Rotavirus Enteritis

What is Rotavirus Enteritis?

Rotavirus enteritis – an acute viral disease with a predominant disease of children; characterized by symptoms of general intoxication, lesion of the gastrointestinal tract, dehydration.

Causes of Rotavirus Enteritis

The pathogen belongs to the family of Reoviridae, the genus Rotavirus. The name rotavirus received from the Latin rota – wheel, as viral particles under an electron microscope look like small wheels with a thick sleeve, short spokes and a thin rim. Icosahedral virion, 65 – 75 nm in diameter. Capsid is double-layered, built in cuboid type. Contain RNA.

Human rotaviruses can be cultured in green monkey kidney cells. According to antigenic properties, rotaviruses are subdivided into 9 serological types, of which types 1–4 and 8–9 are found in humans, types 5–7 are distinguished from animals. Rotaviruses of animals (dogs, cats, horses, rabbits, mice, calves, birds) for humans are not pathogenic. Rotaviruses are resistant in the environment.

Epidemiology
The disease is widespread in many countries around the world, accounting for about half of all intestinal disorders in children in the first two years of life in developing countries. In the United States, over 1 million cases of severe rotavirus diarrhea are observed annually among children aged 1 to 4 years, and in 150 patients the disease is fatal. In 90% of older children, anti-thorn virus antibodies are found in the blood, which indicates a wide spread of this infection.

Antibodies against rotaviruses 1 and 3 serotypes prevailed in Germany and Japan. In different years, different serotypes may prevail in the same country. So, in Australia in 1975, the rotavirus of serotype 3 prevailed, in 1977 and 1978 – of serotype 2, and in 1980 and 1986, the rotavirus of serotype 1 was detected.

Children under the age of 3 years, both in developed and developing countries, are more likely to become ill. Rotaviruses account for 30–50% of all cases of diarrhea requiring hospitalization and rehydration therapy. Adults in families where a child is sick often also get sick, and elderly people with a weakened immune system also become ill.

Rotavirus infection accounts for about 25% of cases of so-called traveler diarrhea. Rotavirus infection can be asymptomatic, such cases are often detected in newborns. Such a course further protects children from severe rotavirus gastroenteritis during the first 3 years of life.

The reservoir and sources of the pathogen: a person, patient or carrier. Cross-antigenic bonds between rotaviruses of humans, monkeys and calves have been found, however, the epidemiological significance of animal viruses has not been established.

Rotaviruses are found in the water of rivers, lakes, seas, and in groundwater. The pathogen is excreted with feces (1 g of feces contains up to 10-10 viral particles) for up to 3 weeks (more often 7-8 days from the onset of the disease).

The mechanism of transmission of the pathogen is fecal-oral; transmission routes – water, food, household. The possibility of implementing an airborne or airborne dust transmission path is presumable.

In tropical countries, rotavirus infection occurs year-round with some increase in incidence during the cool rainy season. In countries with a temperate climate, seasonality is quite pronounced with the highest incidence in the winter months.

A person is infected with alimentary. Reproduction and accumulation of reovirus occurs in the upper gastrointestinal tract, in particular in the duodenal epithelium. The absence of severe fever and symptoms of general intoxication (in the absence of information about viremia) suggests that the hematogenous route of dissemination of rotaviruses is not significant.

Pathogenesis during Rotavirus Enteritis

Rotaviruses cause the death of mature cells of the small intestine, they are replaced by immature absorbing cells that are unable to adequately absorb carbohydrates and other nutrients, which leads to osmotic diarrhea.

Intracellular metabolism of cyclic adenosine monophosphate or guanosine monophosphate is not important in the pathogenesis of rotavirus diarrhea.

Rotaviruses accumulate in the intestinal mucosa and then enter the intestinal lumen. Large losses of fluid and electrolytes are pathogenetically important, which leads to dehydration, usually no more than II-III degrees. Small amounts of rotaviruses have also been found in the colon.

Rotavirus infection is often combined with other viral (adeno- and coronaviruses) and bacterial (Escherichia, Shigella, Salmonella, Campylobacter) agents. However, rotaviruses themselves can cause damage to the gastrointestinal tract, which has been proven in animal experiments.

Pathological picture
Microscopic examination of the mucous membrane of the small intestine reveals areas with a smoothed surface, shortened villi, infiltration of the mucous membrane by mononuclear cells is noted. Rotavirus particles can be detected with electron microscopy. After 4-8 weeks, the mucous membrane of the small intestine is completely normalized.

With rotavirus disease, the epithelium of the villi of the small intestine is partially destroyed, in which the synthesis of disaccharidases occurs. As a result, uncleaved disaccharides accumulate in the intestine. The process of absorption of simple sugars is also disrupted. All this leads to an excessive flow of disaccharides and simple sugars into the large intestine, which leads to an increase in osmotic pressure. In this regard, fluid flows in large quantities from the tissues into the colon, which can lead to dehydration syndrome. This process is exacerbated by inflammation caused by rotavirus infection.

Immunity
In most cases, it occurs in early childhood after an illness. Immunity is unstable, so in adults with low antibody levels, the disease can recur. Immunity in those who have recovered is due not only to humoral, but also secretory antibodies.

Symptoms of Rotavirus Enteritis

The incubation period lasts from 15 hours to 7 days (usually 1-2 days). The disease begins acutely. A detailed picture of the disease is formed within 12-24 hours from the onset of the disease. In most of the hospitalized children, the body temperature reaches 37.9 ° C and above, and in some it can rise to 39 ° C and above. In mild forms of the disease, both in adults and in children, severe fever does not occur. Patients report pain in the epigastric region, nausea, vomiting.

On examination, hyperemia of the pharynx, signs of rhinitis, and an increase in cervical lymph nodes are often noted. However, the most typical manifestations of the disease are symptoms of damage to the digestive system.

Characterized by abundant watery watery stool without admixture of mucus and blood. A more severe course is usually caused by a layer of secondary infection. Half of the patients have vomiting. In adult patients, against the background of moderate intoxication and subfebrile temperature, pain in the epigastric region, vomiting and diarrhea appear. Only in some patients, vomiting is repeated on the 2-3rd day of illness. In adults, hyperemia and granularity of the mucous membrane of the soft palate, palatine arches, uvula are often detected, as well as hyperemia of the sclera. Signs of general intoxication are observed only in 10% of the total number of patients, they are weakly expressed.

All patients have abundant watery stools with a pungent odor, sometimes the feces are dull-whitish, they can resemble the feces of a patient with cholera. Loud rumbling in the abdomen is characteristic. The urge to defecate is of an imperative nature, there are no false urges. In some patients, there is an admixture of mucus and blood in the feces, which always indicates a combination of rotavirus disease with a bacterial infection (shigellosis, escherichiosis, campylobacteriosis). These patients have more pronounced fever and general intoxication. Signs of inflammation of the upper respiratory tract, which are detected in some patients with rotavirus diseases, are considered by some authors to be a consequence of the layering of a secondary viral infection.

With profuse loose stools, dehydration may develop. Dehydration develops quite often (in 75-85% of hospitalized children), however, in most cases (in 95%), it is expressed mildly (I and II degrees of dehydration according to V.I. Pokrovsky). Only in some cases does severe dehydration develop with decompensated metabolic acidosis. In these cases, acute renal failure and hemodynamic disorders are possible.

On palpation of the abdomen, there is pain in the epigastric and umbilical regions, a rough rumbling in the right iliac region. The liver and spleen are not enlarged. During sigmoidoscopy, most patients have no changes, only some patients have moderate hyperemia and edema of the mucous membrane of the rectum and sigmoid colon. Signs of damage to the digestive system persist for 2-6 days.

The amount of urine in the acute period of the disease is reduced, in some patients there is albuminuria, leukocytes and erythrocytes in the urine, an increase in the content of residual nitrogen in the blood serum. At the beginning of the disease, there may be leukocytosis, which is replaced by leukopenia during the peak period. ESR is not changed.

Complications
Rotavirus disease does not give complications. It is necessary to take into account the possibility of a secondary bacterial infection layering, which leads to changes in the clinical picture of the disease and requires a different therapeutic approach. The features of the course of rotavirus infection in persons with immunodeficiencies (HIV-infected, etc.) have not been sufficiently studied. Necrotizing enterocolitis and hemorrhagic gastroenteritis may occur.

Diagnostics of the Rotavirus Enteritis

Diagnosis and differential diagnosis
Recognition takes into account the clinical symptoms of the disease and the epidemiological prerequisites. Characterized by an acute onset, abundant watery stools without pathological impurities with a frequency of up to 10-15 times a day, vomiting, dehydration with a moderate temperature reaction and symptoms of general intoxication. The winter seasonality of the disease, the group nature, as well as the absence of positive findings during conventional bacteriological studies for the intestinal group of microbes are important.

The diagnosis is confirmed by the detection of rotaviruses in stool by various methods (immunofluorescent, etc.). Serological methods are of lesser importance (RSK, etc.). For the study of feces, a sterile wooden spatula is collected in a penicillin bottle (1/4 of the bottle), the rubber stopper is fixed with an adhesive plaster, and delivered to the laboratory in containers with ice.

Differentiate from cholera, dysentery, escherichiosis, gastrointestinal forms of salmonellosis, intestinal yersiniosis, protozoal diseases (giardiasis, cryptosporoidosis, balantidiasis).