It is now a critical period for the prevention and control of New Coronary Pneumonia and a season of high influenza incidence. When New Coronary Pneumonia meets the flu season, how to distinguish New Coronary Pneumonia from Influenza and Common Cold? How to correctly understand New Coronary Pneumonia and take scientific and effective protective measures? Recently, Xinhua launched the special topic "Experts in Warfare". In the fifteenth issue, Professor Kuang Jiulong, chief physician of the Department of Respiratory Medicine of the Second Affiliated Hospital of Nanchang University, was invited to share with us the topics related to New Coronary Pneumonia.
Professor Kuang Jiulong, Chief Physician, Department of Respiratory Medicine, Second Affiliated Hospital of Nanchang University
Xinhuanet: What is the cause of the new coronary pneumonia?
Jiulong: At the end of 2019, a number of unexplained cases of pneumonia were found in Wuhan. After identification of the pathogen and investigation of the etiology, it was confirmed that it was caused by a new coronavirus infection. The World Health Organization officially named the disease as "COVID-19" (Corona Virus Disease 2019), which China calls the new coronavirus pneumonia, referred to as "new coronary pneumonia". Coronavirus is a type of virus that exists in nature. It is named because it looks like a crown under the electron microscope. So far, coronavirus only infects humans and vertebrates, and it can cause respiratory, digestive, and nervous system diseases in humans and vertebrates.
When it comes to coronaviruses, one might think of SARS in 2003, and MERS, which is popular in the Middle East. They are also coronaviruses, but new coronary pneumonia is different from SARS and MERS. Although they have a certain degree of homology, they are less than 80% similar, so they are not the same virus.
Xinhuanet: How does new coronary pneumonia spread?
Situation Kowloon: Coronavirus can be passed from person to person, which is determined by the biological laws of the virus. Currently, epidemiological investigations have confirmed that the main route of transmission is the transmission of droplets from the respiratory tract, through coughing, sneezing and close contact, especially It is contact with the patient and the source of infection without safety protection, such as touching the surface of the contaminated object, and then touching the mouth, nose, eyes, etc. through the contaminated hand.
In addition, there may be aerosol transmission in a relatively closed environment for a long time of exposure, but it is not the main transmission route. Despite the detection of viruses in feces, digestive tract transmission is currently subject to further observation and confirmation by epidemiology.
It is precisely because the disease can be transmitted from person to person, so to control this disease, we must first interrupt the transmission path, so that it does not have the conditions for human transmission, we must isolate the source of infection, cut off the transmission path, you can effectively control the spread of the disease.
Xinhuanet: Who is susceptible to new coronary pneumonia?
Situation Kowloon: People who have close contact with suspected cases and confirmed cases. The first category, people who live, study, and work closely with suspected and confirmed cases; the second category, medical treatment, nursing, and visiting cases, such as medical personnel who have not taken effective protective measures; the third category, other patients and other cases Accompanying personnel; the fourth category is the person who is on the same vehicle as the case and has close contact; the fifth category is the person who is deemed eligible by the investigator after the investigation.
To determine whether it is a close person, it is necessary to analyze the possibility of infection, comprehensive consideration of multiple factors such as the method of contact, the degree of exposure, and the clinical manifestation of the case to determine whether it is a close contact.
Xinhuanet: What damage will the new coronary pneumonia cause to the human body?
Situation Kowloon: New coronary pneumonia starts in the lungs, and it has many similarities to the flu. After infection, the patient may develop symptoms such as coughing, sneezing, and fever, and eventually develop pneumonia. There are three stages. The first stage is the virus replication stage, the second stage is the lung injury caused by the overreaction of the immune system, and the third stage is the repair.
First of all, the lung is the original point of infection with new coronary pneumonia. This disease usually attacks the lungs in three stages: the virus replication period, the immune system overreaction period, and the lung injury period. In the early stage of infection, the new coronavirus will quickly invade the human lung cells. Pulmonary pneumonia appears, accompanied by shortness of breath and other symptoms. Then, in the second stage, the immune system starts to work. After the virus invades, our body will start fighting, import immune cells to the lungs, remove the damage, and repair lung tissue. Under normal circumstances, the inflammation process is strictly controlled and limited to the infected area. But sometimes the immune system gets out of control, and immune cells kill everything, including healthy tissue. In the third stage, lung damage will continue, eventually leading to respiratory failure. Even without death, some patients will suffer permanent lung damage.
Secondly, "cytokine storm", cytokines such as TNF-α, IL-1, etc. refer to the proteins used by the immune system to issue an alarm, they are responsible for focusing the immune system to the site of infection. Next, immune cells kill the infected tissue and save the rest of the body. The daily work of the immune system is to clear infections and rely on the immune system to protect itself when the body encounters threats. "Cytokine storm" refers to the phenomenon that after the body is infected with microorganisms, a variety of cytokines in the body fluid are rapidly produced. If the immune system is activated to the limit or loses control, it will harm the host, extreme Immune attack, causing severe lung damage, leading to acute respiratory failure and multiple organ failure. In addition to the characteristics of lung lesions, there are at least one other symptom: increased liver enzymes, decreased white blood cell and platelet counts, decreased blood pressure, acute kidney injury, myocardial damage, cardiac arrest, that is, the immune system not only attacks infected cells, Not even healthy organizations.
Finally, there is multi-organ dysfunction. After the cytokine storm is generated, the cytokine storm caused by the inflammation will enter the circulatory system, causing systemic problems in multiple organs, including renal failure, myocardial damage, heart failure, and liver function damage. 1. Coagulation dysfunction.
Xinhuanet: With respiratory symptoms, how do you tell if you are infected with new coronary pneumonia?
Situation Jiulong: Based on the current epidemiological investigation, the incubation period is 1-14 days, mostly 3-7 days. Fever, fatigue, and dry cough are the main symptoms. A few patients are accompanied by occlusion, runny nose, sore throat, myalgia, and diarrhea. Severe patients often develop dyspnea or hypoxemia 1 week after the onset of the disease. In severe cases, they rapidly progress to acute respiratory failure (acute respiratory distress syndrome), sepsis, and multiple organ failure. It is worth noting that some patients have mild onset symptoms, no fever, and no pneumonia. Most patients are mild to mild. The prognosis is good, and a few patients are critically ill or even die.
If there are early clinical manifestations, such as fever, fatigue, and dry cough, it does not mean that they have been infected. However, if you have fever (axillary body temperature ≥37.3C), cough, shortness of breath and other acute respiratory infection symptoms, and have a history of traveling or living in Wuhan, or have been exposed to fever and respiratory symptoms from Wuhan within 14 days before the onset, or If a small-scale aggregation occurs, you should go to the local designated medical institution for investigation, diagnosis and treatment.
Xinhuanet: In the current period of frequent influenza, how to distinguish influenza from new coronary pneumonia?
Condition Jiulong: The clinical symptoms of cold are mainly nasal congestion, runny nose, sneezing, and the symptoms are mild. There are no obvious symptoms such as fever, headache, joint pain, and general malaise, and there is no obvious effect on physical strength and appetite. People with colds generally have more severe upper respiratory symptoms, and the systemic symptoms are generally mild and generally not life-threatening. Symptoms will be effectively improved after taking the medicine, and they will usually heal themselves in about 7 days.
Influenza is a respiratory infection caused by influenza virus infection, which not only causes upper respiratory infections, but also lower respiratory infections. The two seasons of winter and spring are also influenza epidemic seasons, which can be generally divided into influenza A and influenza B. Influenza patients usually have a more acute onset, and the symptoms are more severe. The symptoms are high fever, cough, and sore throat. Most of the symptoms will be fever, and the body temperature can rise to more than 39 degrees, accompanied by headache, body aches, systemic symptoms are more severe, and respiratory symptoms are relatively mild.
The early symptoms of the new coronavirus pneumonia have only a little fever, cough, chills and physical discomfort, but as the course of the disease develops, not only will the symptoms of fever and cough, but also the symptoms of fatigue, and about 50 after infection with the new coronavirus % Of patients have chest tightness and difficulty breathing after 3 to 5 days. In severe cases, rapid progression to acute respiratory distress syndrome (ARDS), septic shock, metabolic acidosis that is difficult to correct, and coagulopathy. After a week, the course of the disease will gradually worsen and develop into pneumonia, or even severe pneumonia, and there will be accelerated breathing, respiratory failure, multiple organ damage, and even death.
This is a period of high incidence of colds and flus, so you must carefully judge your condition. For the judgment of the epidemic situation of respiratory tract infectious diseases, special attention should be paid to (1) whether there is travel history or residence history of Wuhan city and surrounding areas within 14 days before the onset of the disease, or other communities with reported cases; People with viral infections (positive nucleic acid test, that is, diagnosed patients) have a history of exposure; (3) Whether they have been exposed to patients from the city of Wuhan and surrounding areas, or from patients with fever or respiratory symptoms in the community where cases have been reported; (4) ) Whether there is clustered disease.
Xinhuanet: Who are susceptible to new coronary pneumonia?
Situation Kowloon:
1. The elderly group
Pay attention to the current "age distribution of people infected with the new coronavirus". The proportion of the "elderly population" is the largest. The prevalence and mortality of elderly patients belong to the "largest share of the age distribution." Relatively speaking, the physical capacity of the elderly population is in a declining stage, and the organ and immune capabilities are lower than that of the young people, so they are more likely to be "beaten by the new coronavirus", and the risk of illness will naturally be higher.
2. Crowds in crowded places
For the "new coronavirus", the mode of infection is more "droplet" infection, therefore, where there are many people, the risk of infection with the "new coronavirus" will naturally be higher. In real life, there are many people who are “unwilling to be lonely” and are always used to staying and playing in places where there are many people. Some people may also be due to special reasons for work. However, it is more likely to occur in closed, ill-flowing and crowded places. In the case of "virus infection", there are more people and more viruses; if the space is small, the number of virus units in the space is large, so the risk of infection will naturally increase.
3. People with "certain basic diseases"
According to data reports from official media, it is found that among the patients with "serious new coronavirus pneumonia", a large part of the population belong to patients who have problems with respiratory diseases, hypertension, diabetes, cirrhosis, etc.; there are serious underlying diseases The people who belong to the "New Crown Susceptible People" need to pay attention to.
4. People with poor living habits and low autoimmunity
I don't like exercise in my daily life. I usually sit for a long time, smoke and drink alcohol on weekdays. It's easy to catch a cold by someone next to me, which means "the resistance is relatively low". This kind of population is also a susceptible group of new coronavirus. Such people need to adjust their lifestyle and dietary patterns, exercise more, eat, sleep and balance arrangements to enhance their defenses against the virus. In addition, children such as children, pregnant women and medical staff who are in contact with patients are also "susceptible people of the new crown virus". These people need to "focus on prevention and control" in their lives to avoid being attacked by the epidemic. (Wang Gu)