Rotavirus enteritis
Introduction
Introduction to rotavirus enteritis Rotavirus gastroenteritis is an acute digestive tract infection caused by rotavirus, also known as autumn diarrhea. Pathogens are mainly transmitted through the digestive tract. The main clinical manifestations are acute fever, vomiting and diarrhea, and the course of disease is mostly short. It is one of the most common causes of diarrhea. It can occur in epidemics or pandemics. This disease mainly occurs in infants and young children. It is often caused by group A rotavirus. The peak incidence is in autumn, hence the name infant autumn diarrhea. About 125 million diarrhea in infants and young children worldwide are caused by rotavirus infection each year, most of which occur in developing countries. Group B rotavirus can cause diarrhea in adults. basic knowledge The proportion of illness: 10% Susceptible people: good for infants and young children Mode of infection: digestive tract spread Complications: Intussusception Allergic purpura Hemolytic uremic syndrome Diffuse intravascular coagulation
Cause
Cause of rotavirus enteritis
Virus infection (45%):
Whether rotavirus can cause disease after entering the body depends on the number of infected viruses. The amount of invading virus is large, which helps the virus to invade. When rotavirus enters the body, it causes diarrhea through two ways: First, rotavirus directly on the small intestine villi Epithelial cell damage, causing pathological changes; Second, the metabolites of rotavirus in the process of replication act on small intestinal endothelial cells, destroying the normal physiological function of intestinal cells and causing diarrhea. A small amount of virus will be immune to the body's own immunity and will not develop disease.
Physiological factors (10%):
The physiological characteristics of the body itself can cause the disease to occur. When the lactose enzyme (which is a rotavirus receptor) in the brush border of the intestinal epithelium of the body is high, such as in infants, it is easy to infect rotavirus. As the age increases, the amount of this enzyme decreases and the susceptibility decreases.
Low immunity (10%):
When various factors cause decreased immunity, it helps rotavirus invade and induce disease.
Pathogenesis
When the rotavirus invades the human body and reaches the small intestine, it enters the epithelial cells through its coat protein Vp4 (adsorbed protein) and lactase on the intestinal mucosal epithelial cells, which proliferates and destroys in the epithelial cytoplasm, and falls off due to the villus epithelium. The cells are destroyed, the disaccharases such as lactase are reduced, and the conversion of lactose to other monosaccharides is blocked. The accumulation of lactose in the intestinal lumen causes high osmotic pressure in the small intestine and colon, which causes water to migrate into the intestinal lumen, leading to diarrhea and vomiting. The cubic epithelial cells from the bottom of the crypt are moved up to replace the exfoliated villus epithelial cells. Due to their immature cell function, they are still in a high secretion and low absorption state, resulting in retention of intestinal fluid, prolonging diarrhea, and rotavirus replication. The non-structural protein NSP4 synthesized in the process, which plays a role in enterotoxin during the pathogenesis of rotavirus, can cause the increase of intracellular Ca2 level, promote the increase of cAMP level in small intestinal mucosa and participate in the formation of diarrhea, such as diarrhea and vomiting. Can cause water, electrolyte imbalance and acidosis.
The disease is a reversible pathological change, the mucosa often maintains integrity, and the main damaged part is in the small intestine. The biopsy shows that the small intestine villi are shortened and blunt, the lamina propria mononuclear cells infiltrate, the epithelial cells are irregular, cuboidal, with vacuoles or necrosis. .
Prevention
Rotavirus enteritis prevention
Cutting off the route of transmission is the focus of prevention.
1. Management of infectious sources: patients should be detected early and patients should be isolated, and close contacts and suspected patients should be closely observed.
2. Cut off the route of transmission: strengthen diet, drinking water and personal hygiene, do a good job of disinfection of patients' feces: prevent drinking water sources and food from being contaminated, hospitals must strictly do disinfection of baby areas and newborn rooms, such as stool can not be controlled Children should be restricted from entering day care or school.
3. Vaccination: The rotavirus vaccine can be used in clinical practice. During the epidemic period, the passive immunization method for high-risk groups and susceptible people also has a certain preventive effect. Human milk can have a protective effect to a certain extent. Breastfeeding is advocated to reduce the severity of illness in young children. The milk of calves immunized with bovine rotavirus contains IgA and IgG antibodies. Feeding infants with this milk also has a protective effect.
Complication
Rotavirus enteritis complications Complications, intussusception, allergic purpura, hemolytic uremic syndrome, disseminated intravascular coagulation
A small number of complicated intussusception, gastrointestinal bleeding, allergic purpura, Reye syndrome, encephalitis, hemolytic uremic syndrome, DIC (diffuse intravascular coagulation), elevated ALT (alanine transaminase).
Symptom
Rotavirus inflammatory symptoms common symptoms fatigue watery stool diarrhea nausea abdominal tenderness abdominal pain bowel bloating low fever
1. The incubation period of infants and young children is 24-72h, the onset is more urgent, vomiting is often the first symptom, accompanied by diarrhea several times a day, mostly for a lot of watery stools, yellow-green, stench, can have a small amount of mucus, no Pus and blood, can be pseudo-cholera diarrhea, patients with low fever, rarely more than 38 ° C, most of the early stage of the disease with runny, sneezing and light cough, more than half of the children have varying degrees of dehydration and acidosis, can be serious Dehydration, the condition deteriorates and dies within a few hours, generally fever, vomiting subsides within 48h, and diarrhea can last for more than 1 week. If the condition is severe, it is intolerant to carbohydrates, and it usually takes several weeks to six months to recover.
Newborns can also develop disease, diarrhea is lighter, may have abdominal distension and bloody stools, X-ray examination can be seen abnormal intestinal type, and even intestinal perforation can occur.
2. The incubation period of adult patients is the shortest hours, the longest is up to 1 week, the average is 2 to 3 days. The disease is more acute, with abdominal pain and diarrhea, fatigue, nausea and vomiting, etc. The stool is mostly yellow watery stool. No mucus and pus and blood, diarrhea usually varies from 5 to 9 times or more than 10 times a day. In severe cases, it can reach more than 20 times a day. The bowel sounds are enhanced, the abdominal tenderness is obvious in the umbilical cord, and some patients have varying degrees of dehydration. Most patients have normal body temperature, a few patients have low fever, and the course of disease is short, generally 3 to 5 days, mostly self-limited, and a few can reach more than 9 days.
Examine
Inspection of rotavirus enteritis
1. Routine examination: blood routine: the total number of white blood cells is mostly normal, a few slightly increased, lymphocyte increase in cell classification, stool examination: the appearance of yellow watery stool, no mucus pus and blood, no abnormalities in microscopic examination.
2. Detection of virus and viral antigen in feces: Detection of virus in feces by electron microscopy: electron microscopy makes a specific diagnosis by observation of typical morphology, and its positive rate can reach 90%. This method is fast and accurate, but the equipment is expensive and the operation requirements are high. Therefore, it is mostly used for epidemiological investigations. Detection of virus-specific antigens: Many immunological methods can be used to detect rotavirus-specific antigens, such as enzyme immunoassay (EIA), complement binding assay (CF), immunofluorescence (IF) methods, etc., where EIA is specific, High sensitivity and easy operation.
3. Detection of viral nucleic acid in feces: Polyacrylamide gel electrophoresis, nucleic acid hybridization and polymerase chain reaction (PCR) methods can be applied. The nucleic acid hybridization method has high specificity, and the PCR method has high sensitivity and is mostly used for Molecular epidemiology research.
4. Serum antibody detection of rotavirus: The specific antibody in the serum of patients is detected by immunological methods such as EIA. For example, the antibody titer of the double serum in the acute phase and the recovery phase is increased by 4 times, which is diagnostic.
Diagnosis
Diagnosis and diagnosis of rotavirus enteritis
diagnosis
The diagnosis is based mainly on epidemiological data and clinical manifestations.
1. Epidemiological data: According to the epidemic season, patients with similar intestinal symptoms in the epidemic areas should pay attention to this disease.
2. Clinical manifestations: the incubation period is shorter, the onset is more urgent, the manifestation is diarrhea, yellow watery stool, and some children may be associated with respiratory symptoms.
Differential diagnosis
1. Bacterial intestinal infections occur mostly in summer and autumn, and the body temperature rises more than 39°C. Abdominal pain and diarrhea are obvious. After starting to be loose for 2 to 3 times, it turns into mucopurulent stool, or mucus pus and blood. There are urgency and heavy weight, left lower abdomen tenderness, blood white blood cells rise, stool microscopic examination has a lot of red, white blood cells, stool culture can detect dysentery bacilli, Campylobacter jejuni.
2. Identification with Nowalk virus, intestinal adenovirus and other infections: clinical manifestations and general laboratory tests are basically the same, relying on multivalent antibody immunoelectron microscopy, viral nucleic acid electrophoresis, ELISA detection of antigen antibodies to identify.
