About SARS-CoV-2 Rapid Antigen Test
- Intended for testing symptomatic and asymptomatic individuals
- Rapid detection of individuals with SARS-CoV-2 infection
- Results are completed within 30 min
ABOUT THE TEST
The SARS-CoV-2 Rapid Antigen Test that we use in our hospital in the diagnosis of COVID-19 is on a common list of rapid antigen tests that are mutually recognized by the Member States of the European Union.
The SARS-CoV-2 rapid antigen test is an extremely valuable diagnostic test with high specificity (99.68%) and belongs to the family of tests that are performed in direct contact with the patient and for which results are obtained shortly after testing (Point of care tests). ). In general, tests which detect antigens have a slightly lower sensitivity (96.52%) compared to molecular tests. Therefore, negative antigen test results has to be interpreted in the context of others factors, including possible previous exposure to the virus, the occurrence of clinical symptoms, etc. If the result is doubtful, a molecular diagnosis for the presence of SARS-CoV-2 virus can be performed within a few days.
The clinical significance of rapid antigen tests depends on the circumstances in which they are used. The best result is obtained when a person is tested in the early stages of SARS-CoV-2 virus infection when the virus concentration is the highest. They are also informative for people who have been in contact with a confirmed case of COVID-19 as well as for testing in high-risk living environments (homes for the elderly, pupils and students) when repeated tests can quickly detect people with SARS-CoV-2 infection and thus prevent the spread of the virus.
HOW AND WHEN TO BE TESTED
HOW IS TESTING PERFORMED?
Testing is performed from the nasopharyngeal or nasal swab.
WHERE TO TEST?
St. Catherine Specialty Hospital, Trpinjska 7, Zagreb.
INTERPRETATION OF RESULTS
The new corona virus SARS-CoV-2 belongs to the Coronaviridae family. The nucleocapsid protein (N-antigen) is one of the four SARS-CoV-2 structural proteins, and its primary role is to “pack” RNA viral genome within the viral envelope into a ribonucleoprotein (RNP) complex, known as a capsid.
The concentration of SARS-CoV-2 N antigen on the mucosa rapidly increase several days after infection, reaches a maximum around day 15 and in the next 10-15 days decreases below the level of detection.
The SARS-CoV-2 antigen test is a rapid immunochromatographic method intended for the qualitative detection of the specific SARS-CoV-2 N antigen. The test is performed in a health care institution from a nasopharyngeal or nasal swab and is intended for rapid detection of SARS-CoV-2 virus infection in symptomatic and asymptomatic individuals of all ages. The test has a sensitivity (proportion of infected persons correctly identified by the test) of 96.52% and a specificity (proportion of healthy persons correctly recognized by the test) of 99.68%. These results were obtained by analyzing 426 samples tested in two independent institutions.
This test detects proteins that are structural and functional parts of the virus, and we also call them antigens. Antigens are molecules that can trigger an immune response in the body. If the SARS-CoV-2 antigen is present in the sample in sufficient concentration, it will bind to specific antibodies and give a visible colored signal on the test device within 15 minutes. The obtained result is qualitative, positive or negative.