subsequent washing of hands and the habits of physicians do not include eating in such situations. On the other hand, ceremonies over the dead body, such as dressing, when performed by working women, are accompanied by eating and drinking and often lead to infection with cholera, while people who come to the funeral and do not come into contact with the corpse often subsequently become infected, obviously by taking food prepared or served by those who touched the cholera patient or his linen and bed ... "

And now it is important to pay attention to the conclusions based on these arguments and given by J. Snow against the “emanation” hypothesis: 1) not everyone who came into personal contact with the patient becomes infected, despite the fact that anyone who comes into contact with the patient or the corpse inhales the “emanation” ", exhaled by them (as those who believed in the contagiousness of "emanation" usually believed); 2) sometimes cholera breaks out during an epidemic in new areas, remote from other cases of diseases, where it was not possible to undergo "emanation".

The logic of the second conclusion was based by the researcher as follows: “If cholera had no other channels of transmission, it would be limited mainly to the crowded dwellings of the poor and those areas into which it accidentally penetrated without being able to overtake new victims, but often it is more widely spreads and penetrates into the wealthy sections of society; I explain this by the fact that cholera excretions are mixed with water used in cooking or drinking, either by seeping through the earth and falling into wells, or through sewer pipes into rivers, which sometimes supply entire cities with water ... "

Another argument against the "emanation" theory put forward by Snow was the following: cholera begins without any obvious symptoms of a general lesion of the body, but only with symptoms of a "stomach" disease; if it had been the result of the inhalation of a poison, symptoms of a general disease would have to show up.

Since we now know that Snow's theory of the water supply as the main transmitter of cholera is correct, we understand that all other routes of transmission can be ignored (sea and other food products contaminated with the excrement of patients or carriers of infection - flies).

However, at that time the transmission routes were not understood, and of course the purpose of Snow's experiment was to find out. Therefore, we can say that Snow's genius was that he noticed and proved the importance of the fact that two different companies supplied water to the same area of ​​London. Both water companies took water from the Thames in places that could be contaminated from the city sewer. But in 1892, after a cholera epidemic during which Snow emphasized many experiences, one of these companies, the Lambeth Company, moved its water treatment system upstream to where the London sewer was not. The other, the Southwark and Vauxhall Company, left things as they were. Both companies supplied drinking water to the same area of ​​the city: “The water supply pipes of each of the companies run along all streets, almost in all yards and alleys. Some houses are serviced by one company and others by another according to the decision of the owner or occupant, with the water companies actively competing with each other. In many cases, a separate house uses a water supply that is not used by neighboring houses. Both companies supply water to the haves and not-haves, both large houses and small buildings; between people who receive water from sources of different companies, there is no difference either in position or in profession. Snow further summarizes the main idea of ​​his experiment: “Since there is no difference at all between the homes and people receiving water from these two companies, or in whatever physical conditions of their environment, it is obvious that no specially designed experiment could have been more carefully test the effect of water supply on the development of cholera than that which is set by the circumstances themselves. The data of the experiment turned out to be grandiose. No less than 300,000 people of both sexes, of all ages and professions, of all levels and social status - from the nobility to the poorest strata, were divided into two groups without their knowledge and will. One group received water tainted with London sewers and everything that might have entered it from cholera patients, while the other group received water completely free from such contamination. It was only necessary to find out the source of water supply for each individual house in which a fatal outbreak of cholera could occur. This task required bringing together two types of information: cholera cases and the source of the water supply. “I wanted to do the research myself in order to have the most satisfactory proof of the truth or falsity of the theory that I have defended for 5 years. I had no reason to doubt the correctness of the conclusions drawn by me on the basis of the large number of facts that I already had. But I thought that the fact that the poison of cholera penetrated the sewers into a large river and spread for many miles through water pipes while maintaining its effect was of such a striking nature and of such importance to society that no degree of accuracy in research and the reliability of its justification could not be excessive."

Snow began to collect information on mortality from cholera in this area of ​​London. Already the first results confirmed his hypothesis about the water source of the spread of cholera: of the 44 deaths in the area, 38 occurred in houses supplied with water by the Southwark and Vauxhall Company.

Finding out which water company serves a particular house has not been easy in all cases. Fortunately, Snow invented a method of chemical testing based on the fact that when silver nitrate is added to water containing chlorides, a white cloud of insoluble silver chloride is formed. He found that the water from these companies differed greatly in chloride content, which was easy to determine. Moreover, the appearance of the water indicated its source quite well, especially when viewed as it flows from a faucet. Even the hours of its arrival on every street testified to its source.

However, water characteristics or company receipts could not replace the statistics of deaths. Snow expressed the death rate as the number of cases per 10,000 households. The following figures were obtained (Table 1).

Thus, the mortality rate in the homes operated by the Southwark and Vauxhall Company was nine times higher than in the homes operated by the Lambeth Company. Moreover, subsequent cholera epidemics clearly confirmed the importance of the drinking source. For example, during the sixth major offensive of cholera that raged in Germany in 1892-1893, the cities of Altona and Vandesbeek, neighboring Hamburg, did not suffer from the disease, while in Hamburg it raged with might and main. This is explained by the fact that these cities constantly received water filtered through a thick layer of sand, while unfiltered water entered Hamburg. And as R. Koch showed, one of the quarters of Hamburg (Hamburger Platz), supplied with filtered water from Altona, also avoided cholera.

Was no exception in terms of the water distribution of cholera and Odessa in 1908, when this disease suddenly appeared there. Odessa at that time already had an exemplary water supply system, a floating system and irrigation fields. But one of the districts of the city - Peresyp - has not yet been sewered. It has always been distinguished by high mortality from typhoid fever, and it was in it that cases of cholera began. The sick, however, were scattered around the city, but an analysis of their place of residence showed that they all live in one small group of houses on Peresyp. A study of the area showed that all the houses of the sick are located near the ditch, into which the sewage of one of the suspicious houses is poured. Vibrio cholerae were found in the contents of this ditch and an epidemiological diagnosis was made. Arrived (probably from Rostov, where there was cholera), the carrier of vibrios infected them with a ditch, from where they were carried by flies to neighboring houses. The ditch was immediately covered with bleach, and cholera diseases immediately and completely stopped. So in all cases, the correct epidemiological diagnosis is of paramount importance in the fight against the epidemic.

But at the time, most experts did not accept Snow's hypothesis and argued against it that not all of those known to have drunk the contaminated water became ill. However, these experts could not formulate a much stronger counterargument. And they needed to find the parameter that would distinguish the diseased from the non-sick and thus justify their hypothesis. But alas! At the same time, Snow analyzes his arguments as follows: “All the facts that prove the spread of cholera by water confirm what I started with, namely, its spread in the crowded dwellings of the poor, in coal mining and other areas through hands contaminated with the secretions of sick people. , and through small doses of these secretions that enter food, just as paint enters the stomach of unscrupulous painters, who, due to the penetration of lead, experience stomach colic. And now it should be noted with more certainty that the larger the angle of view reveals the problem under study to us, the more definitely it seems that this kind of search for understanding, the identification of internal patterns in a complex and obscure aspect of reality is the main goal of science.

So, Snow's genius consisted not only in elucidating the role of the source in the spread of the disease, or in the thoroughness of observations and the correctness of the conclusions, consisting in a correct understanding of the mechanisms of the spread of cholera, but also in the fact that he gave a convincing and beautiful experimental proof of its correctness. For him, a single fact could not disprove the truth. The life path of his theory was destined ... After all, it was Snow who noticed and proved the importance of the event that, by coincidence, in the area of ​​London where the outbreak occurred, some houses received drinking water from one source, and others from another.

Moreover, Snow etiologically and pathogenetically correctly suggested that: “Diseases that are transmitted from one person to another are caused by some substance that passes from the sick to the healthy and which has the ability to increase and multiply in the organs of the person who has been infected.”

And “... since cholera begins with a lesion of the digestive tract and since we have seen that in the early stages of this disease the blood is not affected by any poison, therefore, the “morbid matter” that generates cholera must be introduced into the digestive tract - must, in fact, be accidentally swallowed, since people will not intentionally absorb it, and an increase in disease-causing matter, or cholera poison (enterotoxin, author's note) must occur inside the stomach and intestines.

Analyzing the scientific search of J. Snow, you are once again convinced that reality constantly introduces new facts that science must assimilate into the existing system, and if the facts do not fit into it, you need to revise the system, not the facts.

This kind of research methodology could not save Snow from testing alternative hypotheses explaining one or another system of views on the spread of cholera - emanation, altitude, hard and soft water, limestone and sandstone, drinking habits, seasonal differences in the development of cholera. He showed that these theoretical systems did not explain the results of experimental observations as well as his theory. At the same time, there were separate facts that were better explained by other theories. This struggle of opinions is, of course, objective, since even the most perfect scientific theories, especially when they are new, are in the same contradictory influence and position, and the scientist who put forward them must have civic courage, insight and common sense, so that sometimes do not consider inconsistent facts. Obviously, this is associated with a certain risk, but without it, it is impossible to move forward. That is, the number of assumptions in the creation of new models is so large that the final information product often conflicts with the available facts. And Jon Snow brilliantly overcame this disorder of nature.

John Snow was born in 1813 in the family of a farmer in the city of York (England). At the age of fourteen, he was apprenticed to a surgeon in Newcastle. At the age of 18, John is sent to care for the victims of a major outbreak of cholera that was taking place in the vicinity of the city. In 1838, John Snow takes his exams in London and becomes a member of the Royal Society of Surgeons. But his plans went much further, and he makes a significant contribution to medical research, participating in the development of an air pump for artificial respiration in newborns who could not breathe on their own. They also describe that J. Snow invented an instrument for chest operations. However, it is known for certain that he made a significant contribution to new methods of anesthesia, becoming London's leading specialist in the use of ether. Subsequently, he switched to the use of chloroform as a drug that was easier to use. This transition was due to a number of experimental studies that convinced him of the practicality of chloroform. He used this substance at the birth of the children of Queen Victoria, Prince Leopold and Princess Beatrice. The greatest of his achievements was the study of cholera, which he described in the monograph On the Method of the Spread of Cholera (1854). This work turned out to be a classic example of the application of scientific methods, as well as an excellent story for describing discoveries. John Snow died quite young, in 1858, without finishing work on the book On Chloroform and Other Painkillers.

Before revealing the symptoms of the disease and the impact on the body, we will give a definition of the disease. Cholera is a viral infectious disease caused by the bacterium Vibrio cholerae. The main site of injury is the small intestine. The patient has loose stools, vomiting, intoxication. When sick, a person loses up to 40 liters of fluid per day, causing dehydration, the risk of death. Every year, the disease affects more than 5 million people - 3-5% die. Refers to infections that pose a particular danger to human life. Cholera is characterized by dyspeptic syndromes, in which dehydration of the body is pronounced.

The cholera disease has been known since antiquity, it came to Europe in the 19th century. The peak of the pandemic in Russia occurred in the second half of the 19th century, coinciding with the Crimean War - the death rate was in six figures. In 1854, more than 500 people contracted cholera in central London. J. Snow's report on the impact of the water supply system on the spread of cholera gave impetus to the improvement of sewerage.

The cholera bacterium was discovered by F. Pacini in 1853 and E. Nedzvetsky in 1872.

Cholera has spread to all corners of the globe. The main foci of infection are the countries of Africa and Latin America. Infectious spread is associated with unsanitary conditions in which a person lives. The causative agents are microbes contained on objects and unprocessed foods.

The history of the disease began its journey from antiquity, taking the lives of tens of millions of people. Treatment must be taken seriously. Infectious diseases have claimed more lives than wars!

Properties of cholera vibrio

By producing poison, microbes damage the intestinal mucosa. Under the influence of the poison, the water-salt balance is disturbed, dehydration of the human body occurs.

Properties of toxins:

• Destruction of the epithelium of the small intestine.
• They irritate the digestive tube, causing vomiting, liquid stools.
• Violate the water-salt balance.

The bacterium develops at 16-40C. The optimal variant of the existence of cholera vibrio is 36-37C. Temperatures below zero are not terrible.

The causative agent of the disease is not susceptible to alkali, bacteria live on food, surfaces and soil for up to a month, in water - a couple of months.

Pathogenesis during cholera:

Contaminated food, liquid → penetration into the small intestine → suction of the bacteria to the intestinal wall → increase in the population of the microbe on the intestinal mucosa → release of CTX toxins, the poison disorients the normal functioning of the small intestine → due to toxins, the water-salt balance is disturbed, water and salt particles are disturbed leave the intestines → cells become dehydrated and die, bacteria leave the body along with dead cells.

The etiology of the disease: the source of the disease is a bacterium represented by the biotype of the disease and El Tor. The Bengal cholera clinic has the ability to secrete an exotoxin similar to the cholera bacterium biotype.

Causes of cholera

Causes of the disease:

• Infected person.
• Bacteria carrier. From the outside, it doesn't look charged.

Stools and vomiting of the patient are odorless. Infected substances are not noticed, which leads to the spread of an infectious disease.

The mechanism of transmission of bacteria is fecal-oral, vibrios leave the body through feces, with vomiting. The disease is not transmitted by airborne droplets.

The main ways of infection with cholera:

• Via water: Contaminated water has a high content of bacteria. When swimming, there is a huge risk of infection. Wash dishes, food in such water is not recommended.
• Contact-household: household items, door handles, dishes, linen and other items that the patient has come into contact with are full of pathogens.
• Food: dairy and fish products, fruits and vegetables that have not undergone heat treatment. gets on products through water, the carrier, flies.

Symptoms of the disease

Signs of cholera:

• Vomiting from eating food.
• Increase in body temperature.
• Dehydration: dry mouth.
• Stool in cholera: thin, colorless, white-gray.

The incubation period of cholera is a couple of hours, usually 2-3 days.

Infection classification:

• Erased.
• Easy.
• Medium severity.
• Heavy.
• Very heavy.

There are 4 degrees of dehydration:

• The first - dehydration is 1-3% of body weight.
• The second phase - 4-6% of the total weight of the patient (moderate severity).
• Third - the patient loses 7-9% of the total human fluid.
• Fourth - dehydration more than 9%.

The erased form of cholera is characterized by a single loose stool, no dehydration, and no fever. The first signs are a sharp urge to stool, a watery bowel movement. There is no pain syndrome, the number of “trips” to the chair increases, the volume of bowel movements increases. As a result of dehydration, malaise, a desire to drink, and dryness in the oral cavity appear. The period of the disease state is 1-2 days.

With the loss of fluid in the second stage, the infection progresses, diarrhea is combined with frequently repeated vomiting. Feces and vomit are identical in color. There is dryness in the oral cavity, pale eye retina, withering of the skin. The frequency of bowel movements is up to 10 times a day. Severe complications: cramps of the limbs, hoarseness of the voice. The duration of the course of the disease is up to 5 days.

The severe form is characterized by exsicosis due to strong loose stools (up to 1.5 liters of fluid are lost per 1 act of bowel movement). Symptoms: lethargy of the skin, the appearance of tachypnea, an increase in tachycardia, a thready pulse, rapidly falling blood pressure, decreased urination.

Algid type of cholera (heavier in form) - the rapid development of infection, accompanied by a strong vomit, frequent urge to stool. Weakened immunity. Body temperature in a couple of hours reaches 34-35C. The patient loses more than 12% of the fluid in the body. Symptoms of cholera: shortness of breath, anuria, paralysis of the intestinal muscles.

Appearance of the patient:

• sunken eyes;
• loss of voice
• dullness of the sclera;
• retracted belly.

Laboratory diagnostics shows test results: blood density exceeds 1.035; the index of the ratio of the volume of erythrocytes to the total volume of plasma is 0.65-0.7 l / l.

The risk of developing cholera in children under 3 years of age

Children under the age of three are most susceptible to cholera. Dehydration is worse for babies. It is much more difficult for children to determine the level of dehydration based on plasma density. For a clear and correct analysis, the baby should be weighed.

The differential characteristic of symptoms is different from the course in adults. Feature of cholera vibrio in babies:

• Unreasonable increase in temperature.
• Adynamia.
• Pronounced epileptiform seizures.

The duration of the disease is up to 10 days. Timely rehydration, replacement of electrolytes is the main goal of rapid recovery of the body.

Diagnostics

With an epidemiological outbreak, the diagnosis of the disease is not difficult. In areas where cholera has not occurred, bacterial confirmation is necessary.

Methods for diagnosing the disease:

• objective - the severity of the disease is determined by the symptoms;
• bacteriological - sowing of feces, vomit is given. The causative agent of cholera is determined;
• serological - using blood serum, the presence of vibrio antigen is determined;
• relative plasma density - helps to establish the degree of the disease.
• express diagnostics.

It is important to diagnose the disease in time in order to prescribe the correct treatment for cholera and avoid consequences.

Treatment of the disease

Disease control methods include:

1. Fatty broths.
2. Soups on dairy products.
3. Flour products.
4. Dairy products.
5. Fresh and dried fruits and vegetables.
6. Sweet - jam, honey, sugar.
7. Spicy food.
8. Smoked products.

Allowed products:

• Soup on the water with rice, oatmeal.
• Kashi on the water.
• Crackers.
• Steamed cutlets with low-fat meat products: chicken, veal, rabbit meat.
• Compote of currants, quince.
• Skim cheese.

Medication treatment

To fight dehydration, the patient needs to drink, inject a solution of water and salt into the intestines. In a severe form of the disease, the solution is injected into a vein.

Antibiotics are used to kill the bacteria:

• Levomycetin.
• Doxycycline.

It is necessary to consult a doctor who determines the dosage, the number of doses per day.

Folk treatments for cholera

Cholera is not treated with folk remedies! Alternative methods of treatment are not recommended to be used as the main ones - they are used as accompanying main ones.

• Warming - at a low temperature, the patient should put burners on the body, the room temperature should not be less than 35C.
• Periwinkle. Recipe: 1 tsp brew dried herbs in a glass of water. Cool, strain, take 100 ml three times a day. The drink helps with loose stools, disinfects the intestines.
• Red wine, containing tannin, stops the population of cholera bacteria.
• Chamomile, mint tea. Dilute in an equal proportion of herbs. 5 tbsp of the mixed material, dilute in a liter of liquid. Boil. Drink 1.5-2 liters per day in small doses. Has anti-inflammatory properties.

Consequences of the disease

The lack of steps to cure the disease, delay leads to:

• Hypovolemic shock (low blood pressure).
• Impaired kidney function. It is characterized by a decrease in the release of nitrogenous slag, urine density, acidosis.
• Muscle cramps.
• Thrombophlebitis.
• Breathing disorder.
• Acute circulatory disorders in the brain.
• Re-infection with other types of microbes.

Prevention

Persons arriving from cholera-affected countries must be observed for at least 5 days.

Sanpin (Sanitary norms and rules) about cholera include measures to prevent the spread of the disease in the country.

Prevention of cholera:

• A sick person moves to a separate room - an isolation room. After the symptoms disappear, it is released. It is important to carry out 3 diagnostics with a frequency of once a day. The results of the study should show the absence of microbes in the body.
• Those who have been in contact with the infected are collected - they take a blood test three times, prescribe antibiotic treatment.
• The workplace and the room in which the patient was located must be disinfected. It is done within 3 hours after hospitalization.

During disinfection, it is necessary to observe preventive measures that exclude the possibility of infection - carry out the procedure in special clothing, gloves, and a mask.

Vaccination against disease

Specific prophylaxis includes a vaccine given under the skin. Emergency prevention includes the use of drugs that prevent the spread of bacteria.

Cholera vaccination is an important step in preventing the onset of the disease. The effectiveness of drugs injected under the skin has not been fully proven - they are not recommended for use. The cholera vaccine is not a universal protective method. It is in addition to other measures that kill the source of infection and the virus.

Vaccination helps to identify carriers of infection in adults and children, to prevent the spread of the disease. In addition to the vaccine, a buffer solution is taken to protect the drug from the action of stomach acid. 2 doses are given 1 week apart. The Dukoral vaccine protects the body for six months. You can vaccinate children over 2 years old.

Cholera is an intestinal infection caused by various bacteria that can lead to serious damage to the body and death!

The pathogenesis (development mechanism) of cholera is quite complex and well understood. When V. cholerae enter the stomach, most bacteria do not survive in its acidic environment. The few surviving bacteria maintain their viability and retain nutrients as they pass through the stomach by shutting down protein production.

When the surviving bacteria reach the small intestine, they must move through the thick mucus to reach the intestinal wall, where they can live and multiply. Vibrio cholerae produce flagellin, a protein that forms a coiled, flagella-like structure. Like a corkscrew, the spiral fibers rotate and propel bacteria through the mucus of the small intestine.

Once the cholera bacteria reach the intestinal wall, they no longer need flagella to move. Bacteria stop producing the flagellin protein in order to conserve energy and nutrients for the synthesis of a mixture of proteins that they express in response to a change in the chemical composition of their environment. Upon reaching the intestinal wall, the vibrio begins to produce toxic proteins that cause watery diarrhea in an infected person. New generations of V. cholerae will enter the body of the next host through drinking water or food unless appropriate sanitary measures are applied.

Cholera toxin is an oligomeric complex consisting of six protein subunits: one copy of the subunit - part A and five copies of the subunit - part B, connected by a disulfide bond.

The five B subunits form a five-membered ring that binds to GM1 gangliosides (a human protein) on the surface of intestinal epithelial cells. The A1 part of the subunit is the enzyme, while the A2 chain fits into the center of the B subunit of the ring. After binding, the complex penetrates into the intestinal cell, where it leads to the production of an active biochemical regulator of cAMP (adenosine monophosphate cyclic). It is cAMP, in turn, that leads to the secretion of water, Na+, K+, Cl-, HCO3- into the lumen of the small intestine and rapid dehydration.

Chlorine and sodium ions create a salty environment in the small intestine, which through osmosis can pull up to six liters of water a day through the intestinal cells, causing profuse rice-water diarrhea. The patient quickly becomes dehydrated and loses trace elements if appropriate measures are not taken.

Scientists have investigated the mechanisms of action of Vibrio cholerae, with the help of which it reacts to the changing chemical environment of the stomach, mucous layers and intestinal wall. They discovered a complex cascade of regulatory proteins produced by V. cholerae that control their entry into the intestinal wall and activate their virulence genes, which produce toxins that cause diarrhea in an infected person and allow the bacteria to colonize the intestines.