Cholera is an acute infectious disease with a fecal-oral transmission mechanism, the causative agent of which is Vibrio cholerae. The disease is characterized by severe diarrhea with rapid dehydration and loss of electrolytes. Cholera is one of the quarantine (especially dangerous) infections.
Content
Modes of transmission of cholera
Cholera bacillus is not stable in the external environment. But under favorable conditions it can remain alive in water and on food products for 1-2 months. Disinfectants, even in small quantities, quickly kill the pathogen.
Human susceptibility to cholera is very high. Diseases, as a rule, are epidemic in nature. Susceptibility to cholera reaches 100%. Children and the elderly are especially susceptible to the disease.
A sick person excretes cholera vibrios in feces, vomit, and sometimes in urine. You can become infected by eating near a sick person or sharing objects. The pathogen enters the body only through the mouth.
Infection also occurs through consumption of water and food products contaminated with secretions containing vibrios. Such infection is also possible when consuming vegetables that were grown in the garden and watered with untreated sewage or when washing dishes with contaminated water.
Swimming in contaminated water also leads to illness. It must be taken into account that shrimp, shellfish, and fish are also susceptible to infection and cholera bacillus lives in them for a long time.
Outbreaks of cholera caused by drinking contaminated water are widespread and spread very quickly. If the disease is transmitted by carriers, from person to person, then it spreads slowly. Most often, epidemics appear in summer and autumn.
Hidden carriers of cholera are dangerous, people who have already recovered but still secrete cholera vibrios.
How does the disease develop?
Cholera vibrios, entering the body, die in large numbers in the stomach, since the acidic environment is destructive for them. However, with a large amount of water, a small part of them enters the small intestine. Here the environment for their development is favorable and the colony begins to rapidly expand.
The causative agent of the disease is Vibrio cholerae (cholera bacillus) - an aerobic gram-negative rod that produces a protein enterotoxin. Enterotoxin does not damage the intestinal wall, but it triggers processes in the intestine, as a result of which fluid, instead of being absorbed, begins to be intensively released into the lumen of the small intestine.
The typical form of cholera begins after an incubation period of 2-3 days. The disease manifests itself with all the characteristic symptoms.
With adequate therapy, the condition improves after a few days, the stool takes on a normal appearance, vomiting disappears, and appetite appears.
The severe form is the most dangerous. It develops very quickly, occurs with severe dehydration and can result in the death of the patient within 1-2 days.
The duration of the disease ranges from 2 to 7 days and depends on the adequacy of treatment with electrolyte solutions. Correct replacement therapy quickly leads to an improvement in the patient's condition. With inadequate treatment, death occurs from collapse, a shift in the body's acid-base balance towards increased acidity and kidney failure.
Symptoms
The disease begins acutely, with watery diarrhea and vomiting. In typical cases, stool is a cloudy white liquid with floating flakes, has no odor and resembles rice water in appearance.
Diarrhea and vomiting are accompanied by symptoms such as:
- decrease in body temperature to 34-35 degrees,
- general intoxication of the body,
- blackout,
- weakening of cardiac activity,
- loss of fluid with feces in the next few hours can reach 7-9% of body weight in severe cases, and in the most severe form of cholera - 10%,
- severe collapse develops,
- convulsions appear
- facial features become sharper,
- the skin acquires a cyanotic color (cyanosis), becomes flabby,
- the stomach is pulled in,
- thready pulse
- tachycardia appears,
- hypotension,
- dyspnea.
A blood test reveals an increase in erythrocytes, leukocytes with an increase in young and band forms, an increase in blood viscosity, a decrease in potassium to 2.5 mmol/l.
In mild cases of the disease, the symptoms are similar to foodborne infections, dysentery , rotavirus infection , and mushroom poisoning .
Atypical forms
Dry cholera
A severe form of cholera that occurs without diarrhea and vomiting. The intestines are full of fluid, but diarrhea does not develop. The patient dies from intestinal paresis and impaired body functions. This type of cholera is difficult to diagnose. It affects exhausted and weakened people.
Fulminant cholera
The most severe form of cholera, when all signs develop very quickly, within 2-3 hours, and death occurs.
Hemorrhagic cholera
A characteristic sign is the appearance of blood in the stool; the stool takes on the appearance of meat slop. This is due to the presence of concomitant diseases of the intestines, liver or stomach in the patient.
Erased form of cholera
The disease can occur in a mild form, in the form of ordinary diarrhea. Such a patient, being a source of infection, poses a great danger to others.
Diagnostics
The most difficult and responsible is the diagnosis of the first cases of the disease. In epidemic areas, if the above symptoms are present, cholera should be suspected first of all.
To identify Vibrio cholerae, stool samples are cultured on agar media containing bile salts or gelatin. After 24 hours, Vibrio cholerae forms large yellow colonies.
First aid
When the first signs of the disease appear, you should call a doctor.
Give the patient a sweet solution with the addition of 1 teaspoon of salt per liter of water. The solution should be warm, 36-38 degrees.
Treatment
Treatment must be carried out in a hospital setting.
In mild cases, fluid loss is replaced by the patient taking a rehydration solution. In severe cases, the solution is injected in a stream of 70-120 ml per second. The solution should be 36-38 degrees C. After restoration of normal pulse and skin turgor, the solution is continued to be administered in volumes equal to the lost fluid. Introducing less fluid leads to renal failure.
Hypokalemia is also a danger. Therefore, a blood test is performed and electrolytes (potassium salts, etc.) are replaced.
Rehydration should be carried out within 1-2 hours in a volume corresponding to the loss of body weight.
Antibiotics are not critical in the treatment of cholera patients. But in order to cleanse the body of cholera vibrio as early as possible, you can prescribe doxycycline 0.1 g every 12 hours on the 1st day and 0.1 g once a day for the next 3 days.
Vibrio carriers who secrete vibrio after recovery and suffer from concomitant infections and chronic diseases of the digestive system need antibiotic treatment. They are prescribed doxycycline at the dose indicated above or tetracycline 300 mg every 6 hours for 3-5 days.
Patients who have had cholera but are excreting vibrios are discharged after their recovery, completion of a course of antibacterial therapy and receipt of negative results of bacteriological examination.
Forecast
With proper treatment, the prognosis is favorable even in cases of severe cholera.
Prevention
- Compliance with hygiene standards and the use of clean water is of paramount importance. Particular caution should be observed in epidemiologically dangerous regions.
- It is necessary to thoroughly wash your hands, vegetables and fruits before eating.
- If a disease is detected, it is necessary to isolate the patient and disinfect all surfaces that he touched. It is advisable to disinfect the air in the toilet and bathroom. This can be done either with special lamps or aerosols.
- For 6 days, doctors monitor people who have been in contact with a sick person.
Vaccine
There is a vaccine against cholera. As a rule, it is recommended to do it in case of professional need.
The vaccine creates temporary immunity that lasts no more than six months and is effective in 60% of cases of infection.
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