Coronavirus infection

　　Coronavirus is a single-stranded RNA virus, resembling a crown or mitre. There are at least 6 serotypes of human coronaviruses, including 229E and OC43, which are widely distributed. The virus is difficult to isolate initially, and it can only be propagated by culturing with complete cilia human embryo trachea. After multiple passages, the 229E strain can grow on human embryo diploid fibroblasts, while the OC43 and OC38 strains can grow in rat brains.

　　After respiratory viruses侵入the respiratory surface ciliated epithelial cells of humans, they replicate and spread within them, directly causing damage to infected cells and resulting in local lesions or systemic toxic blood symptoms. The tissue damage caused by certain viral infections may be mediated by the body's immune response, such as the direct destruction of respiratory ciliated epithelial cells by respiratory syncytial virus, which is the mildest but can cause severe respiratory diseases in infants and young children; the most susceptible age is also the stage with the highest level of maternal antibodies; after vaccination, the condition of natural infectors may worsen, etc., all indicating that the onset may be related to immune response. The pathological changes of respiratory virus infection include congestion, edema, exudation, and mononuclear cell infiltration of the nasal, pharyngeal, and laryngeal mucosa. Some cells may undergo变性, necrosis, and desquamation. Inclusions can be seen in the cytoplasm or nucleus of epithelial cells. The degree of lesion is related to the type, strain, and site of infection of the virus. Mild cases may regenerate the epithelial cells and recover within a few days. If the lesion involves the bronchioles, epithelial cell necrosis and desquamation may occur, with widespread mononuclear cell infiltration in the bronchiolar wall. Fibrous protein, cell fragments, and thick mucus can block the lumen, leading to atelectasis and emphysema. Viral pneumonia initially presents with progressive reduction of cilia, vacuolation of epithelial cells, followed by epithelial cell变性,实质性 necrosis and atrophy of alveoli, and necrosis and thickening of the alveolar wall. Interstitial edema and infiltration of monocytes and lymphocytes can also be seen. Concurrent bacterial infection may cause mucosal congestion, neutrophil infiltration, and purulent secretions. In severe cases, lung abscess, sepsis, and purulent changes in multiple organs may occur.

　　Complications of COVID-19 infection include frontal sinusitis, otitis media, chronic bronchitis, pneumonia, and pleural effusion.

　　1, Frontal sinusitis

　　Frontal sinusitis is characterized by a feeling of stuffiness in the forehead, more pronounced on the affected side. If the drainage of the frontal sinus is obstructed, headaches may occur, with marked nasal congestion, usually more severe in the morning, and often accompanied by persistent nasal congestion on the affected side.

　　2, Otitis media

　　Otitis media is most commonly manifested as a feeling of stuffiness or blockage in the ear, decreased hearing, and tinnitus. It often occurs after a cold or without realizing it. Sometimes, a change in head position can improve hearing, with an enhanced sense of self-hearing. Some patients may have mild ear pain. Children often show symptoms of delayed hearing or inattention.

　　3, Other

　　If secondary bacterial infection occurs, or in patients with a long history and severe symptoms, it may develop into chronic bronchitis, pneumonia, and in severe cases, lead to complications such as pleural effusion.

　　The incubation period of COVID-19 infection is generally 2 to 5 days. The main symptoms are upper respiratory tract infection, which may be accompanied by fever, chills, headache, runny nose, sore throat, and cough. Most patients have relatively mild symptoms, with about 77% presenting with mild illness, 15% to 20% with moderate symptoms of common cold, and 8% to 9% with severe illness. The course of the disease is 2 to 18 days, on average one week. A small number of patients may have complications such as bronchitis, pneumonia, diarrhea, pleural effusion, etc. Special attention should be paid to children. If a child's cold occurs in winter or spring, even if it is mild, without fever, this disease should be considered.

　　It is almost impossible to prevent COVID-19 infection with a vaccine because there are too many strains, and there is no cross-immunity between them. Apart from the adenovirus vaccine being tested, there is no effective vaccine for other respiratory viruses. A vaccine targeting the respiratory syncytial virus surface glycoprotein is under development. The main measures to prevent respiratory virus infection at present are:

　　1, Popularize health knowledge, strengthen physical exercise, and avoid catching a cold.

　　2, Avoid visiting others' homes and public places during the epidemic period.

　　3, Patients should wear masks or respiratory isolation.

　　The examination methods for coronavirus infection can refer to those for rhinovirus infection, and can include blood routine, serological examination, etc.

　　1, Blood test: normal white blood cell count, slightly elevated neutrophils, moderate acceleration of erythrocyte sedimentation rate.

　　2, Other auxiliary examinations: X-ray examination, increased pulmonary纹理, no other abnormalities observed.

　　3, If possible, isolate the virus or determine the neutralizing antibody in serum. Diagnosis requires virological examination. Isolating the virus from nasopharyngeal secretions 2-4 days after onset is the most reliable method, detection of viral RNA by molecular biological methods helps in early diagnosis, and double-serum tests for specific antibodies can be used for epidemiological surveillance.

　　Dietary recommendations for patients with coronavirus infection should be light and easy to digest, drink plenty of water, eat more fresh fruits and vegetables, and avoid spicy, greasy, and hot foods. For patients with coronavirus infection, delicious medicinal foods can also be used to alleviate symptoms.

　　1, Orange and Ginger Drink

　　Composition: Orange cake 2 pieces, ginger 20 grams.

　　Usage: Boil the two ingredients in water. Take one dose per day, for 3 doses in a row.

　　2, Ginger Porridge

　　Composition: Fresh ginger 25 grams, glutinous rice 100 grams, brown sugar as needed.

　　Usage: Rinse the glutinous rice clean, add water and boil over high heat, then add ginger juice, continue to simmer over low heat until the porridge is done, season with brown sugar and eat.

　　3, Sweet Bean Rice Porridge

　　Composition: Mung bean 150 grams, brown sugar as needed.

　　Usage: Boil mung bean in water for about 1 hour, add brown sugar, then boil for another 15 minutes, eat while hot, stay in bed and sweat.

　　4, Mint Rice Porridge

　　Composition: Mint 5 grams, glutinous rice 50.

　　Usage: Boil the glutinous rice first, wait until it is cooked, add mint, then boil for another 5 minutes, eat on an empty stomach.

　　5, Bitter Melon and Pork Soup

　　Composition: Bitter melon 200 grams, lean pork 50 grams.

　　Usage: Wash the lean pork and cut into slices, cut the bitter melon into slices, then cook the soup together for consumption. Take twice a day.

　　6, Ginger and Radish Soup

　　Composition: Ginger 25 grams, radish 50 grams, a little brown sugar.

　　Usage: Wash and slice ginger and radish, add water and boil for 15 minutes, then add a little brown sugar and boil for a while.

　　7, Beef Tripe and Cabbage Soup

　　Composition: Beef tripe 250 grams, fresh cabbage 500 grams, ginger 3 slices, a little sesame oil and salt as needed.

　　Usage: Scrape the black skin off the beef tripe, wash and chop; wash the fresh cabbage and cut into segments. Fry the beef tripe in oil with ginger, then add it to a pot of boiling water with the cabbage, bring to a boil over high heat, then reduce the heat and simmer for 1 hour, season with salt to taste. Serve with meals.

　　8, Hoelen and Mung Bean Soup

　　Composition: Mung bean 50 grams, hoelen 10 grams.

　　Usage: Boil the two ingredients in water, add some sugar as needed before serving, take one dose per day.

　　Currently, there is no effective antiviral drug for the treatment of coronavirus infection. The existing antiviral drugs have unsatisfactory effects and significant side effects, and most respiratory tract viral infections are self-limiting, so the use of existing antiviral drugs is not significant. Ribavirin is recommended for the treatment of severe respiratory syncytial virus infection in infants. Ribavirin is a synthetic nucleoside antiviral drug that is effective against certain types of herpesviruses, poxviruses, influenza viruses, parainfluenza viruses, rhinoviruses, respiratory syncytial viruses, enteroviruses, and other viruses. The mechanism of its antiviral action is not yet clear. It is mainly used for aerosol inhalation treatment of severe respiratory syncytial virus infection in infants, with daily inhalation for 12 hours for 3 days, which can alleviate symptoms and shorten the shedding period. Animal experiments have shown that it can cause malformations, and pregnant women are prohibited from using it. In addition to bed rest and plenty of fluid intake during the fever period, respiratory tract viral infections are mainly treated symptomatically: high fever can be treated with physical or drug-induced hypothermia, and severe headache can be treated with oral acetylsalicylic acid (complex aspirin). When symptoms such as dyspnea, asthma, and cyanosis occur in bronchiolitis and pneumonia, oxygen therapy, antispasmodics, and expectoration to keep the airway open should be given. Tracheotomy and artificial ventilation may be necessary if necessary, and cardiotonic agents should be given to those with heart failure. Effective antibacterial drugs should be given promptly to those with secondary bacterial infections.

　　Coronavirus infections generally have a good prognosis. Respiratory tract infections or secondary bacterial infections are more severe. The prognosis is poor for infants, the elderly, those with pre-existing cardiovascular and pulmonary diseases, or those with weakened immune function. Most patients with atypical pneumonia are relieved or clinically cured and discharged after comprehensive treatment. A few patients may progress to ARDS (less than 20%), and there have been cases of death. The mortality rate of severe patients seems to be related to the underlying diseases of the patients, and clinical findings show that patients with underlying diseases such as diabetes and coronary heart disease have a higher mortality rate. Univariate analysis of factors affecting prognosis found that low absolute neutrophil count at the onset of disease in elderly men and other factors are predictive factors for severe illness and death. Multivariate analysis found that only old age (patients over 40 years old are more likely to develop severe illness) and low absolute neutrophil count are predictive factors for poor prognosis.