Pediatric Ebola virus disease

Introduction to Ebola virus disease in children Ebola virus disease is an acute hemorrhagic infection caused by the Ebolavirus (EBOV) of filoviridae. It is mainly transmitted through the patient's blood and excretion. The main clinical manifestations are acute onset, fever, myalgia, hemorrhage, rash and liver and kidney dysfunction. May be complicated by myocarditis and pneumonia. There is no obvious seasonality in the onset, and the population is generally susceptible and there is no gender difference. At present, there is no specific treatment for Ebola virus disease, some antiviral drugs such as interferon and ribavirin are ineffective, mainly support and symptomatic treatment, including attention to water, electrolyte balance, control of bleeding; dialysis treatment in renal failure Wait. The treatment of patients with Ebola virus disease with plasma from convalescent patients is still controversial. The mortality rate of this disease is very high, up to 50% to 90%. basic knowledge The proportion of sickness: 0.0001% - 0.0002% Susceptible people: children Mode of infection: respiratory transmission Complications: hypotension, shock, orchitis, urethritis

The cause of Ebola virus disease in children

(1) Causes of the disease

The pathogen of this disease is Ebola virus, which belongs to the family of the linear virus (filoviviradae). It is a negative-strand RNA virus which is filamentous under an electron microscope. The virus was first discovered in 1976 and was first The location where the virus was detected, named after a river in Zaire, Africa, contains seven structural proteins, including RNA-dependent RNA polymerase, a single macromolecular glycoprotein, two nuclear proteins, one Matrix proteins, and a protein associated with the envelope, sequence analysis of the sixth gene of the viral genome showed that its gene arrangement is similar to that of baculovirus and paramyxovirus, and is very similar to Marburg virus. Although the Ebola virus is similar in morphology and structure to the Marburg virus of the same genus, there is no correlation in antigenicity and no cross-serosive response.

(two) pathogenesis

The virus enters the body through tiny skin mucosal damage, respiratory tract, and syringe injection. It initially enters the mononuclear macrophage system, and other endothelial cells, fibroblasts, adrenal cortex, intercellular spaces, blood vessels and interstitial spaces grow and reproduce. Enter the blood circulation, form viremia, and then enter a wide range of tissues and organs, such as liver, kidney, lymphoid tissue, ovary, testis, skin, etc., early damage to lymphoid tissue, a huge impact on the immune system, the virus damages vascular endothelial cells, The ability of endothelial cells to produce prostacylin is impaired, platelet aggregation is increased, platelet activating factor (PAF) is elevated, endothelial cell damage activates coagulation mechanism, DIC, microcirculatory disorder and tissue ischemic necrosis occur in infection Intravascular fibrin deposition, thrombocytopenia and hemorrhage, except for muscle and bone, focal necrosis can be seen in all organs and tissues, diffuse microscopic hemorrhage, especially liver, kidney, lung, pancreas and lymphoid tissue. Viral particles and eosinophilic inclusion bodies are widely observed in tissues, microcirculation system Bad, there are a lot of lymphocytes, but no obvious inflammatory reaction, due to DIC, hemorrhage and plasma exudation, decreased circulating blood volume, hypotension, shock, electrolyte and acid-base balance disorders, central nervous system DIC causes local bleeding , edema, coma, convulsions, severe death.

Pediatric Ebola virus disease prevention

It is still controversial to present protective neutralizing antibodies to individuals who are able to induce Ebola virus infection. Prevention is mainly to isolate patients, and the patient's secretions, excretions and used items should be thoroughly disinfected, and medical personnel must strictly implement protective measures. Ebola virus may have new, more toxic variants due to natural selection, and may cause global pandemics through aerosol transmission. Therefore, the natural host of the virus should be determined as soon as possible, and rapid diagnostic methods and vaccines should be established. Prevention and control of this disease is of great significance.

In order to obtain high titer antiviral immune serum, it has been obtained from animals such as sheep, goats and the like which are not sensitive to Ebola virus, and has an protective effect on animals.

Pediatric Ebola virus disease complications Complications hypotension shock orchitis urethritis

Can occur DIC, skin, gastrointestinal tract can be bleeding, can occur hypotension, shock, electrolyte and acid-base balance disorders, due to multiple focal local necrosis, can be complicated by pancreatitis, orchitis, urethritis, mumps, Glossitis, pneumonia, cleft lip, oral ulcers, etc.

Symptoms of Ebola virus disease in children Common symptoms Severe headache Abdominal pain, rash, chills, fatigue, muscle pain, loss of appetite, diarrhea, sore throat

Ebola virus disease is a disease of multiple organ damage, mainly affecting the liver, spleen and kidney. The incubation period is 3 to 18 days. The main clinical manifestations are the onset of fever. There are fever, severe headache, sore muscles and joints, and sometimes abdominal pain. It can cause nausea, vomiting, abdominal pain, diarrhea, mucus or bloody stools, and diarrhea can last for 2 to 3 days. day. The course of disease enters the extreme period from 4 to 5 days, and the fever continues, and there is a change in consciousness, such as paralysis and lethargy. This period of bleeding is common, may have hematemesis, melena, bleeding at the injection site, nose bleeding, hemoptysis, etc., pregnant women have abortion and postpartum hemorrhage. During the course of 6 to 7 days, measles-like rash can appear on the trunk and spread to all parts of the body. After a few days, the person will have desquamation, which is more common in the shoulders, palms and soles. Severe patients often die from bleeding, liver, kidney failure or serious complications on the 8th to 9th day of the disease. Non-severe patients gradually recovered 2 weeks after onset. Most patients developed asymmetric joint pain, which may be migratory, mainly involving large joints. Some patients have myalgia, fatigue, suppurative mumps, hearing loss or Delayed damage such as tinnitus, conjunctivitis, monocular blindness, uveitis, etc. In addition, due to the persistence of the virus in the semen, causing orchitis, testicular atrophy and the like. Acute complications include myocarditis and pneumonia.

Some people with asymptomatic infections in the EHF outbreak have EBOV IgG in their serum. Asymptomatic infections have little epidemiological significance, their virus levels are low, and they are cleared by the body's effective immune response in a short period of time. It can disappear quickly within 2 to 3 days, thus avoiding heat and tissue damage.

Pediatric Ebola virus disease examination

1, blood routine examination

Early white blood cells were slightly reduced, and then rose back to (0.9 ~ 1.2) × 109 / L, thrombocytopenia after DIC.

2, urine routine examination

Proteinuria is seen early.

3, blood biochemical examination

Blood AST, and ALT increased, the disease is characterized by AST significantly higher than ALT, amylase increased, a small number of human serum albumin decreased.

4, cerebrospinal fluid examination

Generally normal.

5, virus electron microscopy

The detection of viral particles by electron microscopy from the patient's blood, urine, skin containing sweat glands, and liver puncture tissue is a direct and rapid diagnostic method for Ebola hemorrhagic fever.

6, virus isolation and culture

The blood, urine, secretion or autopsy tissue suspension of the acute phase patient was inoculated into Vero cells, and the intracellular virus was detected by indirect immunofluorescence staining on the third day. The above materials were also inoculated into guinea pigs or monkeys to observe the incidence. And use indirect immunofluorescence to measure blood and tissue viruses.

7, virus antigen detection

The ELISA method can be used to quickly and easily detect the blood of the patient and secrete the viral antigen in the excretion. 10 ng of viral protein can be detected by direct solid phase enzyme immunoassay, (5-50)×103 PFU/ml virus, with monoclonal The antibody sandwich enzyme immunoassay was used to detect the virus in the tissue samples, and the positive rate was 92.7%. The spot immunoassay (DIA) method was used to detect the serum of the patient, and the virus could also be detected.

8, virus antibody detection

Neutralization test or complement fixation test can detect virus neutralizing antibodies in blood, and detect the virus-specific IgM and IgG in blood by indirect immunofluorescence method and ELISA method. The positive rate of indirect immunofluorescence method is 83.3%94.4%. IgM antibody appears early and peaks at 1 week after onset. It can be used as a basis for early diagnosis. After 1 month, IgM decreases, and specific IgG antibody rises. For example, the IgG antibody in the patient's double serum is increased by more than 4 times. Can be diagnosed.

9, molecular biology testing

Ebola hemorrhagic fever virus can be detected by RT-PCR technology with high sensitivity.

Diagnostic identification of pediatric Ebola virus disease

diagnosis

The clinical manifestations of this disease are similar to those of other viral hemorrhagic fever. The diagnosis is determined by pathogenic or serological diagnosis. The Ebola virus antigen is detected by laboratory methods from the blood of patients or suspected infected persons or other clinical specimens. The virus can be diagnosed by separating the virus with the antibody or nucleic acid or by virus isolation method. However, because the disease is highly contagious, the laboratory for diagnostic testing must have corresponding measures for strict protective facilities. The laboratory currently used in the African affected areas. The detection methods include ELISA and Western blotting tests for detecting specific IgM and IgG antibodies, and some are also used to detect RNA of the virus by reverse transcription PCR. Saijo et al. recently reported the use of genetically engineered Ebola virus core protein carboxyl group. The peptides of segment 110 and 102 amino acids are antigens, and an ELISA method for detecting Ebola virus IgG antibody has been developed, which has high specificity and sensitivity, and has strong diagnostic significance for Ebola virus and Marburg virus infection. .

Differential diagnosis

According to the characteristics of regional distribution of epidemiology, clinical manifestations, positive results of laboratory tests for diagnosis, in the differential diagnosis must be associated with African hemorrhagic diseases such as Marburg disease, Rift Valley fever, Lassa fever, Crimea - The difference between Congo haemorrhagic fever and yellow fever is mainly based on pathogen detection.

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