PSYchology
We have prepared a selection of up-to-date information about coronavirus tests in Russia and in the world. How and where to do the test for a fee and for free, what doctors and patients tell about the features of diagnostics, expert answers to the most pressing questions – look for all this in our article

Today, two dozen vaccines are registered in the world, including four vaccines in our country. They help create protection against infection1. But, unfortunately, the third wave led to an increase in the incidence due to the arrival of a new, Indian strain, which, according to scientists, is more contagious than the previous ones. And in order to identify the infection, isolate the sick person in a timely manner and begin active treatment, testing is necessary, which quickly detects the presence of the virus in the body. It is equally important to determine the presence of antibodies – this helps to establish the phase of the disease or confirm a previous illness or the presence of immunity after vaccination. What diagnostic methods are used today?

Types of tests for COVID-19

To date, various licensed laboratories are performing several test options for diagnosing COVID-19. Each of the studies has its own goals and has its own indications.

All analysis options are divided into two large groups:

  • direct – direct detection of the pathogen;
  • indirect – fixing the response of the immune system to the penetration of the virus.

Direct methods include molecular diagnostics and the determination of viral antigens (the so-called rapid tests). Indirect tests include testing for the detection of antibodies.2.

PCR diagnostics of coronavirus infection

Refers to direct molecular methods. The test is designed to confirm active COVID-19 and is given to people who have symptoms of a respiratory infection or who have been in contact with infected people. For the study, a swab is taken from the nasopharyngeal mucosa, which is examined by PCR for the presence of genetic material (RNA) of the coronavirus in the biomaterial.

If the PCR test is negative, then at the time of sampling the person was not infected. In order to confirm or exclude infection, it is recommended to repeat the test 10 days after the first smear. Upon discharge from the hospital, you also need to obtain two negative PCR tests with an interval of at least one day3.

Modern test systems for direct diagnosis are quite accurate. But it is possible to get a false negative result, even if you have symptoms similar to COVID-19. Key reasons for these results:

  • low viral load (there are few viral particles in the material);
  • late stage of the disease – the virus has already descended from the respiratory tract;
  • violation of the rules for the collection of materials.

Rapid tests for the detection of viral antigens

Viral antigens are special proteins that are part of the virus itself and are actively recognized by the immune system. Testing for their detection is another way to diagnose COVID-19 for those who have been in contact with patients. In the absence of viral antigens, a conclusion is made about the absence of infection. But, as with other tests, the results are relevant at the time the analysis was taken and do not guarantee that the person did not become infected later, after the test was completed. Testing is quite quick and simple, it can be done during a doctor’s appointment. But there is also a limitation on its sensitivity.4.

Antibody tests (IgM and IgG)

This is an indirect technique that determines the response of the immune system to infection in a blood test.

IgM and IgG are determined – antibodies that are synthesized in the human body after contact with viruses.

IgM – acute phase immunoglobulins, which begin to form from 3-5 days after the introduction of the virus and indicate an acute infection.

IgG appear as the disease is overcome, usually from 10-14 days from the onset of infection and persist after it for quite a long time. Their presence indicates the transferred disease and the formation of immunity. How long antibodies remain in the body is still unknown, scientists are still studying a new infection. While there is evidence that they are stored up to six months.

An IgG test is helpful in assessing herd immunity to COVID-19 and can be taken by anyone who wants to test their immune status for a new disease but has no symptoms of the disease and has not been in contact with a sick person. These tests help determine the number of people who have been ill. Some tests also determine the antibody titer – a quantitative reflection of the volume of immunoglobulins.

Antibodies can also be assessed by rapid tests, they determine the presence of antibodies in the blood. Such tests are easy to perform, can be used at a doctor’s appointment, but are less sensitive than traditional tests.5.

Free tests for coronavirus in Russia

From the very beginning of the epidemic, free testing for coronavirus has been mandatory for five categories of citizens. The list is posted on the websites of the Ministry of Health and Rospotrebnadzor (it is repeated to us so often that everyone has already memorized it). These are those who returned from abroad with signs of respiratory diseases and who were in contact with the infected. Elderly (over 65) with respiratory symptoms. Physicians at risk of exposure to COVID-2019 in the workplace. And also to everyone who is in institutions of permanent residence (special institutions of a closed type, cadet corps, boarding schools, institutions of the Federal Penitentiary Service) with symptoms of a respiratory disease.

At the moment, analyzes are done by any category of citizens, if the decision on the analysis was made by a doctor.

Popular questions and answers

Who and how do they take a free test for covid today – which ones are used?

Scientists are lamenting that it was necessary to involve private laboratories in the production of test systems for COVID-19 and diagnosis back in January, when the nucleotide sequence of the virus became known. Finally, this opportunity was provided.

At the end of March, two private networks of laboratories began conducting tests in Moscow, St. Petersburg and a number of large Russian cities. Anyone can get tested for coronavirus. The results are ready in 2 days (PCR testing method). If infection with COVID-19 is confirmed, the information will be transferred to Rospotrebnadzor, and from there specialists will be sent to take the analysis for re-confirmation in the state laboratory.

How are things going with covid tests in the world?

Italy

The survey rate here is the highest in Europe. At first, only people with obvious symptoms of SARS (high fever, cough, shortness of breath) and those who had contact with the sick were tested. Now the diagnosis for coronavirus has been mass-produced. The test is prescribed by a doctor – smears are taken to the laboratory, which are available in each region, and the result is ready within 4-6 hours. If necessary, the data is rechecked by the Italian Institute of Health. Tests for the population are free of charge, the service is included in the compulsory health insurance.

Germany

The Robert Koch Institute (German Federal Institute for the Study of Infectious Diseases and Intolerable Diseases, located in Berlin) clarifies and comments: tests in the country are ordered if there are symptoms of a respiratory disease (shortness of breath, fever, etc.). As well as those who have been in contact with a patient who was diagnosed with COVID-19 in the laboratory, and people whose work is associated with a high risk of infection (doctors, volunteers). The analysis is done at the expense of insurance.

– On the outskirts of our town in early March, a tent field clinic was built, where tests are carried out. It’s called the “feverish outpatient clinic” (Fieberambulanz), says Elena, a doctor from Koblenz. – The scheme is as follows: a person calls an outpatient clinic (praxis), where they ask about symptoms and contacts, and then they are sent for analysis. Some home doctors can take tests themselves, but only if they have special protective suits and respirators. Test results are sent by mail. If necessary, repeat the test.

Greece

Tests are carried out by both private and public clinics. In the state, they do it for free, but only for people with obvious symptoms (fever, cough, shortness of breath), medical staff, the elderly (over 70), diabetics, people with diseases of the lungs and cardiovascular system. The smears are sent to the laboratory, the result is known in 24-72 hours. An analysis in a private clinic costs from 150 euros and more. If the test result is positive, re-analysis will be done free of charge at the state laboratory. Stationary (7 of these) and mobile (about 500) laboratories operate throughout the country.

How accurate are the texts on coronavirus that are currently being used, and can they be trusted?

Each test has declared characteristics: sensitivity and specificity – they are indicated on the package. And in order for the result to be as reliable as possible, it is important to technically correctly collect biological material. For PCR tests, it is important that the sample for the test is taken from the nasopharyngeal mucosa, because the virus multiplies in it. If you move a wand in your nose or throat, the test will be negative, because there are no cells in the nose or mouth where the virus multiplies – it lives in the upper respiratory tract. Unfortunately, the biomaterial is often taken incorrectly from us, and therefore the results turn out to be incorrect.

Which test is the most accurate? What is better to take to confirm the infection?

The main test for detecting covid in the acute phase – PCR diagnostics – is used mainly in people with symptoms of colds (ARVI), or in people who have been in contact with a patient with covid-19.

To whom and how can a paid test for covid be done today, can they be taken at home or only in a clinic?

Anyone, if there is a need for it. The test can be done in a private clinic, specialized laboratories, or at home.

Which test is the most accurate? What is better to take to confirm the infection?

To confirm the infection, a PCR or antigen test is done.

What test will help determine the immunity after vaccination?

Blood test for IgG to covid (spike protein).

What level of antibodies is guaranteed to protect against infection?

There is no information about specific figures when we can talk about guaranteed protection.

Sources:

  1. All about vaccination against COVID-19. https://vaccine.stopcoronavirus.rf2
  2. Rospotrebnadzor, 08.06.2020/19/14612. About the types of research for a new coronavirus infection COVID-XNUMX. https://www.rospotrebnadzor.ru/region/rss/rss.php?ELEMENT_ID=XNUMX
  3. Tamara Amvrosyeva, Natalia Poklonskaya COVID-19: LABORATORY DIAGNOSIS // Science and Innovations. 2020. No. 7 (209). https://cyberleninka.ru/article/n/covid-19-laboratornaya-diagnostika
  4. N. A. Mayansky Immunity to covid-19 and issues of screening studies of antibodies to SARS-CoV-2 // Vestnik RSMU. 2020. №3. https://cyberleninka.ru/article/n/immunitet-k-covid-19-i-voprosy-provedeniya-skriningovyh-issledovaniy-antitel-k-sars-cov-2
  5. Chernichuk O.V., Chernova O.O. LABORATORY DIAGNOSTICS OF THE NEW CORONAVIRUS INFECTION COVID-19 // Healthcare of Yugra: experience and innovations. 2021. №2. https://cyberleninka.ru/article/n/laboratornaya-diagnostika-novoy-koronavirusnoy-infektsii-covid-19.

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