You want to know what types of coronavirus tests exist? We can include them in two large groups. On the one hand, those in which the samples are sent for analysis to the laboratory. And, on the other hand, the rapid tests, which give the results in just 15 minutes.
Tests that require laboratory
It is the best known Covid-19 test of all. It allows detecting if a person has the disease in an active phase, and is considered the most reliable test of all. A respiratory sample is taken, and it is analyzed in the laboratory. If detected SARS-CoV-2 RNA, the result is positive. In contrast, if the PCR test does not detect genetic material of the virus, the person does not have coronavirus.
ELISA serological analysis
The so-called ELISA serological test also requires a laboratory, and the results take about 48 hours, depending on the workload. The sample is taken with a standard blood test. In the laboratory, an enzyme capable of causing a chemical reaction to the sample is added, thus detecting IgM and IgG antibodies, which the body generates against the coronavirus.
One of the great benefits of this test is that it has a very high sensitivity and specificity. The percentage of false negatives and false positives from ELISA test it is practically nil.
For decongest health systems, there are rapid tests, which give the results in just 15 minutes.
Antigens (Mucosa sample)
The antigen test detects virus proteins. The collection of the sample is exactly the same as in the PCR test: a sample of the mucosa is taken with a stick.
Then, instead of taking it to the laboratory, the cotton with the sample is placed in a cardboard that has some reagents. In just 15 minutes it indicates if the result is negative or positive. It works similar to a pregnancy test: two lines if the person has coronavirus and one line if they do not have the disease.
Although the positive result it is very accurate, there is some probability of a false negative. Experts point out that its reliability is not 100% proven in asymptomatic people.
The test is based on antibody detection generated by the body to deal with the virus. Therefore, this test is not used to know if a person currently has the disease, but to know if he had it before.
To carry out the test, a drop of blood from finger, and the sample is analyzed to know if the person has developed some type of immunity against Covid-19.
It is not recommended for detecting coronavirus early. It begins to be useful about two weeks after infection, about the time it takes for the body to generate antibodies. Its degree of sensitivity is between 64 and 80 percent.
These are the types of coronavirus tests that exist