Symptoms of COVID-19

Main article: Coronavirus COVID-19

COVID-19 symptom groups

A study by the "Vienna Medical University" in November 2020 made it possible to establish the relationship between individual groups of coronavirus symptoms. A total of 7 related groups were identified:

1) symptoms as in influenza;

2) symptoms as in colds;

3) muscle and joint pain;

4) inflammation of the eyes and mucous membranes;

5) lung problems;

6) GI problems;

7) loss of smell and taste.

Different groups can intersect, but not always. It turns out that, for example, "loss of taste and smell" or "muscle pain" may be the only symptom of the disease, even without raising the temperature.

2021: Scientists explain why infected COVID-19 lose their sense of smell

In May 2021, scientists at the Pasteur Institute, the National Center for Scientific Research, the University of Paris and other scientific organizations published the results of a large study aimed at explaining the mechanisms of loss of smell (anosmia) in coronavirus-infected COVID-19.

According to the researchers' findings, published in the journal Science Translational Medicine, coronavirus affects sensory neurons and causes inflammation of the epithelium and part of the nervous system responsible for sense of smell. In some patients, anosmia was associated with prolonged inflammation of the epithelium and the presence of the virus in these cells.

The study showed that once the virus enters the olfactory bulb, it spreads to other nerve structures, where it causes a serious inflammatory reaction.

Olfactory mucosa in a healthy person (left) and in an infected COVID-19 (right)

Due to viral infection, sensory neurons lose olfactory cilia, which are necessary for "catching" stimulus molecules. The virus also penetrates sensory neurons, disrupting their functions, and contributes to the death of epithelial cells as a result of apoptosis (programmable cell death). Subsequently, the coronavirus penetrates the olfactory bulb, where it provokes inflammatory reactions, and from there it spreads to other nerve structures.

The penetration of the virus through olfactory bulbs into the brain explains why some patients develop different psychological clinical signs (anxiety disorders, depression) or neurological symptoms (cognitive decline, predisposition to develop neurodegenerative diseases).

Loss of sense of smell in COVID-19 infection may persist for months in some patients and may be associated with viral preservation and inflammation in the olfactory mucosa, the scientists said.^[1]

2020: Study of symptoms in China at the beginning of the epidemic

The symptoms of COVID-19 are uncertain, and the development of the disease can range from asymptomatic to severe pneumonia and death. According to surveys of 55,924 patients in China (at the end of February 2020), signs and symptoms include:

• fever - 88%,
• dry cough - 68%,
• abundant sputum expectorization - 33%,
• severe respite - 19%,
• myalgia - 15%,
• heavy angina - 14%,
• severe headache - 14%,
• vomiting - 5%,
• severe diarrhea - 4%,
• hemorrhage - 1%.

The difficulty lies in the absence in COVID-19 of any specific sign characteristic only of this disease. All the indicated signs can be manifested in connection with diseases of a wide variety of diseases, including easily tolerated by the body.

People with COVID-19 feel symptoms on average after 5-6 days after infection, ranging from 1 to 14 days. The vast majority of those infected with coronavirus, including those of older age, either tolerate the disease asymptomatically or feel a mild malaise or recover without serious consequences. According to laboratory studies, even older persons in about 4/5 cases have either asymptomatic or moderately pronounced form, including in the form of pneumonia. At the same time, 14% have a severe form of disease, requiring connection to a ventilator.

If you have a runny nose with a cold, you cannot be a carrier of coronavirus infection. Coronavirus pneumonia is a dry cough without a runny nose. This is the easiest way to determine.

Physician advice on coronavirus:

1. The virus is large enough in size (the cell diameter is about 400-500 nm), so a conventional honey mask can in principle filter. If the infected sneezes in front of you or passes at a distance of up to 3 meters from you, the retarder step of the infection will simply fall to the ground, will not be able to fly.

2. If the virus hit the surface of the metal, it will live at least 12 hours. Therefore, if you are in contact with any metal surface, wash your hands thoroughly with soap.

3. The virus can remain active on the tissue for 6-12 hours. Regular washing powder should kill the virus. Winter clothes, dry in the sun enough to kill the virus.

About the symptoms of the disease directly - pneumonia caused by coronavirus:

1. After penetration into the throat, a dry throat may appear, which occurs in angina. Will last 3-4 days

2. Then the virus will merge with nasal fluid, enter the trachea, and then into the lungs, cause inflammation of the lungs. This process will take 5 to 6 days.

3. With coronovirus pneumonia, high fever and difficulty breathing appear. Nasal congestion is not like normal congestion, there is a feeling that you are drowning in the water. In this case, you should immediately consult a doctor.

Common signs of infection include:

• respiratory symptoms,
• fever,
• dry cough,
• difficulty breathing,
• shortness of breath.

In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure, and even death.

When should you be careful?

According to WHO recommendations, special attention should be paid to the state in the following cases:

• in severe acute respiratory infection (fever, cough), if a person was in the city of Wuhan 2 weeks before symptoms appeared, and also if suspicious symptoms appeared in a medical officer who worked in an environment where severe acute respiratory infections of unknown etiology are treated;
• in any acute respiratory disease, if a person was in contact with a virus-infected patient, worked or visited a medical facility 2 weeks before symptoms appeared.

"You can understand that you are sick by the following symptoms, they are similar to the symptoms of influenza: pronounced intoxication, fever, dry unproductive cough, respiratory failure develops quickly. When these complaints appear, it is necessary to consult a doctor, "says Olga Sinitsyna, an infectious disease specialist at Medicine JSC (Roitberg Clinic).

Notes