respiratory syncytial virus pneumonia
Introduction
Introduction to respiratory syncytial virus pneumonia Respiratory syncytial virus pneumonia (respiratory syncytial virus pneumonia) is referred to as syncytial virus pneumonia, mainly caused by respiratory syncytial virus, the lesion mainly involves the bronchioles, clinical lower respiratory tract infection characterized by sudden onset of asthma and obstructive emphysema, Seen within 2 years old, especially in small infants within 6 months. The treatment of respiratory syncytial virus pneumonia is mainly symptomatic treatment and pathogenic treatment. If you have a bacterial infection, use antibiotics as soon as possible. basic knowledge The proportion of illness: 0.001% Susceptible people: more common within 2 years old, especially in small infants within 6 months. Mode of infection: non-infectious Complications: rhinitis laryngitis
Cause
Respiratory syncytial virus pneumonia
Respiratory syncytial virus (RSV, also known as syncytial virus, also belonging to Paramyxoviridae) is the most common cause of viral pneumonia in children, can cause interstitial pneumonia, and bronchiolitis, in Beijing, 48% of viral Pneumonia and 58% of bronchiolitis were caused by syncytial virus (1980-1984); in Guangzhou, 31.4% of children with pneumonia and bronchiolitis were caused by syncytial virus (1973-1986); in the United States, 20%-25 % of infant pneumonia and 50% to 75% of bronchiolitis are caused by syncytial virus. RSV is similar to parainfluenza virus under electron microscope. The virus particle size is about 150nm, which is slightly smaller than the parainfluenza virus. Sensitive to ether, no hemagglutination, formation of unique syncytium in human epithelial tissue, virus proliferation in cytoplasm, cytoplasmic inclusions, syncytial virus only one serotype, recent molecular biology The method proved to have two subtypes.
The incubation period of syncytial virus infection is 2-8 days (mostly 4-6 days). The typical manifestation of syncytial virus pneumonia is interstitial infiltration of monocytes, mainly manifested by alveolar septum widening and mononuclear cells. The interstitial exudation of the main, including lymphocytes, plasma cells and macrophages, in addition to the alveolar cavity filled with edema fluid, and the formation of a transparent membrane of the lung, in some cases, lymphocytic infiltration of the bronchiole wall, in the lung parenchyma There is edema associated with necrotic area, resulting in alveolar tamponade, consolidation and collapse. In a few cases, multinucleated fusion cells are seen in the alveolar space. The morphology is similar to measles giant cells, but no nuclear inclusions can be found. Gardner (1970) dissection A case of death virus of syncytial virus pneumonia, a large number of syncytial virus was detected by tissue fluorescent antibody test, no human globulin was found, and it was considered that pneumonia lesions may be mainly direct invasion of the lung by syncytial virus, not caused by allergic reaction. .
Prevention
Respiratory syncytial virus pneumonia prevention
Syncytial virus infection is extremely widespread, and the results of serum IgG resistance were measured by immunofluorescence in Beijing (1978): the cord blood positive rate was 93%, the birth rate was 89% in one month, and 40% in 1 to 6 months. Both aged and 3 years old are more than 70%, and from 4 years old to 14 years old, they are all about 80% positive (the complement binding assay is consistent with this). Since maternal antibodies cannot completely prevent the occurrence of infection, syncytial virus pneumonia is any after birth. Sometimes it can happen, more common in under 3 years old, 1 to 6 months can be seen in heavier cases, more men than women, more common in northern China in winter and spring, Guangdong is more common in spring and summer, due to antibodies can not completely prevent infection, syncytial virus Reinfection is extremely common. It has been observed for 10 years, and the incidence of reinfection is as high as 65%. The syncytial virus is highly contagious. It has been reported that family members have successive infections. When they occur in the family, older children and adults generally Respiratory infections, the literature reported that the rate of secondary syncytial virus infection in the hospital is as high as 30% to 50%.
The disease is generally mild, the simple case of clinical recovery from 6 to 10 days, X-ray shadow disappeared in 2 to 3 weeks, such as ineffective isolation, easy secondary infection, re-heating, simple syncytial virus pneumonia rarely died.
Complication
Respiratory syncytial virus pneumonia complications Complications rhinitis
May have rhinitis, pharyngitis, laryngitis, bronchiolitis and so on.
Symptom
Respiratory syncytial virus pneumonia symptoms Common symptoms Fever with chills, dyspnea, high fever, nasal congestion, fever, cough, slightly...
The disease is more common in infants and young children, more than half of them are infants less than 1 year old, male to female, the ratio is about 1.5 to 2:1, the incubation period is about 4 to 5 days, the initial cough, nasal blockage, about 2/3 Cases have high fever, up to 41 ° C, but fever is generally not sustainable, it is easier to fever by antipyretics, most of the hot time is 1 to 4 days, a few are 5 to 8 days, about 1/3 of the children are moderate Fever, more than 1 to 4 days, the heat history of most cases is 4 to 10 days, mild cases of dyspnea and neurological symptoms, moderate and severe dyspnea, wheezing, cyanosis, nose fan and Three concave signs, a small number of severe cases can also be complicated by heart failure, chest auscultation is mostly small or thick, middle Luoyin, percussion is generally no voiced, a few have had unvoiced.
Examine
Respiratory syncytial virus pneumonia
X-ray examination: Most of them have small flaky shadows, and large ones are extremely rare. About 1/3 of the sick children have different degrees of emphysema.
Blood: The total number of white blood cells is generally between (5 ~ 15) × 109 / L (5000 ~ 15000 / mm3), most of them below 10 × 109 / L (10000 / mm3), more than 70% of neutrophils.
Diagnosis
Diagnosis and diagnosis of respiratory syncytial virus pneumonia
diagnosis
In the past ten years, syncytial virus pneumonia and bronchiolitis accounted for the first place in infants and young children with viral pneumonia. The symptoms are almost indistinguishable from the parainfluenza pneumonia, mild influenza virus pneumonia and mild adenovirus pneumonia. Severe influenza virus Pneumonia and severe adenovirus pneumonia continue to have high fever, severe symptoms of poisoning and respiratory symptoms, and clinical manifestations are far more serious than syncytial virus pneumonia. The diagnosis of this disease is mainly based on the results of virology and serological examination. In recent years, the nasopharyngeal secretions have been exfoliated and Indirect immunofluorescence of serum IgM antibodies, ELISA, alkaline phosphatase anti-alkaline phosphatase bridging enzyme labeling (APAAP), biotin avidin ELISA, horseradish peroxidase - anti-horseradish Oxidase enzymatic method (PAP), monoclonal antibody fluorescence, etc. can all be used for rapid diagnosis of syncytial virus infection.
Differential diagnosis
It is distinguished from influenza, tropical pulmonary eosinophilic infiltration, persistent pulmonary eosinophilic infiltration, adenoviral pneumonia and other causes of pneumonia.
