Pneumonia caused by novel coronavirus is a new disease, and the "fight against pneumonia" is the focus of all the people's attention. What clinical treatment options are available? Is it possible to be reinfected after discharge from the hospital? ...... recently, Xinhua launched a special topic "Fight the Epidemic", and invited Wen Guilan, director of the Department of Respiratory and Critical Care Medicine of the First Affiliated Hospital of Nanchang University, to share with us how to diagnose and treat the new coronavirus.
Xinhua: How does the novel coronavirus spread in the population?
Wen Guilan: There are three ways of transmission of novel coronavirus. The first is droplet transmission. When a person infected with the new coronavirus speaks, breathes, sneezes or coughs, droplets will be produced, which contain the virus, and when other people come into close contact with these droplets, they will spread, which is droplet transmission. The second way of transmission is contact transmission. When our hands touch the body fluids, secretions, and excretions of patients with Newcastle pneumonia, and then touch their own skin and mucous membranes, especially the mucous membranes, such as the eyes, mouth, and nose, it is easy to get infected with Newcastle virus. The third way of transmission is aerosol transmission. When a person stays in a confined environment for a relatively long time, it will easily lead to aerosol transmission.
Xinhua: How long is the incubation period of Newcastle pneumonia? After this incubation period is it still infected?
Wen Guilan: The incubation period for new coronavirus pneumonia is 1 to 14 days, with an average of 3 to 7 days. The majority of people will not be infected after 14 days, but there are very few people who can have an incubation period of more than 14 days.
Xinhua: What are the clinical manifestations of novel coronavirus pneumonia? Is it specific?
Wen Guilan: Most of the clinical manifestations of novel coronavirus pneumonia are fever, dry cough, weakness, a few patients have nose congestion, cough, sore throat and muscle aches. Its clinical manifestations are not specific, and it is difficult to distinguish it from the common cold and influenza. Severe patients can have hypoxia, persistent respiratory distress, shock, and even multi-organ failure.
Xinhua: What laboratory tests and ancillary tests are needed to aid in the diagnosis of novel coronavirus pneumonia? What are the characteristics of these tests?
Wen Guilan: The first type of tests are general hematological tests. These include routine blood, liver and kidney function, coagulation function, C-reactive protein, PCT and so on. The second type of examination is imaging examination, and CT examination of the chest should be performed. The third type of examination is pathogenetic testing. Specimens from the respiratory tract are taken: nasopharyngeal swabs, oropharyngeal swabs, sputum or bronchoalveolar lavage fluid for viral nucleic acid testing.
Hematologically, patients with neoconiosis show normal or decreased white blood cells, decreased lymphocytes, and in severe cases, elevated myoenzymes, liver enzymes, and elevated myoglobin. Imaging manifests as multiple patchy imaging, interstitial changes in both lungs, progressing to large ground glass shadows, and even solid lung changes. Nucleic acid testing is performed by RT-PCR (fluorescent PCR) to check for novel coronavirus nucleic acid, and a positive result for both targets confirms the diagnosis.
Xinhua: Suspected patients need to be diagnosed differently, what conditions are met to be a suspected case?
Wen Guilan: The diagnosis of novel coronavirus includes the following aspects: first, epidemiological history; second, clinical manifestations; third, changes in chest imaging; fourth, hematological changes.
The epidemiological history includes four items: first, a history of contact or travel in Wuhan or surrounding areas or communities where cases have been reported; second, a history of close contact with people infected with novel coronavirus; third, a history of close contact with people from Wuhan or surrounding areas or communities where cases have been reported who have fever or respiratory symptoms; and fourth, a history of aggregated illness.
On the basis of suspected cases, a positive fluorescent PCR test for novel coronavirus nucleic acid, or genome sequencing with high homology to novel coronavirus, is a confirmed patient.
Xinhua: Why is there a false negative?
Wen Guilan: There are various reasons for such false negatives, firstly, the quality of the kit, then the problem of specimen collection, and thirdly, the problem of laboratory operation.
To improve the diagnosis rate and reduce false negatives, first of all, we should collect specimens from the lower respiratory tract. Compared with nasopharyngeal swabs or oropharyngeal swabs from the upper respiratory tract, the positive rate of sputum specimens is higher. After the specimen is collected, it should be sent for testing at low temperature and quickly. It is important to strengthen the quality control in the laboratory to improve the positivity rate. Another good way is to test multiple times, which will definitely increase the positive rate.
Xinhua: The clinical manifestation of novel coronavirus pneumonia varies, how to classify it?
Guilan: New coronavirus pneumonia is divided into mild, common, heavy and critical according to its severity.
The mild type refers to the clinical symptoms are mild and there is no pneumonia on the imaging. Normal type refers to mild clinical symptoms, but with imaging pneumonia. The severe type is defined as a respiratory rate greater than or equal to 30 breaths per minute, at rest, meaning an oxygen saturation less than or equal to 93%, or an oxygen and index less than one of 300. Critical type refers to respiratory shock, respiratory failure, requiring mechanical ventilation, or multiple organ failure, requiring admission to ICU, satisfying one of them.
Xinhua: What are the clinical treatment options for patients with severe and critical forms of Newcastle pneumonia and how effective are they?
Wen Guilan: There is no specific medicine for most viruses, and the same is true for new coronavirus pneumonia. The main treatment for it is mainly supportive symptomatic and antiviral treatment. The general treatment includes close monitoring of vital signs, timely oxygenation, as well as nutrition, and regular review of routine blood tests, blood biochemistry, chest CT, and so on. We do not recommend the use of three or more antiviral drugs at the same time, and special attention should be paid to the efficacy and adverse reactions when using antiviral drugs. Patients with severe disease should be actively prevented and treated for complications and secondary infections, and patients with poor results of general oxygen therapy need to be ventilated with non-invasive or invasive mechanical ventilation. Short-term glucocorticosteroids can be used as appropriate for patients with rapid disease progression and severe inflammatory reactions. For patients with septic shock, circulatory support is required. Extracorporeal membrane oxygenation (ECMO) may be used for particularly poor pulmonary function and severe respiratory failure. If conditions allow, plasma therapy for recovered patients can be considered.
Xinhua: After treatment, what conditions can be met for discharge?
What are the precautions after hospitalization, and will there be reinfection after discharge?
Wen Guilan: The criteria for discharge include: first, the body temperature is normal for more than 3 days; second, the respiratory symptoms are significantly improved; third, the lung imaging, the inflammation is obviously absorbed; fourth, the viral nucleic acid test of the respiratory specimen is negative for more than two consecutive times, then the isolation and discharge can be released.
After discharge from the hospital, the patient should be closely observed for two weeks and return to the hospital for review in the second and fourth weeks, then during the observation period, avoid close contact with others and avoid going out.
Generally speaking, after the virus infection, antibodies will be produced in about two weeks, which can last for six months or even longer. (Wang Qi)
