Neonatal coxsackievirus B infection
Introduction
Introduction to neonatal coxsackievirus B infection Coxsackievirus B (CVB) infection has been reported since the 1954 report in Coxsack, New York, USA. In addition to causing neonatal sporadic infections, it has been repeatedly epidemic in some parts of the world, mainly invading immunity. Inferior neonates and areas with poor sanitation, clinically characterized by myocardial, brain and many other organ inflammatory lesions, the serious outbreak of this disease, its mortality rate was as high as 26% to 69.4%, which is more harmful to newborns Has attracted the attention of neonatal scholars worldwide. In recent years, China, Beijing, Huangshan, Shenyang and other regions have also experienced different scales of popularity in the baby room. basic knowledge Sickness ratio: 0.0012% Susceptible people: children Mode of infection: digestive tract spread Complications: shock jaundice
Cause
Causes of neonatal coxsackievirus B infection
(1) Causes of the disease
Coxsackie virus belongs to the class of RNA virus (Gate), small RNA virus family, and enterovirus group. It is relatively stable at room temperature. When the ambient temperature is increased to 50 °C, it only survives for 1 hour. The virus is more resistant to acidic environment. It is not sensitive to antibiotics and chemical drugs, but sensitive to oxidants. It is easily killed by 1% potassium permanganate, 1% hydrogen peroxide or chlorine-containing oxidant. According to the damage characteristics of organs, Coxsack virus is divided into A. In group B, group A mainly caused neurological, muscular and systemic infections, aseptic meningitis, paralytic diseases, upper respiratory tract infections, herpes angina, etc. Group B mainly invaded the heart, brain, liver and other Organs, causing myocarditis, pericarditis, viral encephalitis, etc., coxsackievirus group B using neutralization test and complement binding assay to determine antigen can be divided into 6 types (CVB1 ~ 6), according to recent reports to CVB3, CVB5 type Infection is the most harmful to newborns and the highest incidence.
(two) pathogenesis
It has been confirmed that in addition to causing cardiac damage, neonatal CVB epidemic infection can cause multiple organ damage. The pathological changes are infiltrated by affected tissue inflammatory cells, tissue cell degeneration, and focal necrosis is more common.
1. Heart: Myocarditis is the main change, myocardial congestion, edema, necrosis and inflammatory exudation, lymphocytes, monocytes, reticulocytes, plasma cells and polymorphonuclear cells infiltrate, and spread to the endocardium, Pericardium, edema and inflammatory cell reactions, and part of the heart cavity enlargement.
2. Brain: It is a change of viral meningitis and meningoencephalitis. The main pathological changes are as follows:
(1) meningeal congestion, edema and inflammatory cellular responses.
(2) The brain and spinal cord showed focal lesions. The cortical cells in the lesion showed eosinophilic degeneration. Monocytes and glial cells infiltrated, especially the leukocyte aggregation around the blood vessels.
3. Lung: changes in focal pneumonia:
1 Infiltration of mononuclear cells around the bronchi.
2 There is bleeding change in the alveoli.
3 capillary bronchiectasis.
4 a few cases of pulmonary bullae.
4. Other organs
1 liver enlargement, focal necrosis and mononuclear cell infiltration.
2 renal medullary necrosis, tubular edema and calcium salt deposition.
3 adrenal cortical necrosis, hyperemia and inflammatory cell infiltration.
4 islet cells have focal degeneration.
5 bone marrow showed an inflammatory reaction: the granular red system was active, and the tissue cells proliferated, but the megakaryocytes were significantly inhibited.
Prevention
Neonatal coxsackievirus B infection prevention
Strengthen the health care work during pregnancy, actively prevent and treat various infectious diseases, prevention should be carried out from pre-pregnancy to prenatal:
The pre-marital medical examination items and contents mainly include serological examination (such as hepatitis B virus, treponema pallidum, HIV), reproductive system examination (such as screening for cervical inflammation), general physical examination (such as blood pressure, electrocardiogram), and asking about the family history of the disease. Medical history, etc.
Pregnant women should avoid harmful factors as far as possible, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals, etc. In the process of antenatal care during pregnancy, systematic screening of birth defects is required, including Regular ultrasound examination, serological screening, etc., if necessary, also carry out chromosome examinations, and do a good job in genetic disease consultation.
Once an abnormal result occurs, it is necessary to determine whether to terminate the pregnancy; the safety of the fetus in the uterus; whether there is sequelae after birth, whether it can be treated, how to prognose, etc., and take practical measures for diagnosis and treatment.
Complication
Neonatal coxsackievirus B infection complications Complications shock jaundice
There may be shock, jaundice, liver and spleen, heart failure, respiratory failure, acute renal failure and other multiple organ failure (MOF), to sudden death, arrhythmia, convulsions, coma and liver damage, also known as the brain - Liver-myocarditis, bleeding tendency can occur, and even changes such as DIC and pulmonary hemorrhage occur.
Symptom
Newborn coxsackievirus B infection symptoms common symptoms pale pale hairy bloating gastrointestinal symptoms before sputum tension increased diarrhea nausea convulsions dyspnea jaundice
The incubation period of neonatal Coxsackie virus infection can be very different. Generally, 7 to 14 days after birth, the intrauterine vertical infection is more common within 5 days after birth. After infection, the infection occurs after 5 days, and the incubation period is long. Also related to different serotypes, neonatal individual factors (gestational age, age, immune status, etc.), mild neonatal CVB infection can have no obvious clinical manifestations, while severe cases can invade multiple organ systems, even death, CVB difference Serotype infections can have similar clinical manifestations, and the clinical manifestations of different individuals infected with the same serotype are also very different.
1. Fever and sepsis-like manifestations: Most children have a sharp onset, fever, body temperature is above 38 °C, the heat type is irregular, and it gradually recovers after several days or even more than 10 days. It can be accompanied by irritability during fever. Less, vomiting, diarrhea and other nerves, digestive system symptoms, with the recovery of body temperature, most of the self-healing, moderate, severe cases with acute sepsis-like systemic manifestations, 1 to 2 days after the onset of shock, jaundice, liver spleen Difficulty breathing, convulsions, even DIC, pulmonary hemorrhage, heart failure, respiratory failure, and sudden death.
2. Cardiovascular system performance: This type of infection is mostly CVB24 infection, mainly showing severe myocardial damage. This type is usually 5 to 9 days after birth. It can have fever, wilting, diarrhea, refusal, and after a few days. Signs of myocarditis, tachycardia, heart enlargement, galloping, pale, difficulty breathing, decreased blood pressure and other heart failure or cardiogenic shock, ECG showed low voltage, T wave low or inverted, PR interval prolonged And a variety of arrhythmia, ultrasound examination can have a wide range of myocardial damage, such as rapid progression of the disease, can be life-threatening, some cases have convulsions, coma and liver damage, also known as brain-liver-myocarditis, this type of condition is critical.
3. Multiple organ system function damage: In the case of neonatal CVB outbreak epidemic infection, severe cases are often accompanied by multiple organ damage in the heart, brain, lung, liver, kidney, and blood systems, and even multiple organ failure (MOF) In addition to coma, convulsions, central nervous system damage, there may be increased anterior tendon tension, muscle tension changes, abnormal reflection, cerebrospinal fluid protein increase, sugar, chloride normal, the number of cells is generally below 500/mm3, most of the data reported nerve Systemic damage is mostly restored in 7 to 10 days. Digestive system damage is characterized by gastrointestinal symptoms and liver damage. It may have abdominal distension, nausea, vomiting, hepatosplenomegaly, liver function disorders, alanine aminotransferase (ALT), jaundice. Kidney damage manifests as oliguria, no urine, edema, hematuria, proteinuria, azotemia and other acute renal failure manifestations. Lung damage is mainly pneumonia and pulmonary hemorrhage. Clinically, there may be difficulty breathing, cyanosis, and intrapulmonary voice. Chest radiographs showed enhanced lung texture, patchy shadows, blood system damage including bleeding tendency, skin bleeding spots, ecchymosis, and decreased platelet count and DIC changes.
Examine
Examination of neonatal coxsackievirus B infection
Laboratory examination is the main basis for the early diagnosis and diagnosis of the disease, including virus isolation and detection of serological specific antibodies.
1. Virus isolation: CVB should be isolated and cultured early to improve the positive detection rate of pathogens. The specimens can be selected from children's secretions (throat swabs, rectal swabs, stools, etc.), blood, cerebrospinal fluid and tissue cells. Subculture with Hela cells and human embryonic lung fibroblasts until the lesions of the cells appear to be positive, but it should be emphasized:
(1) The virus must be isolated from the body fluid (blood, cerebrospinal fluid, pericardial fluid, etc.) or in the autopsy tissue of the child.
(2) Some typical syndromes (such as meningitis, myocarditis, etc.) appear in the clinic. It is diagnostic value to repeatedly isolate the same serotype virus from throat swabs and feces.
2. Serological detection: The main application methods of CVB serological examination are neutralization test and indirect immunofluorescence technique. The neutralization test is a detection method in which the virus is neutralized by specific antibodies in vivo or cell culture. To check the growth of antibodies in the serum of children or to check the antibody level after latent infection in the population, the specificity of neutralizing antibodies is higher, the maintenance time is longer, suitable for epidemiological investigation, clinically more indirect immunofluorescence test, immunofluorescence The technology can directly detect viral antigens, and can also use its indirect immunofluorescence assay to determine CVB antibodies, ie specific IgM, which is a clinically effective and rapid serological diagnostic method for the present disease.
3. PCR detection and dot blot hybridization: Since 1980, foreign scholars have applied molecular virology techniques to the diagnosis of viral pathogens, and nucleic acid hybridization methods have been used to detect enterovirus DNA and RNA in serum and myocardial specimens. It has high specificity and rapid characteristics and is suitable for clinical applications.
4. Bone marrow examination: There may be granules, erythroid hyperplasia is active, giant system is suppressed, and a small number of patients with severe erythrocytosis are low.
5. Electrocardiogram examination: display low voltage, T wave low or inverted, prolonged PR interval and various arrhythmia.
6. Ultrasound examination: There may be extensive myocardial damage.
7. X-ray examination: The chest radiograph shows enhanced lung texture and patchy shadows.
Diagnosis
Diagnosis and identification of neonatal coxsackievirus B infection
Clinical diagnosis should be analyzed from the clinical characteristics and epidemiological data of the patients.
1. Clinical characteristics of infants: perinatal neonatal morbidity, unexplained fever; upper respiratory tract infection or sepsis-like manifestations, combined with myocardial damage; clinical manifestations of infection, but the disease progresses rapidly, the condition is critical, does not support bacteria Infected.
2. Epidemiological data: concentrated episodes of neonates, summer and autumn; mother or infant room medical staff recently had a history of fever and other infections, similar to upper respiratory tract infections in the baby room, children with fever at the same time or successive onset.
The above clinical features can be confirmed in combination with laboratory tests and auxiliary tests.
It is differentiated from sepsis and differentiated from TORCH syndrome.
