Gastroenteritis

Gastroenteritis - inflammation of the mucous membrane of the stomach, small and large intestines. In most cases, these are infectious disease, although gastroenteritis can develop after taking medications and chemical toxic substances (eg, metals, substances of the industrial industry).

Symptoms of gastroenteritis include anorexia, nausea, vomiting, diarrhea, and abdominal discomfort. The diagnosis is established by clinical and bacteriological examination of the stool, although immunological studies have become increasingly common. Treatment of gastroenteritis is symptomatic, however, parasitic and some bacterial infections require specific antibiotic therapy.

Gastroenteritis usually causes some inconvenience, but can be resolved without treatment. The loss of electrolytes and fluids in gastroenteritis is slightly more important than the inconvenience associated with the disease for a healthy middle-aged person, but at the same time it can be quite a severe pathology for children and adolescents, the elderly or people with severe concomitant diseases. Worldwide, approximately 3-6 million children die each year from infectious gastroenteritis.

[1], [2], [3], [4], [5], [6], [7], [8]

What causes gastroenteritis?

Infectious gastroenteritis can be caused by viruses, bacteria or parasites.

Viruses

Viruses are the most common cause of gastroenteritis in the United States. They affect the enterocytes of the villous epithelium of the small intestine. The result is the transudation of fluid and salt into the intestinal lumen; sometimes carbohydrate malabsorption worsens symptoms, causing osmotic diarrhea. Diarrhea is watery. The most common inflammatory (exudative) diarrhea with the appearance in the stool of leukocytes and red blood cells, or even a significant amount of blood. Four categories of viruses cause most gastroenteritis: Rotavirus, caliciviruses [which include norovirus (previously called Norwalk virus)] astroviruses and intestinal adenovirus.

Rotavirus is the most common cause of sporadic severe cases of dehydration diarrhea in young children (the peak of the disease in children 3-15 months). Rotavirus is very contagious; most infections occur through the fecal-oral route. Adults may be infected after close contact with an infected infant. In adults, the disease is mild. Incubation is 1-3 days. In the temperate zone, most infections occur in winter. Every year in the US, the wave of rotavirus incidence begins in November in the southwest and ends in the northeast in March.

Caliciviruses usually affect adolescents and adults. Infection occurs throughout the year. Caliciviruses are the main cause of sporadic viral gastroenteritis in adults and epidemic viral gastroenteritis in all age groups; infection usually occurs through water or with food. Transmission from person to person is also possible, as the virus is very contagious. Incubation - 24-48 hours.

Astrovirus can infect people of any age, but usually affects babies and young children. As a rule, infection occurs in winter. Transmission occurs by the fecal-oral route. Incubation - 3-4 days.

Adenoviruses are the 4th, but the most common cause of viral gastroenteritis in children. Infection occurs year-round, with some increase in summer. Children under 2 years of age are primarily at risk of infection. Transmission occurs by the fecal-oral route. Incubation - 3-10 days.

In people with immunodeficiency, other viruses can cause gastroenteritis (eg, cytomegalovirus, enterovirus).

Bacteria

Bacterial gastroenteritis is less common than viral. Bacteria cause gastroenteritis with several mechanisms. Certain species (eg, Vibrio cholerae Vibrio cholerae, enterotoxogenic Escherichia coli are located within the intestinal mucosa and enterotoxins are secreted. These toxins interfere with absorption in the intestine, causing the secretion of electrolytes and water by stimulating adenylate cyclase, which leads to watery diarrhea. Clostridium difficile produces a similar toxin, which is the result of an overgrowth of microflora after the use of antibiotics.

Some bacteria (. Eg, Staphylococcus aureus, Bacillus cereus, Clostridium perfringens) produce exotoxin which enters into the body by receiving contaminated food. Exotoxin can cause gastroenteritis without bacterial infection. These toxins usually cause acute nausea, vomiting and diarrhea within 12 hours after ingestion of contaminated food. Symptoms of gastroenteritis disappear within 36 hours.

Other bacteria (. Eg, Shigella, Salmonella, Campilobacter, certain strains of E. Coli) penetrate the mucosa of the small intestine or the colon and cause the appearance of microscopic ulceration, bleeding, exudation of protein rich fluid secretion of electrolytes and water. The process of invasion may be accompanied by the synthesis of enterotoxin by microorganisms. With such a diarrhea in the feces contains white blood cells and red blood cells, sometimes with a lot of blood.

Salmonella and Campylobacter are the most common causative agents of bacterial diarrhea in the United States. Both infections are usually acquired through poorly treated poultry; sources of infection can be unpasteurized milk, undercooked eggs and contact with reptiles. Campylobacter is sometimes transmitted from dogs or cats suffering from diarrhea. Different types of Shigella are the 3rd major cause of bacterial diarrhea in the United States and are usually transmitted from person to person, but food poisoning epidemics are not excluded. Shigella dysenteriae type 1 (not detected in the US) produces Shiga toxin, which can cause hemolytic-uremic syndrome.

Some E coli subtypes can cause diarrhea. Epidemiology and clinical manifestations vary by subtype.

1. Enterohemorrhagic E coli is the most clinically important subtype in the United States. The bacterium produces Shiga toxin, which causes bloody diarrhea. E co // 0157: H7 - the most common strain of this subtype in the United States. Undercooked ground beef, unpasteurized milk and juice, polluted water are possible sources of transmission. Transmission from person to person is most common when caring for a patient. Hemolytic uremic syndrome is a serious complication that develops in 2-7% of cases, usually in children and the elderly.
2. Enterotoxic E coli produces two types of toxin (one of which is similar to cholera toxin), causing watery diarrhea. This subtype is a major cause of traveler's diarrhea.
3. Enteropathogenic E coli causes watery diarrhea. Previously, the subtype was the main cause of outbreaks of diarrhea in childcare facilities, but now it is rare. (4) Entero-invasive E coli is most common in developing countries and causes bloody diarrhea or diarrhea without blood. In the United States registered isolated cases.

Some types of other bacteria cause gastroenteritis, but they are rare in the US. Yersinia enterocolitica can cause gastroenteritis or appendicitis like syndrome. Infection occurs through poorly processed pork, unpasteurized milk or water. Some varieties of Vibrio (eg, V. Parahaemolyticus) cause diarrhea after consuming poorly processed seafood. V. Cholerae sometimes causes severe diarrhea in developing countries. Listeria causes gastroenteritis by eating contaminated food. Aeromonas affects the body when bathing or drinking polluted water. Plesiomonas shigelloides can cause diarrhea in patients who have consumed raw shellfish or traveled to tropical areas in developing countries.

[9], [10], [11]

Parasites

Certain intestinal parasites, especially Giardia lamblia, attach and invade the intestinal mucosa, causing nausea, vomiting, diarrhea and general malaise. Giardiasis occurs throughout the United States and throughout the world. Infection can occur chronically and cause malabsorption syndrome. Infection usually occurs from person to person (often in kindergartens) or through polluted water.

Cryptosporidium parvum causes watery diarrhea, sometimes accompanied by spastic abdominal pain, nausea and vomiting. In healthy people, self-healing can occur and the disease lasts for about 2 weeks. In immunocompromised patients, the disease can be severe, causing significant electrolyte and fluid losses. Cryptosporidium usually enters the body through contaminated water.

There are kinds of parasites, which include Cyclospora cayetanensis, Isospora belli, some organisms belonging to microsporidia (eg., Enterocytozoon bieneusi, Encephalitozoon intesfmalis), which can cause symptoms similar to the symptoms with cryptosporidiosis, especially in immunocompromised patients. Entamoeba histolytica (amebiasis) is the main cause of subacute diarrhea with blood in developing countries, sometimes diagnosed in the United States.

[12], [13], [14]

Symptoms of gastroenteritis

The nature, severity of the disease and the symptoms of gastroenteritis vary. In general, gastroenteritis develops suddenly, with anorexia, nausea, vomiting, rumbling, spastic abdominal pain and diarrhea (with or without blood and mucus). Sometimes there is malaise, myalgia and severe weakness. The abdomen may become swollen and painful on palpation; in severe cases, muscle tension may be present. On palpation, gas-swollen intestinal loops can be detected. Rumbling in the abdomen can be observed without diarrhea (an important distinguishing feature from paralytic intestinal obstruction). Constant vomiting and diarrhea can lead to intravascular fluid loss with hypotension and tachycardia. In severe cases, shock may develop with vascular insufficiency and oliguric renal failure.

If vomiting is the main cause of dehydration, metabolic alkalosis and hypochloremia develop. In the case of severe diarrhea, acidosis may develop. Both vomiting and diarrhea can cause hypokalemia. If hypotonic solutions are used as replacement therapy, hyponatremia may develop.

In viral infections, watery diarrhea is the main symptom of gastroenteritis; the stool rarely contains mucus or blood. Gastroenteritis caused by rotavirus in infants and small children can last 5-7 days. Vomiting occurs in 90% of patients, and fever is greater than 39 "C observed in approximately 30%. Caliciviruses usually show acute onset, vomiting, spastic abdominal pain and diarrhea lasting 1-2 days. In children, vomiting prevails over diarrhea, while diarrhea usually prevails in adults. Patients may experience fever, headache and myalgia. Symptom of adenoviral gastroenteritis is diarrhea lasting 1–2 weeks. Infection in infants and children is accompanied by slight vomiting that usually begins after 1-2 days. After onset of diarrhea. Mostly fever occurs in approximately 50% of patients. Astroviruses causes a syndrome similar to mild rotavirus.

Bacteria that cause invasive disease (eg, Shigella, Salmonella), as a rule, cause fever, severe weakness and bloody diarrhea. Bacteria producing enterotoxin (eg, S. Aureus, B.cereus, C. Perfringens) usually cause watery diarrhea.

Parasitic infections are usually accompanied by subacute or chronic diarrhea. In most cases, the stool is free of blood; an exception is E. Histolytica, which causes amoebic dysentery. Disturbance and weight loss are characteristic if diarrhea is constant.

[15], [16]

Diagnosis of gastroenteritis

Other diseases of the gastrointestinal tract, showing similar symptoms (eg appendicitis, cholecystitis, ulcerative colitis), should be excluded. Survey results suggesting gastroenteritis include profuse watery diarrhea; history of the use of potentially contaminated food (especially with an established outbreak of the disease), non-contaminated water or known irritating gastrointestinal tract substances; recent trip; or contact with people suspicious of the disease. E. Coli 0157: 1-17, which causes diarrhea, is notorious for being accompanied by a hemorrhagic process rather than an infectious process, manifesting symptoms the gastrointestinal bleeding, a small bloody stool or its absence. Hemolytic uremic syndrome may be due to renal failure and hemolytic anemia. Oral use in the history of antibiotics (for 3 months) should cause an additional suspicion of infection with C. Difficile. A suspicion of an acute abdomen is unlikely in the absence of abdominal muscular tension and limited soreness.

[17], [18], [19], [20], [21]

Chair studies

If a rectal blood test is detected during a rectal examination or if watery diarrhea persists for more than 48 hours, the test is shown. The occult blood sample is for feces for covered blood and the analysis is for feces (red blood cells in the stool, eggs, parasites) and bacteriological sowing. However, for the diagnosis of giardiasis or cryptosporidiosis, detection of the antigen in the stool by ELISA has a higher sensitivity. Using kits, you can diagnose infections of rotavirus and intestinal adenovirus by detecting a virus antigen in the stool, but these studies are usually performed only if an outbreak of the infection is documented.

All patients with bloody diarrhea should be examined for E. Coli 0157: 1-17, as well as patients with diarrhea without blood admixture with an established outbreak of the disease. It is necessary to carry out specific culture of the culture, since this microorganism is not detected by standard cultivation. Alternatively, an ELISA test can be performed to identify Shiga toxin in the stool; A positive test indicates the presence of an infection of £ coli 0157: 1-17 or one of the other enterohemorrhagic E. Coli serotypes. (Note: Shigella species in the US do not release Shiga toxin.)

Adults with severe bloody diarrhea should perform sigmoscopy with bacteriological culture and biopsy. Manifestations of the mucous membrane of the colon can help in the diagnosis of amoebic dysentery, shigellosis and infection £ coli 0157: 1-17, although such changes can be observed in ulcerative colitis. Patients who have recently taken antibiotics should have a stool test for C. Difficile toxin.

[22], [23], [24]

General analyzes

In severely ill patients, it is necessary to determine serum electrolytes, urea nitrogen, and creatinine to assess hydration and acid-base status. Indicators count are non-specific, although eosinophilia may indicate a parasitic infection.

[25], [26], [27], [28], [29], [30],

Gastroenteritis treatment

Supportive gastroenteritis treatment is all that is needed for most patients.

Bed rest with convenient access to the toilet or bedpan is desirable. Oral administration of a glucose-electrolyte solution, liquid food or broth prevents dehydration and is used as a treatment for mild dehydration. Even with vomiting, the patient needs to take these fluids in small sips: vomiting can decrease with a decrease in dehydration. In children, dehydration develops more quickly, therefore, it is necessary to prescribe appropriate repair solutions (some in free sale). Carbonated drinks and drinks for athletes have an insufficiently adequate ratio of glucose and Na and therefore are not recommended for children under 5 years of age. If the baby is breastfed, the feeding should continue. If vomiting is prolonged or severe dehydration develops, intravenous volume replenishment and electrolyte transfusion are indicated.

If there is no vomiting, the patient tolerates fluid intake and appetite appears, gradually you can begin to take food. There is no need to limit the diet to only light food (white bread, semolina porridge, gelatin, bananas, toast). Some patients may experience temporary lactose intolerance.

Antidiarrheal drugs are safe in patients older than 5 years with watery diarrhea (as evidenced by hemotnective stool). However, antidiarrheal drugs may cause worsening in patients with infection with C. Difficile or E. Coli 0157: 1-17 and they should also not be prescribed to patients after the use of antibiotics or with a hematopoietic stool without a definite diagnosis. Effective antidiarrheal agents include loperamide with an initial dose of 4 mg orally and subsequent ingestion of 2 mg orally with each episode of diarrhea (maximum 6 doses / day, or 16 mg / day); diphenoxylate 2.5-5 mg 3-4 times daily in tablets or in liquid form; or bismuth subsalicylate 524 mg (two tablets or 30 ml) orally in 6-8 hours a day.

In severe vomiting and in the case of exclusion of surgical pathology, the use of antiemetics can be effective. Drugs used in adults include prochlorperazine 5-10 mg intravenously, 3-4 times a day, or 25 mg into the rectum, 2 times a day; and promethazine 12.5-25 mg intramuscularly 2-3 times a day or 25-50 mg into the rectum. The use of these drugs in children should be avoided due to insufficiently proven efficacy and high propensity to develop dystonic reactions.

[31], [32]

Antibacterial drugs for gastroenteritis

Empirical antibiotics are generally not recommended except for certain cases of traveler's diarrhea or if there is a large suspected infection Shigella or Campylobacter (eg., Contact with a known carrier). Otherwise, the appointment of antibiotics should expect the results of bacteriological seeding of stools, especially in children who have a higher percentage of infection with E. Coli 0157: 1-17 (antibiotics increase the risk of hemolytic-uremic syndrome in patients infected with E. With // 0157 : 1-17).

With proven bacterial gastroenteritis, antibiotics are not always indicated. They are ineffective with Salmonella infection and prolong fluid loss from the stool. The exceptions are immunocompromised patients, newborns and patients with Salmonella bacteremia. Antibiotics are also ineffective in toxic gastroenteritis (eg, S. Aureus, B. Cereus, C. Perfringens). Indiscriminate use of antibiotics contributes to the emergence of resistant strains of microorganisms. However, certain infections do require antibiotics.

The use of probiotics, such as lactobacilli, is generally safe and can be effective for reducing the symptoms of gastroenteritis. They can be taken in the form of yogurt with an active culture.

When cryptosporidiosis in children with reduced immunity can be effective nitazoxanide. The dose is 100 mg orally 2 times a day in children 12-47 months and 200 mg orally 2 times a day in children 4-11 years.

[33], [34], [35], [36], [37]

How to prevent gastroenteritis?

Gastroenteritis is difficult to prevent because of the asymptomatic infection and the ease with which many people, especially viruses, are transmitted from person to person. In general, necessary preventive measures should be observed when communicating and preparing food. Travelers should avoid eating potentially contaminated food and beverages.

Breastfeeding provides some protection for newborns and babies. Nurses must wash their hands with water and soap after each change of diapers, and the working area should be disinfected with a freshly prepared solution of 1:64 household disinfectant (1/4 cup dissolved in 1 gallon of water). Children with diarrhea should be barred from attending daycare facilities until symptoms disappear. Before permission to visit the institution, children infected with enterohemorrhagic strains of E. Coli, or Shigella, should have two negative seeding stools.

[38], [39], [40], [41], [42]