E. coli infection is an acute, mainly intestinal infection caused by some serovars of the bacterium Escherichia coli. Escherichiosis manifests itself in the form of enteritis and enterocolitis, can be generalized and occur with extra-intestinal symptoms. The route of transmission of E. coli is fecal-oral. More often, infection occurs when eating infected dairy and meat products. A contact-household route of transmission of intestinal infection is also possible. The diagnosis of escherichiosis is established when escherichia is detected in vomit and feces, and when infection is generalized – in the blood. Treatment of escherichiosis consists of diet, rehydration therapy, the use of antimicrobials and eubiotics.
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E. Coli Infection (coli infections) is a group of infections caused by E. coli and occurring with lesions of the gastrointestinal tract, urinary tract, respiratory tract, meninges, bacteremia. They are more common in young children. Intestinal infections caused by escherichia are the most common: they are the most common cause of diarrhea in infants and adults. Some strains and their toxins cause life-threatening lesions of internal organs.
Escherichia coli (E. coli) is a short polymorphic gram-negative rod-shaped bacteria, non-pathogenic strains of which are present in the normal intestinal flora. Escherichiosis is caused by diarrheal serovars of the following groups:
- enteropathogenic (EPCB);
- enterotoxigenic (ETCB);
- enteroinvasive (EICB);
- enterohemorrhagic (EHCB);
- enteroadhesive (EACB).
Escherichia are stable in the external environment, can remain viable in soil, water and faeces for up to several months. In food products (especially in milk), they multiply, forming numerous colonies, easily tolerate drying. E. coli die during boiling and the action of disinfectants.
The reservoir and source of infection are sick people or healthy carriers. The greatest epidemic significance in the spread of the pathogen are persons with escherichiosis caused by types of EPCB and EICB, the remaining groups of bacteria are less dangerous. Patients with escherichiosis caused by infection with ETCB and EHCB are contagious only in the first days of the disease, while EICB and EPCB of the escherichia coli group are isolated by patients 1-2 (sometimes 3) weeks. The release of the pathogen can last for quite a long time, especially in children.
The mechanism of transmission of E. coli is fecal–oral, most often the food route of infection is realized for ETCB and EICB and household for EPCB. In addition, infection can be carried out by water. Food contamination mainly occurs when eating dairy products, meat dishes, beverages (kvass, compotes) and salads with boiled vegetables.
In children’s groups and among people who neglect the rules of hygiene, it is possible to spread E. coli through household contact through contaminated hands, objects, toys. Infection with pathogens of the EHPB group often occurs as a result of eating insufficiently cooked meat, raw unpasteurized milk. Outbreaks of escherichiosis caused by the use of hamburgers have been noted.
The implementation of the infection waterway is currently not widespread, infection of reservoirs with E. coli usually occurs when wastewater is discharged without preliminary neutralization. Natural susceptibility to escherichiosis is high, unstable group-specific immunity is formed after infection.
E. Coli Infection are classified according to the etiological principle depending on the group of pathogen (enteropathogenic, enterotoxic, enteroinvasive, and enterohemorrhagic).
- Escherichia of the EPCB group – mainly cause escherichiosis in children, especially in the first year of life. Outbreaks caused by this group of E. coli, as a rule, occur in nurseries, kindergartens, maternity hospitals and children’s departments of hospitals. Infection usually occurs by contact and household means.
- Sticks of the EICB group cause enterocolitis, occurring by the type of dysentery in children older than one year and adults. Infection occurs by water and food, the summer-autumn seasonality is noted. They are mainly distributed in developing countries.
- ETCB cause cholera-like infections, children from two years old and adults are infected, the incidence is high in countries with a hot climate and low hygienic culture. Infection occurs by food and water.
- Epidemiological data on infections resulting from the defeat of the pathogen of the EHCB group are currently insufficient for detailed characterization. In the epidemiology of escherichiosis, the main importance is played by hygienic measures, both of a general and individual nature.
There is a clinical classification that distinguishes gastroenteric, enterocolitic, gastroenterocolitic and generalized forms of the disease. The generalized form can be represented by coli-sepsis or Escherichia coli lesion of various organs and systems (meningitis, meningoencephalitis, pyelonephritis, etc.). Escherichiosis can occur in mild, moderate and severe forms.
E. Coli infection symptoms
Class I EPCB usually develops in young children, the incubation period is several days, manifested mainly by vomiting, loose stools, severe intoxication and dehydration. There is a possibility of developing a generalized septic form. Adults get sick with class II EPCB, the disease proceeds according to the type of salmonellosis.
The defeat of EICB is characterized by a course like dysentery or shigellosis. The incubation period lasts from one to three days, the onset is acute, there is moderate intoxication (headache, weakness), fever ranging from subfebrile to high values, chills. Then there are abdominal pains (mainly around the navel), diarrhea (sometimes with streaks of blood, mucus). Palpation of the abdomen marks soreness along the course of the colon. Often, escherichiosis of this type occurs in a mild and erased form, a moderate course may be noted. Usually the duration of the disease does not exceed several days.
The defeat of ETCB may manifest clinical symptoms similar to those of salmonellosis, food poisoning, or resemble a mild form of cholera. The incubation period is 1-2 days, intoxication is poorly expressed, the temperature usually does not rise, there is repeated vomiting, abundant enteric diarrhea, dehydration gradually increases, oliguria is noted. There are pains in the epigastric region, having a cramping character.
This infection is often called “traveler’s disease”, because it often affects people who have gone on a business trip or on vacation to countries with a tropical climate. Climatic conditions contribute to the occurrence of severe fever with chills and intoxication symptoms, intense dehydration.
EHCB develops most often in children. Intoxication is moderate, body temperature is subfebrile. There is nausea and vomiting, liquid watery stools. With a severe course by day 3-4, severe abdominal pains of a cramping nature appear, diarrhea increases, and an admixture of blood and pus may be noted in the feces that lose their fecal character.
Most often, the disease goes away on its own after a week, but with a severe course (especially in young children) on day 7-10, after the disappearance of diarrhea, there is a possibility of developing hemolytic-uremic syndrome (a combination of hemolytic anemia, thrombocytopenia and acute renal failure). Disorders of brain regulation are not uncommon: convulsions of limbs, rigidity of muscles, disorders of consciousness up to sopor and coma. The mortality rate of patients with the development of these symptoms reaches 5%.
Usually e. coli infection are not prone to complications. In the case of infection provoked by the pathogen of the EHCB group, there is a possibility of complications from the urinary system, hemolytic anemia, cerebral disorders.
To diagnose e. coli infection, the pathogen is isolated from feces and vomit, in cases of generalization – from blood, urine, bile or liquor. After that, a bacteriological study is carried out, sowing on nutrient media. Due to the antigenic similarity of escherichiosis pathogens with bacteria that are part of intestinal normocinosis, serological diagnosis is not informative enough.
For laboratory diagnostics of infections caused by EHCB, the detection of bacterial toxins in the feces of patients can be used. With this type of escherichiosis, signs of hemolytic anemia, an increase in the concentration of urea and creatinine may be noted in the blood test. Urine analysis usually shows proteinuria, leukocyturia and hematuria.
Treatment is mainly outpatient, patients with severe forms and a high risk of complications are hospitalized. A diet is recommended for patients. For the period of acute clinical manifestations (diarrhea) – table No. 4, after termination – table No. 13. Moderate dehydration is corrected by taking liquid and rehydration mixtures orally, with an increase and a pronounced degree of dehydration, intravenous infusion of solutions is performed. Pathogenetic treatment is chosen depending on the type of pathogen.
As antimicrobial therapy, drugs of the nitrofuran series (furazolidone), or (in severe infection caused by EICB) fluoroquinolones (ciprofloxacin) are usually prescribed. The drugs are prescribed for 5-7 days. Treatment of escherichiosis of EPCB in children should be carried out using a combination of sulfamethoxazole and trimethoprim, antibiotic therapy. Generalized forms are treated with cephalosporins of the second and third generations.
Enzyme preparations and eubiotics are included in complex therapy for a prolonged course of the disease to normalize digestion and restore intestinal biocenosis. Modern principles of treatment of escherichiosis provoked by bacteria of the EHCB group include the use of antitoxic therapeutic measures (serums, extracorporeal adsorption of antibodies).
The prognosis for adults and older children is favorable, with a mild course, cases of independent recovery are noted. Young children may suffer from severe escherichiosis, which worsens the prognosis. Recovery is also noticeably more difficult in the case of generalization and the development of complications. Some particularly severe forms of e. coli infection can end in death without proper medical care.
E. coli infection is a disease associated with a low hygienic culture. Personal prevention of these infections consists in following hygienic standards, especially when communicating with children, washing hands, food, toys and household items. General prevention is aimed at monitoring compliance with the sanitary and hygienic regime in children’s institutions, food industry enterprises, medical and preventive institutions, as well as monitoring the flow of sewage waste and the condition of water sources.
Patients after e. coli infection are discharged from the hospital after clinical recovery, as well as according to the results of a three-time bacteriological test. Admission to the team of children who have been in contact with the patient is also carried out after a bacteriological diagnosis and confirmation of the absence of isolation of the pathogen. Persons who secrete pathogenic escherichia are subject to isolation for the entire period of contagiousness. Food industry workers are subjected to regular examinations for the release of the pathogen, in case of a positive test, they are suspended from work.