CHOLERA

CHOLERA is an acute infectious disease characterized by diarrhea, vomiting, and severe dehydration of the body.

Pathogens - cholera vibrios: classical cholera vibrio and vibrio El Tor. Cholera vibrios are mobile, slightly curved in the form of a comma; Spores and capsules do not form. Cholera causative agents are obligate aerobes. When they are cultivated on peptone water, surface growth is observed in the form of a bluish-gray soft film that is easily destroyed by shaking. Cholera vibrios have H- and O-antigens.

From patients with acute gastrointestinal diseases, as well as from wastewater and open water bodies, so-called NAG-vibrios are sometimes isolated, not agglutinated with typical anti-cholera sera. Given the complexity of differentiation of cholerae and NAG-vibrios, these pathogens are given the same anti-epidemic measures as in cholera. Cholera causative agents are stable in the environment. In water, they survive from several days to several weeks, in feces without drying - 217 days, but very sensitive to sunlight, drying, disinfectants, especially to acids, quickly die by boiling. Vibrio El Tor compared with the classical is more stable in the external environment. The prolonged survival of cholera vibrios is facilitated by the contamination of open water bodies. In them, the vibrio can develop, accumulating in the inhabitants of water bodies (fish, crabs, mollusks, etc.).

Sources of infection are patients with cholera, convalescents and vibrio-carriers and healthy (transient) carriers. Patients with a pronounced clinical picture of cholera discharge into the external environment per day up to 10 - 30 liters of stool, in 1 ml of which contains from 106 to 109 vibrios. Reconvalvesent-vibrio-carriers isolate pathogens on average within 2-4 weeks, transient carriers - 9-14 days. The intensity of vibrio selection is lower in them - from 102 to 109 vibrios in 1 g of feces. The leading way to transmit cholera is water. Infection occurs when drinking infected water, using it to wash vegetables, fruits, while bathing. Food outbreaks of cholera usually occur among a limited number of people who consume infected foods (milk, fish, shrimp, crabs, mollusks). With the contact-home path the causative agent can be brought into the mouth by hand or through objects infected with secretions of patients. Spread of cholera can contribute to flies. Susceptibility to cholera is high. The transferred disease leaves after itself relatively stable immunity. Repeated cases of the disease are rare. Artificial immunity to cholera is defective, as the effectiveness of existing vaccines is still low.

Clinical picture . The incubation period ranges from a few hours to 5 days (an average of 2-3 days). The disease can occur in typical and atypical forms. There are mild, moderate and severe forms of the disease, which depend on the degree of dehydration and developing hemodynamic and metabolic disorders. Diarrhea is the initial, characteristic symptom of cholera, occurs acutely, often suddenly at night or in the morning. Patients feel imperative desires for defecation without tenesmus and abdominal pain. The stool is plentiful, stools first have a fecal character with particles of undigested food, then become liquid, watery, with floating flakes. In the future they can take the form of a rice broth with the smell of fish or raw grated potatoes. The patient's appetite decreases, thirst and muscle weakness develop. Body temperature usually remains normal, in severe cases - decreased.

On examination, the pulse becomes more frequent, the tongue becomes dry. The stomach is drawn in, painless. The disease can quickly end in recovery or progress. In the latter case, the chair becomes more frequent (more than 10 times a day), a multiple vomiting joins the fountain without nausea and pain in the epigastrium. Vomit initially contain the remains of food, then become watery, yellow in color. Profuse diarrhea and multiple profuse vomiting quickly (within a few hours) lead to severe dehydration. Muscular weakness, thirst, dry mouth grows. Due to the violation of the water-salt balance and accumulation of lactic acid, short-term cramps of the calf muscles, feet and hands appear in some patients, diuresis decreases. The skin is dry, its turgor is lowered, unstable cyanosis is noted. Mucous membranes are also dry. Often observed hoarseness of voice, increased heart rate, lower blood pressure.

Absence of treatment or its insufficiency lead to an increase in dehydration. The facial features are sharpened, cyanosis and dryness of the mucous membranes and skin become worse. The turgor of the skin decreases, on wrists it becomes wrinkled ("the hands of the laundress"). Expressed the muscular relief of the body, aphonia , tonic convulsions of individual muscle groups appear, urination ceases. Body temperature is normal or decreased.

In severe cases of cholera, severe dehydration can develop within 12 hours. Diarrhea and vomiting later become less frequent or completely stop. Often, the tip of the nose, ears, lips, marginal edges of the eyelids become violet or almost black in color. The facial features are even more sharpened, there is a cyanosis around the eyes (a symptom of "dark glasses"), eyeballs sink deeply, turned upward. Consciousness has been preserved for a long time. The voice is soundless, the body temperature drops to 35 - 34 ° C. The skin is cold to the touch, it is easy to gather in folds and for a long time does not straighten ("cholera fold"). Pulse is arrhythmic, weak filling and tension, blood pressure is practically not determined. Dyspnea increases, breathing arrhythmic, superficial (up to 40 - 60 in 1 min). Convulsions of a tonic nature extend to the pectoral muscles, to the diaphragm, which leads to a painful hiccup. The stomach is sunken, soft, painful during muscle spasms. Anuria develops. In the absence of adequate treatment, consciousness is lost, coma and asphyxia occur.

Atypical forms of the disease include lightning and worn out. With the lightning-fast form of cholera, a sudden onset and rapid development of dehydration, convulsions of all muscle groups, meningeal and encephalitic symptoms are observed. The erased form is characterized by scant symptoms and mild course of the disease.

Cholera El Tor is clinically similar to classical cholera, but more often it is easy, atypical, with prolonged vibrio discharge.

Complications of the disease are associated with the development of hypovolemic shock and the attachment of secondary bacterial flora: acute renal failure , pulmonary edema, pneumonia , abscesses , phlegmon of various locations.

Diagnosis is based on a set of anamnestic, epidemiological, clinical and laboratory data. It is necessary to take into account the sequence of development of the symptoms of the disease, the absence of chills and abdominal pain, the nature of stool and vomit (at normal or low temperature). Bacteriological method is the main one in laboratory diagnostics of cholera. The material for the study is the vomiting and stool masses, and in the period of convalescence and in bacterioviruses - duodenal contents. The material for the study must be taken before the appointment of antibiotic therapy and not earlier than 36-48 hours after its termination. Crops of the material are produced on liquid and solid nutrient media not later than 3 hours after taking it.

Cholera often has to differentiate from certain foodborne infections and escherichiosis. In these cases, attention should be paid to the epidemiological history and early bacteriological study of the patient's discharge.

Treatment . The leading value in therapy is compensation for fluid loss, electrolytes and correction of metabolic disorders. In case of dehydration, immediate intravenous (or intra-arterial) rehydration is necessary to compensate for fluid deficiency. To this end, polyionic apyrogenic solutions are used.

Rehydration measures are divided into primary rehydration - replenishment of the already existing water-electrolyte deficiency and compensatory rehydration - replenishment of the continued loss of water and electrolytes. Rehydration therapy should be carried out in specialized departments or wards equipped with appropriate equipment (Phillips beds or "cholera bed", scales, dishes for collecting and measuring the volume of feces, vomit, urine). Primary rehydration in patients with severe forms of dehydration is carried out by intravenous administration of a standard poly-ion solution of trisol, whose composition is close to the salt composition of the feces of the cholera patient: 5 g of sodium chloride, 4 g of sodium hydrogencarbonate and 1 g of potassium chloride are contained in 1 liter of pyrogen- .

In recent years, polyionic solutions "Khlosol", "Acesol", "Lactasol", "Quartasol", "Disol" have been increasingly used. When infusion therapy of patients with a significant degree of dehydration, the amount of liquid introduced in the first 1 to 1.5 h should be about 10% of the body weight of the patient. Before infusion, the solution should be heated to 38 - 40 ° C. The first 2-4 liters of solution are injected (80-120 ml / min) and then drip at a rate of 30-60 ml / min. After the completion of the primary rehydration, they begin to perform compensatory rehydration, the volume and speed of which are determined by the continuing loss of water and salts. To this end, every 2 hours, measure the volume of feces and vomit (separately from urine), determine the hematocrit, the level of sodium and potassium in the serum, pH and make the necessary adjustments to the therapy.

Occurring sometimes vomiting does not serve as a contraindication to the continuation of rehydration. After cessation of vomiting, administer tetracycline at a dose of 0.3-0.5 g 4 times a day for 5 days. Against the background of antibacterial therapy, the duration of diarrhea is shortened and bacteriological sanitation of the ballroom is accelerated. Timely implementation of complex therapy provides at present a reduction in mortality from cholera (1-3% and less).

The discharge of patients from the hospital is usually performed on the 10th-11th day of the disease after a clinical recovery and three negative results of bacteriological examination of feces. Bacteriological examination is conducted no earlier than 24 to 36 hours after the abolition of antibiotics for 3 consecutive days. The first feces removal is performed after the patient is prescribed a salt laxative (20-30 g magnesium sulfate). In convalescents, a bacteriological study of duodenal contents is carried out. For the treatment of vibrio liberators, tetracycline is used at a dose of 0.3 g 4 times a day for 3 to 5 days, and with repeated vibrio release, levomycetin is 0.5 g 4 times a day. A special diet for patients with cholera is not required. Since the first days, diet No. 4 is prescribed, and from 3 to 5 days of treatment, a transition to a common table is possible. After the normalization of the stool, it is recommended to include in the diet foods rich in potassium (dried apricots, bananas, tomato and orange juice).

Prevention. The system of measures for the prevention of cholera is aimed at preventing the importation of this infection into our country from disadvantaged areas, the implementation of epidemiological surveillance and improvement of the sanitary and communal condition of populated areas. For persons arriving from countries where there is a problem with cholera, a medical observation is established for 5 days, during which time a single bacteriological study is performed. With the threat of cholera, obligatory hospitalization and bacteriological examination of all patients with acute intestinal diseases. Immunize against the cholera of the local population.

When isolating the causative agent, cholera from environmental objects include: a temporary ban on the use of water from open water bodies; Temporary increase in the multiplicity (once in 10 days) of bacteriological studies of the water of open water bodies, drinking and technical water pipes, sewage and contents of cesspools; Triple bacteriological examination for cholera of all patients with acute intestinal diseases; Temporary hyperchlorination of drinking and technical water. In the hearth of cholera, a complex of anti-epidemic measures is carried out, the main of which are: urgent isolation, hospitalization, examination and treatment of identified patients with cholera and vibrio-carriers; Active identification of patients by house-to-house detours, provisional hospitalization and examination of all patients with acute gastrointestinal diseases in cholera; Identification of contact persons, isolation of them or only medical supervision for 5 days, bacteriological examination for cholera and preventive treatment with antibiotics (tetracycline - 0.3 g 3 times a day for 4 days); Epidemiological examination in the outbreak; Current and final disinfection; Sanitary-hygienic measures and sanitary-educational work; Epidemiological analysis of the outbreak. For the purpose of specific prophylaxis, cholerogen-atoxin is used. Vaccinations are produced once with a needleless injector in a dose of 0.8 ml of the drug for adults. Revaccination according to epidemiological indications can be carried out not earlier than 3 months after the initial vaccination.