Respiratory syncytial virus infection

　　The disease is caused by respiratory syncytial virus or fusion virus (RSV). It belongs to the paramyxovirus RNA type, with a diameter of 100 to 140 nm, and the nucleocapsid is composed of 32 symmetric icosahedral capsids. It has a envelope. It is not destroyed by ether or chloroform. The virus can be cultured in human cells, diploid cells, and primary monkey kidney cells, and can produce special fusion cells, hence the name. The virus can be detected in the cytoplasm of infected cells by fluorescence antibody technique. This disease is transmitted by respiratory droplets and has the characteristics of wide spread, high infection rate, and long duration. It is spread and epidemic in all countries in the world, almost appearing once or twice a year, and is one of the viruses causing serious lower respiratory tract infections in infants.

　　This disease often complicates with lower respiratory tract infection, and the condition is serious. It is mainly manifested as wheezing, and severe cases may lead to respiratory obstruction, atelectasis, hypoxia, cyanosis, respiratory failure, and even asphyxial death. Therefore, once the above conditions are found, active symptomatic treatment should be carried out to breathe oxygen, relax spasm, and relieve asthma. In some children, meningitis or myelitis may occur.

　　This disease is more common in infants and young children, with more than half being infants under 1 year old, and males are more than females, with a ratio of about 1.5 to 2. The incubation period is about 4 to 5 days. In the early stage, symptoms such as cough and nasal congestion can be seen, and about 2/3 of the cases have a high fever, which can reach up to 41℃, but the fever is generally not persistent and is easy to be relieved by antipyretics. The duration of high fever is usually 1 to 4 days, with a few cases lasting for 5 to 8 days. About 1/3 of the children have moderate fever, which usually lasts for 1 to 4 days, and the duration of fever in most cases is 4 to 10 days. Mild cases have slight respiratory distress and neurological symptoms, while moderate to severe cases have more obvious respiratory distress, coughing, cyanosis of the lips, flaring of the nostrils, and tracheal depression. A few severe cases may also develop heart failure, with fine or coarse, medium diaphoresis on chest auscultation, and generally no dullness on percussion. A few cases may have hyperresonance.

　　This disease has a strong infectivity. To prevent the occurrence of the disease, attention should be paid to strictly disinfecting the respiratory secretions of the children. At the same time, breast milk feeding can increase the baby's antibodies, and breastfeeding should be encouraged. Vaccination with attenuated live vaccine can produce neutralizing antibodies in 95% of children, and antibodies can also be detected in nasal secretions. In recent years, a new strain of temperature-sensitive (ts) fission has been developed for aerosol inoculation, which can be effective in protecting children and adults with antibodies, but is ineffective for infants with negative serum antibodies.

　　X-ray examination shows that most of the lungs have small spot-like shadows, and large ones are extremely rare, about 1/3 of the children have varying degrees of emphysema.
　　Blood count examination shows that the total white blood cell count is generally between (5～15)×109/L (5000～15000/mm3), most of which is below 10×109/L (10000/mm3), and the neutrophils are below 70%.

　　For infants and young children with illness, breast milk feeding can enhance the child's resistance.
　　Patients with respiratory syncytial virus infection in adults should eat light foods. The diet should be light, with more fresh vegetables and fruits, beans, and mushroom foods. Eat more foods rich in vitamins A, B, and C. More loofah, purslane, red beans, and winter melon should be eaten.
　　Patients with respiratory syncytial virus infection should avoid greasy and spicy foods. Eat less or no fried and crispy foods such as oil sticks, oil cakes, and five-spice foods. Eat less or no fishy foods such as seafood, crucian carp, beef, mutton, and dog meat.

　　Currently, there is no specific treatment. For respiratory virus infections, in addition to general treatments such as bed rest during the fever period and increased water intake,对症治疗 is mainly applied: physical or drug降温 can be given for high fever, and acetylsalicylic acid compound (compound aspirin) can be taken orally for severe headache. When bronchiolitis and pneumonia present with shortness of breath, asthma, and cyanosis, oxygen therapy, antispasmodics, expectoration to keep the airway clear should be provided, and tracheotomy and artificial respiration may be performed if necessary. For those with heart failure, cardiotonic agents should be administered. Effective antimicrobial drugs should be given promptly for secondary bacterial infections.