- Prevalence of
- Infection mechanism
- Properties of pathogens
- How does the pathology develop?
- Phases of Shigellosis
- How does dysentery manifest?
- Clinical forms of
- What are the possible complications?
- How to treat dysentery?
- Related Videos
Many people know that dysentery is an infectious disease, part of the "intestinal infections" group. And this means that it is caused by a particular pathogen, the manifestations necessarily include the clinical symptoms of dysentery in adults and children with lesions of the small and large intestine. There are known light and severe forms of the disease, asymptomatic carriage of dysentery, damage to internal organs.
The most dangerous causes of dysentery are pathogenic microorganisms of two types: amoeba and shigella. Accordingly, the infectious diseases caused by them, are called amebiasis and shigellosis. The course of amoebic lesions and shigellosis dysentery have common signs and differences, require accurate diagnosis and the choice of optimal treatment.
In the structure of acute intestinal infections, shigellosis type dysentery accounts for 54-75%.1/10 of the population is infected with amebiasis. The total number of deaths from dysentery is up to 1 million people per year. The maximum incidence in countries with warm and hot climates. And in the zone of temperate latitudes - in the summer months. A huge permanent source of pathogens are India, Mexico, and other countries in Central and South America.
Most patients with dysentery( up to 60% of all cases) are children under the age of 4 years. More details about the features of infection and the course of the disease in children can be found in this article.
Because immunity after dysentery is very short( from four to 12 months), there remains the possibility of recurrence of the disease.
The mechanism of infection of
The source of the disease is sick people or carriers of infection, formed due to mild cases of dysentery, a mild symptomatology that is not paid attention. Amoeba cysts can be carried by insects. Differences between amoebic dysentery and shigellosis by the mechanism of transmission are not revealed.
Infection of a healthy person with dysentery occurs through dirty hands, shortages of water supply, purification systems, sewerage, feces contaminated food, water, with homosexual contact. The duration of the infectious period in the patient is from one to three weeks. There are studies that prove that people with a second blood group are the most sensitive.
Properties of pathogens
Amebiasis is associated with a pathogen of the "Protozoa" class. Amoebas of dysentery exist in 3 forms:
- in the patient - in the tissue;
- in carriers - in the luminal( vegetative) and cystic.
Have a core and pseudopods for movement. Eat "swallowing" of other bacteria, fungi, food debris. The cyst is round in shape, with several cores. In the small intestine of a person infected with human dysentery, the cyst shell is ruptured. From it comes a mature amoeba, which begins to multiply by dividing into single-nuclear vegetative forms.
It was at this time that the first symptoms of the disease appeared. Increasing quantitatively, they move deeper into the intestine, secrete toxic substances that cause symptoms of poisoning. With feces the vegetative forms and cysts of dysentery amoeba go into water, land, settle on unwashed objects of everyday life.
The causative agent of amoebic dysentery has sufficient resistance to disinfection facilities, it is able to maintain its infectiousness for a long time.
Bacterial dysentery is caused by special chopsticks, which in honor of the one who discovered one of the Japanese scientist Shiga are called shigella. They are gram-negative in color. Are able to live without oxygen. Exo-and endotoxins are isolated. Immobile, flagella used to attach to the wall of the gut. Can not form disputes.
Shigella are weakly stable in the external environment, destroyed by ultraviolet in a few minutes, in feces last no more than 10 hours( neutralized by another flora), for half an hour they die under the influence of disinfectant solutions.
The international classification of dysentery in 1982 distinguishes 4 main types, each of which has subtypes( serovars).All are capable of releasing endotoxin with a specific effect on the intestine and nerve cells, increasing temperature, enzymes, active substances.
The causative agents of bacterial dysentery differ in properties and pathogenicity:
- Shigella Grigorieva-Shiga - maximally produces exotoxin, therefore causes the most severe form of dysentery with damage to water-salt metabolism, central nervous system activity, cell death of the large intestine. Some authors call it a neurotoxin. The disease can cause even 10 microbial cells. In the early twentieth century had the character of epidemic outbreaks. Now in the developed countries almost does not occur.
- Shigella Flexner - has the strength of pathogenicity is 10 times lower than Grigoriev-Shiga, it has considerable stability in the environment( in the soil up to 5 months in winter, 3 months in water bodies).Therefore, the main transmission path is water. A heavy current was observed in the 40s of the twentieth century.
- Shigella Boyda - circulates in the region of India, Pakistan, has 18 serotypes.
- Shigella Sonne - although for sufficient infection, a dose of 10 million cells is needed, the disease is considered the most stable. Occurs in erased asymptomatic or mild forms, dangerous for bacterial transport. Transmitted mainly through contaminated products( milk).Outbreaks of infection were observed in the 1980s.
The incidence reflects the health status of
Currently, 96% of cases of dysentery in large cities are caused by Shigella Flexner. Type of dysentery Sonne is typical for rural areas. It is established that any shigella contain an R-factor that determines resistance to antibiotics.
Multiple resistance is provided by bacteria in which plasmids are found. They have the maximum infectiousness. Scientists express an opinion on the dependence of the changes in the types of the causative agent of dysentery on the development of immunity in humans.
How does the pathology develop?
The gastrointestinal tract is the gateway to infection and the breeding ground for microorganisms. Dysentery amoebae with infected products through the stomach pass through the blind and ascending colon. Here, in the form of cysts, they can be stored for a long time and do not manifest themselves. If a person is exposed to unfavorable conditions( hunger, dehydration, dysbacteriosis, falling immunity), then the cysts are quickly released from the envelope, a luminary form emerges and begins to divide.
Amoebas spread to the lower intestine. Their proteolytic enzymes cause inflammation, ulcers and necrosis of surrounding tissues. The sites of ulceration reach up to 2.5 cm in diameter. The bottom of the ulcer is covered with pus. In the study of tissue biopsy, a vegetative form of the causative agent of dysentery is found in it.
If the process develops slowly and takes a chronic course, the morphological sign of dysenteric lesion in an adult person is cysts, polyps and amebae( tumor-like formations consisting of a clump of cells of eosinophils, granulocytes, fibroblasts).The extra-intestinal form with amoebic dysentery is most often associated with the formation of abscesses in the liver, rarely in the brain and other organs.
In shigellosis the main factor of pathology is endo- and exotoxins. They affect the digestive organs, the nervous system, the heart, the adrenal glands. Bacteria of dysentery can stay in the stomach for a few days, overcome the acid reaction, then with food advance into the intestine.
The fixation on the wall takes place in the small intestine
. In the small intestine, the release of toxins begins, the production of fluid and salts with the release into the lumen of the intestine increases. Spreading through the intestines causes and supports an inflammatory reaction, getting into the blood, toxins contribute to general intoxication. The transition to the large intestine is accompanied by a massive release of toxins, a serious condition of the patient.
During recovery, the body is released from the dead pathogens of dysentery, their remains. If immunity is not enough, then the period of purification is significantly increased, the disease can go into a chronic course, form a carrier.
Phases of shigellosis
Symptoms of dysentery caused by shigellosis are formed due to the two phases of the inflammatory process.
The main factors are the factors of natural resistance of the body:
- the presence of lysozyme in saliva and mucus;
- hydrochloric acid of gastric juice;
- condition of the intestinal wall;
- activity of intestinal flora( the causative agent of dysentery is exposed to other bacteria of the gut).
Depending on these factors, the following options are possible:
- penetrated pathogens of dysentery are destroyed by natural protection factors, the disease is absent;
- pathogenic microbes pass the intestines, without causing changes, and exit into the external environment( a transitory bacteriocarrier is similarly formed);
- penetrating into the end portion of the small intestine into the wall, microorganisms secrete toxins and cause inflammation and intoxication.
In the latter case, the development and severity of shigellosis symptoms depends on the massiveness of the resulting dose of cells. If the patient receives a lot of shigella with food, then the clinical picture of dysentery is caused by an "explosion" of toxin secretion and is accompanied by the shortest incubation period, vivid manifestations of intoxication, predominance of symptoms of defeat of the stomach and small intestine( gastritis, gastroenteritis).
How large the lesion area of the large intestine depends on the protective forces of the patient. In immunodeficiency, the entire intestine is involved in inflammation. Shigella penetrate into the interior of epithelial cells, they multiply and destroy structures, forming areas with necrotic tissues.
Grigoriev-Shiga dysentery is accompanied by penetration of pathogens into lymphatic vessels and nodes. But more often there is only a local inflammatory process, not spread throughout the body.
The pain is caused by toxins on the lymph and blood circulation, the damage to the nerve plexuses of the bowel, the frequent loose stool
. The pains differ in nature, depending on the type of lesion of the muscle fibers. With the contraction of the circular muscles, the upper parts of the intestine are overflowing, and the underlying ones are emptied, the pains are of the nature of spasms, of false desires, there is little feces, the contents of the feces are mucus, the products of inflammation.
If the longitudinal muscles contract, longer pain, painful, false desires do not pass after the act of defecation. Defects of the mucosa are caused by a dysentery disorder in protein synthesis, increased epithelial sloughing. The general effect of toxins contributes to:
- development of intoxication( at a severe degree to toxic shock), toxins are carried by blood in organs and tissues, causes the centers of vegetative innervation in the brain, at the level of the nodes of the abdominal cavity, segments of the spinal cord;
- inhibition of the sympatoadrenal system of the adrenal gland occurs, the primary action of the vagus nerve creates the conditions for pressure drop, frequent defecation;
- due to digestive and renal dysfunction, all types of metabolism change, water and electrolytes are lost to the degree of dehydration, a lack of vitamins, proteins and carbohydrates provokes a violation of the assimilation of oxygen by cells, the synthesis of energy.
In severe dysentery, the bowel wall is destroyed, the body is further poisoned by necrotic tissues. Patients lose a significant amount of protein. Capillaries around the site of inflammation are thrombosed, further impairing nutrition of the muscular layer.
Paresis develops( immobilization).There are conditions for perforation of the intestine. Because of the violation of the flora in humans, secondary immunodeficiency occurs. Particular importance in the development of dysentery is given to autoimmune processes. Reorganization in response to toxins-antigens causes the formation of antibodies to the epithelium of the colon.
The process reaches a maximum in the second week of the disease. The increased release of histamine, acetylcholine, and serotonin into the blood increases the inflammation even more. Allergization is higher in patients prone to the transition to chronic dysentery.
How does dysentery manifest?
Usually signs of the disease appear 2-3 days after infection. Rarely is the period prodroma in the form of cognition, weakness, headache, incomprehensible indisposition. More often, the onset of acute: almost simultaneously, the temperature rises, there are pains in the abdomen and disorders of the stool. On the second day, headaches, weakness, local symptoms from the intestinal tract increase.
The duration of the fever period is usually 3 days
For the average severity of the disease is characterized by:
- chills and a fever of 39 degrees;
- loss of appetite and nausea;
- rumbling of the abdomen, bloating;
- cramping pain more often in the left ileal region and above;
- liquid stool up to 20 times a day, feces are replaced by mucus, blood, pus, the volume decreases( symptom "spitting");
- patients are concerned about the urge to defecate, which turn out to be false and are not supported by feces;
- tongue covers a thick coating;
- is characterized by pale skin;
- heartbeat, decreased pressure.
When palpation of the abdomen, a spasmodic intestine is found in the form of a dense painful cushion in the ileum zone to the left. The period of severe intoxication lasts up to five days. The chair can be normalized by the tenth day, but the other symptoms still remain 3-4 weeks.
With amoebic dysentery, the incubation period is longer( about a week).The onset is acute, patients are worried about the increase in weakness, abdominal pain on both sides, fever. In every tenth case, the current is lightning fast - strong diarrhea with blood and mucus, dehydration, death threat.
In 30% of patients, fever is associated with an increase in liver size. With the simultaneous growth of the spleen, differentiation is carried out with malaria. Extrahepatic manifestations manifest themselves as accumulation of pathogens. Sometimes patients are treated with an already formed liver abscess.
Clinical forms of the
flow Not all symptoms are always very pronounced. According to clinical manifestations, 3 forms of dysentery are isolated.
Patients experience a short-term temperature increase of not more than 38 degrees. Pain in the abdomen is moderate, preceded by an act of defecation, feces of a semi-fluid consistency 10 times a day, mucus and blood there. Diarrhea lasts no longer than three days, recovery occurs after 2-3 weeks.
Symptoms correspond to the described vivid manifestations. The nervous system reacts by increasing irritability, insomnia. Diarrhea occurs after 4-5 days. The patient recovers after a month and a half.
Differs by the rapid development of symptoms, pronounced intoxication, a reaction from the cardiovascular system. Simultaneously, the patient has severe headaches, the temperature increases to 40 degrees, chills, dizziness, loss of appetite.
Possible nausea, vomiting, frequent painful urge to defecate, hiccough. Symptoms last up to 10 days.recovery is a slow pace 2 months. If the disease lasts more than three months, the diagnosis is "chronic dysentery."
Diagnostics actively use methods of bacterial inoculation, immunological methods
What are the possible complications?
Infection leads to a complicated course of pathology. Most often, when dysentery occurs:
- dehydration and infectious-toxic shock;
- toxic brain damage;
- perforation of the gut and peritonitis;
- acute heart failure;
- bleeding from the intestine;
- toxic colon dilatation;
More rarely observed:
- cracks the anus;
- prolapse of the rectum;
- autoimmune polyarthritis;
- relapsing course of the disease.
How to treat dysentery?
For mild forms of illness, bed rest is not necessary. Treatment of dysentery in adults and children, beginning with the moderate form should be carried out in the infectious ward of the hospital. The food in the acute period corresponds to the diet table No. 4, after taking the intoxication patients are transferred to the table number 2, and before discharge - to the general.
By volume, drenching the liquid should exceed the loss by 1.5 times
With loss of fluid, a plentiful drink of water, sweet tea, rosehip broth is shown. At home, it is recommended to abstain for 2-3 more months from sharp and fried foods, fats, legumes, which greatly irritate the intestines. For the treatment of shigellosis, short courses of antibacterial agents( 4-5 days) are chosen, preferably taking into account the sensitivity. With severe form of dysentery, two antibiotics and a longer application may be required.
Usually selected from drugs that have a specific effect on the pathogens( nitrofurans, Ersefuril, Cotrimoxazole, oxyquinolines).Doses are selected depending on the severity of the condition, weight and age of the patient. In the treatment of amoebic dysentery, cytostatics are actively used( Metronidazole, Tinidazole).With extraintestinal forms, Metronidazole is administered in combination with Yatren, Meksaform, Doydohin.
Sometimes it is necessary to decide on surgical intervention. To compensate for the water-electrolyte balance intravenously injected saline solutions, albumin, Trisol, Acesol, Regidron is prescribed inside. Intravenously injected protein preparation Hemodez for the removal of intoxication.
For shigellosis type Flexner and Sonne used polyvalent dysentery bacteriophage in tablets or liquid form. To improve the excretion of toxins show enterosorbents( Polyphepanum, activated carbon, Enterodez, Polysorb, Smecta).Neutralizing action is exerted by enzymes( Pancreatin, Festal).
As symptomatic agents are used:
- antispasmodics for pain relief;
- antihistamines to reduce the allergic mechanism of inflammation;
- vitamins and probiotics for the restoration of intestinal flora and immunity;
- immunostimulants( Timalin, Levamisol, Dibasol) are necessary to activate their own protective forces.
Known hypertensive patients Dibazol is also used to stimulate the immune system
In order not to develop dysentery, one should not forget about observing preventive measures for mandatory washing of hands, vegetables and fruits, and proper culinary processing of products. In the heat, you should drink only boiled water from your dishes.
Special vaccination of the population is not carried out due to the lack of the possibility of forming a permanent immunity. The main symptoms of the disease should be known to adults. Dysentery is important to cure, to prevent the patient's infectiousness for others and to save him he undesirable consequences for his own intestines.