Useful material for those who suspect that they have inconspicuously suffered COVID-19.
How to understand that you have already had a coronavirus
Physician at the Semeynaya clinic
At the beginning of the pandemic, when doctors did not know what to grab first, a mass of symptoms penetrated into the mass consciousness that today are not considered specific for COVID-19. This includes, among other things, loss of smell, burning of the skin of the back, pain in the chest, severe weakness even for one day. All this is not reliable signs of coronavirus infection..
If you have any doubts about whether you have a coronavirus infection or have had it before, get tested for IgG and IgM antibodies to coronavirus… Better yet, check with your healthcare professional before testing.
The presence of class G antibodies to COVID-19
The most important and most reliable sign is the presence of a significant amount of class G antibodies to COVID-19 in your blood 10-12 days after the onset of the disease. Antibodies of class G (or IgG for short) are memory antibodies that indicate that our immunity is familiar with infection. In patients who have undergone coronavirus infection, antibodies of this class appear by 10-12 days from the onset of the disease, therefore, an antibody test is useless at the very beginning of the disease.
Lack of class M antibodies to COVID-19
An equally important sign is the absence of significant amounts of class M antibodies to COVID-19 in your blood after 14-21 days from the onset of the disease. Class M antibodies (or IgM for short) are proteins that the immune system uses to attack a pathogen it has recently recognized. Thus, high IgM to coronavirus is an indication that you are still sick or have just begun to recover.
Only the presence of high IgG values alone will indicate that you are guaranteed to have had a coronavirus infection.
Positive smear
A relatively important sign is that you have a positive smear for COVID-19, which was taken in the early days of an acute respiratory illness. In fact, this symptom is considered relatively important because the accuracy of smears is low, and they give both false positive (indicate an infection when there is no infection) or false negative (indicate that there is no infection, although in fact there is one) results. Therefore, until recently, patients underwent several smears in a row, and with a stable positive result, it was possible to conclude that there really is a coronavirus infection. Currently, patients are recommended to donate antibodies of class M and G on the 10-12th day of illness.
You have had pneumonia (doubtful sign)
You have had pneumonia, confirmed by X-ray or CT, but have negative smears. Until recently, it was believed that the coronavirus only causes bilateral pneumonia, but it turned out that it can also cause unilateral pneumonia. Some patients believe that they have had coronavirus, only on the basis of X-ray or CT data, but the same antibody test is needed to make a diagnosis.
If at least 12 days have passed since the onset of your illness, take an antibody test, and you will know for sure if your pneumonia was coronavirus. But do not be surprised if the antibodies are negative: there are a lot of pneumonia pathogens, and these are not always viruses.