The top ten symptoms of COVID-19 include fever, dry cough, fatigue, decreased sense of smell and taste, stuffy nose, runny nose, sore throat, conjunctivitis, myalgia and diarrhea.
System of Health Education of Ningbo Center for Disease Control and Prevention
2. The source and route of transmission of infection in COVID-19.
According to the current epidemiological investigation and research results, the main sources of infection in COVID-19 are confirmed cases and asymptomatic infected people in COVID-19; The main route of transmission is through respiratory droplets and close contact, and contact with items contaminated by virus can also cause infection; Contact with high concentration aerosol in a relatively closed environment may spread through aerosol. Because it can be separated into COVID-19 in feces and urine, it should be noted that it may cause contact transmission or aerosol transmission and cause environmental pollution.
3. What's the difference between COVID-19 and influenza and common cold?
Common cold refers to diseases with symptoms of upper respiratory tract of nasopharynx as the main symptoms, such as nasal congestion, runny nose, sneezing, no obvious fever, no obvious headache, joint pain and general malaise.
Influenza is a disease caused by influenza virus infection. Influenza patients have acute onset and severe symptoms, including headache, muscle weakness, loss of appetite and other obvious symptoms. For the elderly, children, pregnant women or people with basic diseases, influenza can also lead to severe pneumonia and even death.
After being infected with COVID-19, the main symptoms are fever, fatigue and dry cough. The first symptoms of some patients are loss of sense of smell and taste, and a few patients are accompanied by symptoms such as stuffy nose, runny nose, sore throat and diarrhea. Mild patients may have symptoms such as low fever, mild fatigue, smell and taste disorders; Severe patients often have symptoms such as dyspnea and/or hypoxemia one week after onset.
4. What is the definition of suspected cases in COVID-19?
The definition of suspected cases is divided into three situations:
1, any of the following epidemiological history 1, any of the following clinical manifestations;
2, no clear epidemiological history, in line with the following three clinical manifestations;
3. Meet any two of the following clinical manifestations, and the COVID-19-specific IgM antibody is positive (those who have been vaccinated with COVID-19 vaccine recently will not be used as the reference standard).
Epidemiological history:
① Travel history or residence history in the community where the reported case is located within 0/4 days before onset/KLOC-;
② Contact history with COVID-19 infected persons and asymptomatic infected persons within 0/4 days before onset;
③ Patients with fever or respiratory symptoms reported by their own cases in the community within 0/4 days before onset/KLOC-;
④ Aggregative onset (2 or more cases of fever and/or respiratory symptoms occurred in small areas such as home, office and school class within 14 days).
Clinical manifestations:
① Clinical manifestations related to COVID-19, such as fever and/or respiratory symptoms;
② COVID-19 imaging features;
③ At the initial stage of the disease, the total number of white blood cells is normal or decreased, and the lymphocyte count is normal or decreased.
5. What is the definition of confirmed cases in COVID-19?
On the basis of suspected cases, there is one of the following etiological or serological evidence:
1. COVID-19 nucleic acid positive;
2. COVID-19-specific IgM antibody and IgG antibody were positive in those who were not vaccinated with COVID-19 vaccine.
6. What is the definition of asymptomatic infection?
Asymptomatic infection refers to symptoms and signs that have no relevant clinical manifestations, such as fever, dry cough, sore throat, etc., which can be perceived or clinically recognized. CT imaging has no COVID-19 imaging characteristics, but COVID-19 pathogen test is positive.
7. Why does COVID-19 mutate frequently?
COVID-19 is an RNA virus, which is characterized by high variation.
A brief comparison of several VOCs (mutants of concern);