Test results for COVID-19 (2024)

FAQs

Test results for COVID-19? ›

Positive test results using a viral test (NAAT, antigen or other tests) in individuals with signs or symptoms consistent with COVID-19 indicate that the person has COVID-19. A negative antigen test in individuals with signs or symptoms of COVID-19 should be repeated following FDA recommendations or confirmed by NAAT.

If the Control line (C) and the Test line (T) are visible, the test is positive. Any faint visible colored test (T) line with the control line (C) should be read as positive. You do not need to perform repeat testing if you have a positive result at any time.

If the extracted specimen contains SARS-CoV-2 antigens, a pink-to-purple T Line, along with a pink-to-purple C Line will appear on the COVID-19 Test Card indicating a positive result. If SARS-CoV-2 antigens are not present, or present at very low levels, only a pink-to-purple C Line will appear.

Read Your Results

If you see a red-colored line in the control area ("C"), your test worked correctly: If you do not see a red-colored line in the test line ("T"), your test result is negative. A negative result does not rule out COVID-19. Test again later if needed.

A positive COVID-19 test means the virus was detected and you have or recently had an infection. Take steps to prevent spreading COVID-19. Monitor your symptoms. If you have any emergency warning signs, seek emergency care immediately.

Read your result

Two lines appear. One coloured line should be in the control line region (C), and another coloured line should be in the test line region (T). Two lines, one next to C and one next to T, even faint lines, show the test is positive.

If you have 1 line by C, and 1 line by T this is called a positive result. The lines can be bright or faint. You have COVID-19. If you have 1 line by C, and no line by T this is called a negative result.

“A faint line is a positive test result,” says infectious disease expert Amesh Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security. Thomas Russo, MD, a professor and chief of infectious diseases at the University at Buffalo in New York, agrees.

Key Takeaways. At-home rapid antigen tests are widely available and can be a quick way to find out if you have COVID-19. If you get a quick, dark line on your COVID test, it's a pretty clear indicator that you're positive.

If you have an infection immediately after you are exposed to COVID-19 because it may take 2 to 5 days, and sometimes longer, for the virus to be detected by a COVID-19 antigen test. How long it takes before a test can detect the virus may vary between different COVID-19 variants and different tests.

What is a negative COVID test? ›

Negative test result

If you get a negative result, it means it's unlikely you have COVID-19. There's still a chance you could have the virus, so you should follow the advice on how to avoid catching and spreading COVID-19.

To interpret the t-test results, all you need to find on the output is the p-value for the test. To do an hypothesis test at a specific alpha (significance) level, just compare the p-value on the output (labeled as a “Sig.” value on the SPSS output) to the chosen alpha level.

Low-grade fever seems to be one of the more common early markers of COVID-19, Kline said, but not everyone will have a fever. Other potential symptoms include muscle aches, headaches, loss of appetite, and loss of taste or smell. Symptoms can appear between two and 14 days after exposure.

If a test line (T) is visible together with a control line (C), this means that the result is positive. Look carefully at the result: The test should be considered positive if two lines are visible - even if they are faint. A positive test result means it is very likely that you have COVID‑19.

If the test cassette looks like the examples below, then protein from the virus that causes COVID-19 was detected in the sample. The test is positive if there are two pink/purple lines present, one at the Control “C” line and one at the Test “T” line. Look very closely for line next to “T”. This line can be very faint.

People with mild or asymptomatic illness are usually no longer contagious after 10 days. People with moderate to severe illness or who are moderately to severely immunocompromised may remain contagious for four weeks or more after symptoms begin.

“A faint line is a positive test result,” says infectious disease expert Amesh Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security.

A positive result: Two lines on control (C) and test (T). Negative: One line on control (C).

Key Takeaways. At-home rapid antigen tests are widely available and can be a quick way to find out if you have COVID-19. If you get a quick, dark line on your COVID test, it's a pretty clear indicator that you're positive.

A Faint Line Is a Positive Test

Line intensity isn't a perfect measure of how infectious or sick you might be. Essentially, a positive result is still a positive result, no matter how it looks.