Currently, there are various methods for COVID-19 testing. For example, the Rapid Antigen Test offers convenience and speed, available for purchase at pharmacies at a cost of a few hundred baht, with results in 15-30 minutes. Another method is the RT-PCR test, which provides higher accuracy but takes longer to get results. COVID-19 testing is recommended for individuals in high-risk groups, those with close contact with confirmed cases, or those exhibiting symptoms indicative of COVID-19.
What is an “Antigen Test Kit” (ATK)?
A Rapid Antigen Test is a simple method for detecting COVID-19 before undergoing confirmatory laboratory testing. It involves collecting samples from the nose or saliva and provides results within 15-30 minutes. This test is suitable for individuals with symptoms who have been exposed to high-risk situations, helping to separate themselves from others and seek treatment if necessary. For those who have been in high-risk contact but are asymptomatic, this preliminary test may be used, though it has about a 90% accuracy rate. The test is most effective when performed 5-14 days after exposure, as it may not detect the virus if done earlier.
There are two types of rapid test kits:
1. Rapid Antigen Test: This method detects the virus by collecting samples from the nasal cavity.
2. Rapid Antibody Test: This method detects antibodies in the blood, collected via a blood draw.
What You Should Know Before Using an “Antigen Test Kit”
The Rapid Test kits approved by the Ministry of Public Health for self-testing are “Rapid Antigen Test” kits. These tests are intended for single use per person only! The kits must be evaluated and registered with the FDA. They should be purchased from medical facilities or pharmacies with licensed pharmacists to receive correct usage instructions. As of August 26, 2021, there are 45 brands registered with the FDA for Home Use, allowing for self-testing.
You can check the list of approved brands at the following link: https://www.fda.moph.go.th/sites/Medical/SitePages/test_kit_covid19.aspx
How to Use the “Antigen Test Kit”
Clean the surface where you will place the test kit thoroughly using disinfectant alcohol. Wash your hands well or wear gloves to maintain cleanliness when handling the equipment.
How to Collect a Sample
Follow the instructions provided with the test kit carefully, as each kit may have different details. After collecting the sample and preparing the equipment according to the user manual, insert the swab into the test solution tube and rotate it at least 5 times or for 15 seconds. Then, squeeze the swab to remove excess liquid from the tube, avoiding direct contact with the swab or the collected solution. Dispose of the swab in a sealed bag. Next, add the specified number of drops of the solution to the test device as indicated in the test kit instructions. Wait for 15-30 minutes for the results, according to the test kit documentation.
How to Read the Test Results
After waiting for 15-30 minutes as indicated in the test kit instructions, read the results. The letter “C” indicates the control line, and the letter “T” indicates the test line. The results should be interpreted as follows:
If there is one line at the letter “C,” it means the test result is negative, or “not infected.”
If there are two lines at both the letters “C” and “T,” it means the test result is positive, or “infected.”
If there is no line at the letter “C,” such as only a line at “T” or no lines at all, it means the test is invalid. You should repeat the test, following the instructions in the test kit documentation carefully.
What to Do After Receiving the Results
In Case of a “Positive Result”
Contact a nearby health service, such as a local clinic, nearby hospital, or district health office, to receive guidance on entering the self-isolation and treatment system. Inform close contacts to assess their risk and arrange for further testing.
In Case of a “Negative Result”
If you are at high risk, you should repeat the test in 5-8 days or when symptoms appear. A single negative test does not conclusively rule out infection. Therefore, you should isolate yourself from others while waiting for the follow-up test.
References
Office of the Food and Drug Administration: www.doh.hpc.go.th