What do COVID-19 PCR test results mean?
A positive test result means that it's likely that you have an infection with SARS-CoV-2. This could be due to asymptomatic infection, but if you have symptoms, then this infection is called COVID-19. Most people have mild illness and can recover safely at home without medical care. Contact your healthcare provider if your symptoms get worse or if you have questions or concerns.
A negative test result means you probably didn't have an infection with SARS-CoV-2 at the time your specimen was collected. However, it's possible to have COVID-19 but not have the virus detected by the test. For example, this may happen if you recently became infected but you don’t have symptoms yet — or it could happen if you've had COVID-19 for more than a week before being tested. A negative test doesn’t mean you are safe for any length of time: You can be exposed to COVID-19 after your test, get infected and spread the SARS-Cov-2 virus to others.
If your test is positive, talk with your healthcare provider, stay home and separate yourself from others. If your test is negative, continue to take steps to protect yourself and others from getting COVID-19. Read more about what to do if you test positive and ways to prevent getting infected with COVID-19.
How long does it take to get coronavirus test results?
You should receive your test results as early as 24 hours after sample collection, but sometimes it can take a few days, depending on how long it takes the sample to reach the laboratory.
How long do you test positive after having had COVID-19?
Because the PCR test is so sensitive, it can detect very small amounts of virus material. This means that the test can continue to detect fragments of SARS-CoV-2 virus even after you’ve recovered from COVID-19 and are no longer contagious. So you may continue to test positive if you've had COVID-19 in the distant past, even though you can’t spread the SARS-CoV-2 virus to others.
Prolonged infection in immunocompromised individuals can occur where they shed infectious virus for months. Also, healthy people can become reinfected. If you test positive for SARS-CoV-2 but you think you might have already recovered from COVID-19, please discuss with a healthcare provider.
FAQs
The nose swab PCR test for COVID-19 is an accurate and reliable test for diagnosing COVID-19. A positive test means you likely have COVID-19. A negative test means you probably did not have COVID-19 at the time of the test.
What is a PCR test and how is it done? ›
The PCR test takes a sample of ribonucleic acid (RNA) and “amplifies” it with the help of lab technologies. Amplifying RNA helps to make even small traces of the COVID-19 virus visible in the test sample. Even if you have a small trace of the virus in your system, the PCR test will detect it.
How to read COVID-19 test results? ›
You might see a line next to the letter C and a line next to the letter T. This means you are positive. You have COVID-19. Only 1 line next to the letter T • No lines at all If there is no line or colour next to the letter T your test is negative.
How does a positive COVID test look? ›
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.
What do the results on a Covid test mean? ›
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 test positive, you and your. household should self-isolate following.
How does PCR work step by step? ›
PCR is based on three simple steps required for any DNA synthesis reaction: (1) denaturation of the template into single strands; (2) annealing of primers to each original strand for new strand synthesis; and (3) extension of the new DNA strands from the primers.
What is the meaning of PCR? ›
Polymerase Chain Reaction (PCR)
Polymerase chain reaction (abbreviated PCR) is a laboratory technique for rapidly producing (amplifying) millions to billions of copies of a specific segment of DNA, which can then be studied in greater detail.
What are the C and T lines on a COVID test? ›
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.
What does it mean when PCR test is positive? ›
What do COVID-19 PCR test results mean? A positive test result means that it's likely that you have an infection with SARS-CoV-2. This could be due to asymptomatic infection, but if you have symptoms, then this infection is called COVID-19.
What if the C line is faint? ›
“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.
Positive: The presence of the test line (T) and the control line (C) within the result window, regardless of which line appears first, indicating a positive result. The presence of any test line (T), no matter how faint, indicates a positive result.
Does a very faint line mean COVID? ›
Any line on a COVID-19 antigen test indicates a positive test, regardless of its intensity. Factors that might influence the line's appearance include your viral load, whether or not you have symptoms, and not using the test kit correctly.
How to get rid of COVID fast? ›
Many people with COVID-19 get better with rest, fluids and treatment for their symptoms. Medicine you can get without a prescription can help. Some examples are: Fever reducers.
Does a darker line mean more COVID? ›
If you get a quick, dark line, it's probably going to be pretty clear to you that your COVID test is positive. However, Mina emphasized a slow-appearing faint line on a test or even one that's sort of blurry or fuzzy can still mean you have high levels of virus in your body.
How to read a COVID test at home? ›
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.
What are the current COVID symptoms? ›
Symptoms of COVID-19
a new, continuous cough – this means coughing a lot for more than an hour, or 3 or more coughing episodes in 24 hours. a loss or change to your sense of smell or taste. shortness of breath. feeling tired or exhausted.
What diseases can PCR detect? ›
Qualitative PCR Testing
- Acinetobacter baumannii.
- Aspergillosis (e.g., MycoDART Dual Amplification Real-Time PCR Aspergillus diagnostic panel)
- Astrovirus.
- Autoimmune lymphoproliferative syndrome.
- Bacteroides spp. (B. ...
- Blastomycosis.
- Caliciviruses (noroviruses and sapoviruses)
- Campylobacteriosis (Campylobacter infection)
The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed study.
When is PCR used? ›
In PCR, the reaction is repeatedly cycled through a series of temperature changes, which allow many copies of the target region to be produced. PCR has many research and practical applications. It is routinely used in DNA cloning, medical diagnostics, and forensic analysis of DNA.
What is the cycle of the PCR? ›
PCR (Polymerase Chain Reaction) amplifies DNA and involves a series of temperature cycles critical for amplifying the DNA target. The cycling process is divided into three main stages: denaturation, annealing, and extension. These three stages are repeated for 20-40 cycles, doubling the targeted DNA amount.
