The Ministry of Health established in its "Strategy for diagnosis, surveillance and control in the transition phase of the Covid-19 pandemic" that the main objective is the early detection of all cases compatible with Covid-19 to control the transmission of the disease.
There are several types of tests, some based on the detection of genetic material (RNA) of the virus and others on the detection of antibodies (IgM or IgG) against Sars-cov-2. Some of the tests available on the market are shown below:
Detects the presence or absence of IgG and IgM antibodies in a blood sample.
It looks for the detection of genetic material (RNA) of the virus through a nasopharyngeal and / or oropharyngeal sample .
Look for the presence of IgG and IgM antibodies in a capillary blood sample.
Qualitatively determines specific IgG antibodies against the virus in a serum or plasma sample.
What test are you going to do?
The early detection of Covid-19 is carried out by performing a PCR on every suspected case of infection in the first 24 hours. Any person with a clinical picture of sudden onset acute respiratory infection that includes, among others, fever, cough or shortness of breath is considered a "suspicious case". Other less prevalent symptoms can also be considered suspicion of infection.
According to the WHO, "Quick Tests" are only recommended in exceptional situations, studies and research purposes.
The s erologías antibody or ELISA tests are currently not considered suitable for the diagnosis of acute infection disease.
What do the test results mean?
As it is based on the detection of the genetic material of the virus, it only gives us information about whether or not the person has the virus at the time the sample is taken.
Yes there is Covid-19 infection
There is no Covid-19 infection
Even if the test is negative , if there is a significant clinical suspicion, another test should be performed to ensure that the patient is not infected with the virus.
They are based on the detection of antibodies. IgM and IgG types are the body's most common response to infection. The result of the test will depend on whether or not there are antibodies and what type.
To know how to interpret the result better, we leave you the following infographics:
González Louro A. Guía clínica de Enfermedad por coronavirus 2019 (COVID-19) [Internet]. Fisterrra. 2020 [citado 22 may 2020]. Disponible en: clinicas/covid-19/
Prueba coronavirus: Diferencia entre el test rápido y el PCR [Internet]. RedacciónMédica. 2020 [citado el 22 may 2020]. Disponible en:
[Last Updated: 12/08/2020]