If you have any of the most characteristic symptoms of Covid-19 or are simply preparing to travel or visit a family member, do not hesitate to make an appointment at Clínica Eupnea to have a Covid-19 test. We will attend to you as quickly as possible and, depending on your case, we will offer you the most reliable tests for the detection of the coronavirus: the PCR, the Rapid Antigenic Test and the Serological Tests, which constitute the Blood Analysis of the humoral immunity (where you can detect both total antibodies and detail the different types of antibodies developed), as well as the Sanguini Analysis of cellular immunity.
Below we will give you a brief description of what each of our Covid-19 tests consist of:
DIAGNOSTIC STUDIES FOR COVID-19
PCR (Polymerase Chain Reaction) is the reference test for its high reliability. It is a molecular technique that allows the detection of the genome of a virus (DNA or RNA), that is to say, it can detect the presence of the genetic material of a pathogen through a biological sample.
In the case of Covid-19, the genetic material of the coronavirus that is detected is its RNA. When the virus infects a person, it enters the cells of the nasopharynx and begins to replicate.
To perform a PCR test, a sample is taken from the patient’s nostrils using a swab. The results are obtained around 24 hours later.
This test works for the detection of Covid-19 in both symptomatic and asymptomatic patients. In addition, it can be detected days before symptoms begin and long after they disappear.
When the result is positive, the individual will be considered contagious and the virus is present until a negative result is obtained by another PCR.
The PCR does not give information about the patient’s viral load, that is to say, the result is non-quantitative for this Covid-19 test.
RAPID ANTIGEN TEST : Antigen tests are used to detect an active infection, as they identify the presence of virus proteins. The sample is processed at the same place of collection and may take a few minutes. A positive result means the virus is present and an ongoing infection is likely.
It should be performed during the first 7 days after infection, when the viral load is at its highest.
In addition, as with PCR tests, it is not able to tell if the disease has already been overcome when you take the Covid-19 test.
SEROLOGICAL ANALYSIS : This is a SARS – COV2 serological study that is carried out by means of blood extraction.
Unlike the PCR, this test detects the antibodies that the patient may have created against the SARS – COV2 infection, while the PCR detects the genome of the virus. In addition, it provides a quantitative result of the antibodies generated.
An equality with the Covid-19 PCR test is that the result is also obtained in 24 hours.
The serological test for the detection of the coronavirus consists of the detection of IgG and IgM immunoglobulins, which are proteins that can recognize, capture and block viruses so that the lymphocytes (cells of the immune system) can recognize and eliminate them. the
It is worth remembering that IgG and IgM are two types of immunoglobulins present in our blood in the form of antibodies if we have been in contact with the coronavirus.
- IgG: It is the predominant type of immunoglobulin in the body. It is found in the blood and other fluids. It is the antibody that protects against bacterial and viral infections and takes a few days to develop once the infection has passed.
- IgM: It is the immunoglobulin made by the body. It appears in the blood and its mission is to fight a new infection.
Serological tests study the response of the immune system using a sample of the patient’s blood. There are four possible outcomes:
IgG- / IgM-: In most cases, the individual is not infected with the virus. Although there is a period of, more or less, about 3 days of incubation from the infection where the anti-IgM has not yet been generated and the result is negative. Thus, the test does not rule out initial infections.
IgG- / IgM+: The individual is in the initial phase of the disease and can already be considered contagious. Confirmation by PCR or repeat analysis after 15 days is required.
IgG+ / IgM+: The individual is in an active phase of the disease or overcoming an acute phase of it and is developing antibodies. In this case, it is also convenient to undergo a PCR.
IgG+ / IgM-: The individual has passed the infection and developed antibodies against the disease. In other words, the viral replication phase is over.
It must be concluded that thanks to the analysis of IgG it has been verified that 15% of the population does not make antibodies, this may be due to the immune system using other defense pathways, such as cellular immunity. Cell-mediated immunity is a mode of immune response that is complementary to antibody immunity and results in the elimination of infected cells. In addition, they participate in long-term immunity by becoming memory cells.