Cholera is among the most dangerous bacterial infections that is epidemic. South-East Asia, Latin America, India, Africa - in these countries there are endemic centers and reservoirs of virulent strains of the pathogen, which is explained by the favorable conditions for the bacterial reproduction and life of the bacteria, as well as the presence of a large amount of water for transmission.
At the same time, cases of infection are characteristic of countries with moderate climates, while epidemics are peculiar in conditions of tropical climate.
The disease is characterized by severe symptomatology and high mortality. WHO provides data that in 2010, the number of infected was between 3 and 5 million people, while the disease died from 100-130 thousand. The discrepancy in the calculated indicators is observed due to the fact that in tropical countries and regions with The poorly developed system of providing medical care for patients sick people died without receiving it, and therefore cases of the disease were not registered.
As a pathogen of bacterial infection, the cholera vibrio, which has two biowars of virulent serogroup O1, stands for. The first is the cholerae, which in modern times rarely causes the disease. The second one is velton eltor, which is characterized by higher virulence and resistance in the environment, due to which this type causes the majority of cases of illness, and, consequently, epidemics.
The bacterium is transmitted by the fecal-oral route, which causes the presence of endemic foci in the tropics. From bacteria infected with feces the intestines enter the aquatic environment, which remains virulent for about a month. Therefore bathing in ponds, drinking raw water and using unwashed dishes allows bacteria to enter the body. This is not always possible development of the disease, because vibrium is viable in alkaline environment. The acidic stomach is a natural biological barrier, and therefore most of the cases are associated with a large number of pathogens, or with pathologies of the organ that lead to a decrease in the production of acid.
Symptoms of cholera
The pathogenetic mechanism of the disease is associated with the action of cholera enterotoxin, which affects sodium receptors of the epithelial cells of the small intestine. By disturbing their functioning, the main symptoms of cholera are revealed: hypersecretion of sodium ions into the gut lumen, which leads to profuse diarrhea. Due to its water is rapidly lost from the body, resulting in systemic violations. In this case, enterotoxin is specific to sodium receptors in humans, so only people suffer from cholera.
By degree of severity, three types of cholera are distinguished: severe, moderate, and also mild.
With a slight degree of symptoms of cholera include one-time vomiting, a liquid stool, a loss of fluid in the ratio of 1-3% of the actual body weight. 1-2 days later, as the vibration from the organism is eliminated, the disease is stopped.
Symptoms of moderate cholera include:
- Profuse diarrhea 15-20 times per day;
- Feces in the form of a cloudy liquid that is not stained with bile pigments (feces in the form of a rice broth);
- Acute abdominal pain;
- False defecation claims.
The degree of dehydration in this case is 4-6% of the body weight.
At a severe course of the course, similar symptoms of cholera, which lead to dehydration of the 3rd degree, are characteristic. The ratio of the lost fluid is 6-9% of the body weight. There is marked dyspnea, cyanosis of extremities, reduction of skin turgor, convulsions. Unlike the average severity, the pain syndrome is poorly expressed: pain in the catapult and epigastric areas is dull.
Cholera diagnosis is conducted taking into account the endemic nature of the disease, the popularity of the epidemic in the target area, as well as in the patient's examination and interview. He can report that he has become infected after drinking water or bathing. Specific symptoms: feces staining, defecation frequency, dehydration, thirst.
Diagnosis of cholera in sporadic cases is intended to clarify the biowar and serotype of the pathogen. This is done after sowing stomach and microscopy. Also, clarification of the pathogen can be carried out by the method of polymerase chain reaction.
Immunological methods use the agglutination reaction using specific serums.
The purpose of diagnosis of cholera is the differentiation between salmonella, dysentery Zonne, viral diarrhea, botulism, poisoning of water FOS, gastroenteritis associated with an intestinal stick, poisoning with mushrooms.
The severity of the patient's condition is a leading factor in the treatment of cholera.
At a mild degree, the disease can go on its own, although the patient is a distributor of vibrio in the medium. To eliminate it, doxycycline (300 mg dose, used once for any severity of the course) is used.
With an average and severe needs correction of fluid and electrolyte balance of the body, detoxification, antibiotics accordance with the above principle. Symptomatic cholera treatment includes infusion of electrolyte solutions. They should fill the losses of sodium, potassium, chlorine and glucose. Ringer-Locke solutions, separate infusions of saline solution and glucose 5% are used. As enterosorbents activated charcoal is used, Preparations "Podifepan", "Smecta".
After recovery, all symptoms of the disease disappear. Elimination of the pathogen passes through 7-14 days from the moment of the disappearance of the clinic.
Specific effects of cholera are uncharacteristic, fully restoring the patient's performance, the prognosis of treatment is favorable. Duration of therapy in severe course is 30 days, without treatment, the likelihood of death is very high.
Prevention of cholera is individual and social in nature. In the first direction, the most effective vaccination before traveling to a tropical country.
Vaccines are used:
- WC/rBS - contains killed cells of Cholerae O1 vibrio with modified non-pathological anatoxin, obtained by genetic engineering methods. The effectiveness of preventing infection is 85-90%.
- CVD 103-HgR - contains virilent weakened vibrio cells. Efficiency - 95%, re-entry protects from El Tor's cheat sheet - 65%.
- Modified WC/rBS - contains weakly vibrational cell vibrio. Take 2 doses with a weekly break. Has low efficiency, cheap, licensed only for Vietnam.
Individual prophylaxis of cholera involves observance of sanitary norms: hand washing, bed linen. In endemic cells you can not swim in water bodies.
Public prevention is aimed at disinfecting frequently visited places and water, preventing the spread of infection, eliminating reservoirs.
Cholera is one of the diseases that, despite the careful elaboration of medical measures, is epidemic. The high mortality rate persists in tropical countries, with the epidemics also characteristic of the United States, despite the development of medical care. Therefore, if you go to a tropical region, regardless of the country, it makes sense to have a vaccine prophylaxis. Its validity is 2-3 months, so when you leave it again it is again necessary to conduct. Also, while staying in a tropical country, doxycycline should always be present in the first aid kit.