Pediatric viral hepatitis E
Introduction
Introduction to Pediatric Hepatitis E Hepatitis E (HE) is an infectious disease caused by hepatitis E virus (HEV), which is transmitted from the faecal tract and is mainly caused by liver damage. It can often cause epidemics and outbreaks, and its clinical and epidemiological characteristics are similar to those of hepatitis A. basic knowledge The proportion of illness: 0.0017% Susceptible people: children Mode of transmission: mother-to-child transmission of digestive tract Complications: chronic hepatitis, hepatic encephalopathy, hepatorenal syndrome, peritonitis
Cause
The cause of viral hepatitis in children
(1) Causes of the disease
Hepatitis E virus (hepatitis E viras, HEV) belongs to the family of Inxoviridae, without envelope, and the nucleic acid is single-stranded positive-stranded RNA. There are two genotypes: Burmese strain (B) and Mexican strain (M). The former is of the same subtype, the virus is unstable in vitro, sensitive to high salt, barium chloride, chloroform, etc., cell culture has not been established, and a variety of non-human primates can infect HEV.
(two) pathogenesis
HEV mainly invades the liver, causing hepatocyte inflammation and necrosis through direct pathogenic effects and/or immune damage. Liver pathological changes include hepatocyte degeneration, focal necrosis, lymphocytes in the portal area, mononuclear macrophages and NK cell infiltration. More than half of patients with acute jaundice can be seen with cholestatic and gallbladder thrombosis.
Prevention
Pediatric hepatitis E prevention
Because the patient has a large amount of detoxification before the onset of symptoms in the late stage of the incubation period, it is contagious, it is difficult to find and take isolation measures in time, and there is no active or passive immune preparation for prevention. Therefore, the prevention strategy for hepatitis E is to cut off Comprehensive prevention measures based on transmission routes.
Most epidemics of hepatitis E are transmitted by water, ensuring safe drinking water, widely publicizing drinking water, not drinking raw water, improving environmental hygiene and personal hygiene, vigorously carrying out health education, managing water sources, feces, food and patients, and actively To carry out the patriotic health campaign, we should pay special attention to collective units and child care institutions to prevent epidemics and reduce the number of cases.
Existing gamma globulin can not prevent this disease, HEV gene recombinant vaccine is still under development, using HEV gene polypeptide, containing ORF3HEV cDNA fragment, inserted into eukaryotic expression plasmid (pSVL), construct HEV cDNA vaccine, inoculate experimental mice, The serum of rats can be positive for anti-HEV, which provides feasibility for the development of HEV gene vaccine, mainly to protect water source, strengthen food hygiene management, pay attention to personal hygiene and improve environmental sanitation. Human gamma globulin has no obvious preventive effect on this disease. Genetic recombinant vaccines and nucleic acid vaccines are under investigation.
Complication
Pediatric hepatitis E complications Complications chronic hepatitis hepatic encephalopathy hepatorenal syndrome peritonitis
A small number may be acute or subacute severe hepatitis, or chronic hepatitis, severe complications such as hepatic encephalopathy, liver and kidney syndrome, secondary infection, bleeding, electrolyte imbalance, primary peritonitis.
Symptom
Children with hepatitis E virus symptoms Common symptoms Upper abdominal discomfort Skin yellowing Loss of appetite Liver pain Sclera Yellow stained Huangqi Liver splenomegaly nausea and vomiting Joint pain Skin itching
The incubation period is 10 to 60 days, with an average of 40 days. The clinical manifestations are similar to those of hepatitis A. They do not develop chronically. Children are mostly subclinical infections. Common clinical types are:
1. Acute jaundice type: 86.5% of dominant infections, clinical stage III experience with hepatitis A, prodromal symptoms can last until the 4th to 5th day after the appearance of jaundice, cholestatic is more common, the total course of disease is 4 to 6 weeks.
2. Acute jaundice-free: The performance is similar to that of hepatitis A.
3. Cholestatic: More common, the course of disease can be as long as 2 months or more.
4. Heavy: About 5%, high risk factors include:
1 pregnant woman;
2 years old and infirm;
3 combined with HBV infection, mostly acute heavy.
5. Mixed infection with other viruses
(1) HEV and HAV infection at the same time or in succession: does not aggravate the condition.
(2) HEV and HBV overlap infection: patients with HBV often have active replication, HEV is not easy to be removed, the disease is prone to prolonged or recurrent, the condition is heavy, and there are many serious cases. India reported 80.7% of acute heavy and 75.5% of Asian Acute heaviness is caused by overlapping HEV infections in HBsAg carriers.
Examine
Examination of pediatric hepatitis E virus
1. Detection of viral particles and antigen: The virus particles are detected by immunoelectron microscopy at the end of the latent period to the acute early stage, or the viral antigen is detected by enzyme immunoassay. The detection rate of the patient is 100% before 1-4 days before the disease. ~3 days to 70%, 4 to 6 days 60%, 7 to 9 days 25%, can not be detected after 2 weeks, the latter is prone to false positives.
2. Serological examination: The acute phase-specific IgM positive has clinical diagnostic value. After 2 to 3 weeks after onset, the specific IgG detection rate is 72.7%, and 84.9% at 4 to 8 weeks. The complete ORF2 protein is used as antigen. The established EIA method has high sensitivity and specificity.
3. Viral gene examination: HEV RNA can be detected in serum and feces by RT-PCR. Should do abdominal B ultrasound to understand the liver, spleen and so on.
Diagnosis
Diagnosis and diagnosis of viral hepatitis E in children
The disease is not difficult to diagnose according to epidemiological data, typical clinical features and specific serological tests, but before the onset of jaundice or without jaundice, especially fever, respiratory symptoms or gastrointestinal symptoms, it is easy to be misdiagnosed as Respiratory tract infections, gastritis, diarrhea, etc., should be noted for identification; such as fever, jaundice and abdominal pain need to be differentiated from biliary ascariasis and biliary tract inflammation; cholestatic hepatitis should be differentiated from choledochal cyst and cholelithiasis.
