OVERVIEW
Respiratory syncytial virus infection is a disease characterized by respiratory lesions caused by respiratory syncytial virus. Respiratory syncytial virus infection can occur throughout the year, but is more common in winter and spring, and is slightly more common in men than in women. The disease is clinically characterized by coughing, wheezing, dyspnea and, in severe cases, heart failure. The virus can survive for several hours on the surfaces of various objects as well as on the surfaces of unwashed hands, and the infection is acquired through direct contact with virus-contaminated objects or through direct contact or inhalation of aerosols.
Etiology
The disease is caused by infection with respiratory syncytial virus.
Symptoms
1. Epidemiology
It occurs mainly in infants within the first year of life and is more common in male infants. Elderly and immunocompromised people may also develop the disease. The incubation period is 3-7 days, and the disease usually develops in winter and spring.
2. Systemic symptoms
The clinical manifestations of this disease are varied, most of them are symptoms of upper respiratory tract infection, and about 25% to 40% of infants show symptoms of bronchitis, capillary bronchitis, asthma, pneumonia and so on. Generally, the disease often starts with upper respiratory symptoms such as low-grade fever, runny nose and loss of appetite, followed by cough, often accompanied by wheezing, moderate shortness of breath, increased nasal discharge and intermittent fever. Infection with respiratory syncytial virus in preterm infants and those of younger months of age may present as episodes of apnea with no obvious respiratory symptoms. The lungs may have diffuse fine rales and rales.
3. Skin symptoms
A small number of children with respiratory syncytial virus infection may have simple erythema of the face and trunk.
4. Other
In adults, respiratory syncytial virus infection presents as a common upper respiratory tract infection. In the elderly, it may cause febrile bronchitis and pneumonia.
Examination
1. Auscultation
Diffuse rales and rales may be present in the lungs.
2. Laboratory tests
(1) The total number of white blood cells is normal or slightly decreased, the number of lymphocytes is relatively increased, and the blood sedimentation is normal or increased.
(2) Nasal washings, nasopharyngeal swabs, blood, and sputum from the patient can be used for chick embryo culture, animal inoculation, or cell culture to isolate the virus.
(3) Respiratory syncytial virus antigen can be detected in patients’ respiratory secretions by immunofluorescence method, which has diagnostic value.
3. X-ray examination
X-ray chest radiographs show point or sheet shadows in both lungs, and about one-third of the cases have different degrees of emphysema. About one third of the cases have different degrees of pulmonary emphysema. In capillary bronchitis, there are different degrees of obstructive pulmonary emphysema in the whole lung, and there are images of peribronchiolitis or thickening of pulmonary texture, and some cases involve alveoli and see small dots and flaky shadows.
Diagnosis
Typical respiratory symptoms such as coughing and wheezing, a specific season of high incidence, and a high prevalence of infants and children are the main references for clinical diagnosis.
The diagnosis is based on the observation of chest X-rays, immunofluorescence, isolation of the virus, epidemiologic history and laboratory tests.
Treatment
1. Supportive treatment
Symptomatic and supportive treatment is extremely important. For those with respiratory distress, attention should be paid to blood gas analysis, asthma control and oxygen absorption.
2.Drug treatment
Immunoglobulin: in severe cases, immunoglobulin can be injected intravenously.
Prevention
1. Disinfect pollutants and hands, isolate patients. Attention to avoiding crowd gathering and close contact with infected persons, etc. during epidemics can help reduce the rate of respiratory syncytial virus infection.
2. Palizumab is the only prophylactic drug available for respiratory syncytial virus infection, but it is very expensive.