A negative COVID-19 test means the test did not detect the virus, but this doesn't rule out that you could have an infection. If you used an antigen test, follow FDA recommendations for repeat testing. If you have symptoms: You may have COVID-19 but tested before the virus was detectable.
Antibodies and other viruses
Keep in mind that if a person tests negative for COVID-19 but still exhibits symptoms, they may have another virus like the flu or a respiratory syncytial virus (RSV), which a COVID-19 test would not pick up.
A negative result from a COVID-19 rapid test is usually enough to ease worries, but one test isn't enough to rule it out. One negative result could mean that you don't have a contagious amount of the virus at the time of testing, even if you do have COVID-19 already, Adalja said.
If you have symptoms of COVID-19 and you get a negative antigen or PCR test result, you should self-isolate until you have not had any symptoms for 48 hours. Your negative PCR or antigen test result does not mean that you've never had COVID-19. It just means that the virus was not found on the sample that was taken.
Some people can test positive for COVID-19 for weeks or even months on PCR tests, but there is good news: people are not likely to be contagious for that long from a single infection, even if they test positive, and therefore are unlikely to transmit the virus to others.
People with moderate or severe COVID-19 should isolate through at least day 10. Those with severe COVID-19 may remain infectious beyond 10 days and may need to extend isolation for up to 20 days.
You are considered contagious from two days before your symptoms begin until 10 days after your symptoms began. If you have no symptoms, you are considered contagious beginning two days before your test sample was collected and until 10 days after your test sample was collected.
Antigen tests produce results quickly (within minutes), and most can be used at the POC or at home. Most self-tests, or at-home tests, are antigen tests. Antigen tests are better at detecting a SARS-CoV-2 infection when someone has COVID-19 symptoms compared to if they do not.
However, at-home COVID-19 antigen tests are generally expected to detect the SARS-CoV-2 virus at least 80% of the time when someone is infected.
If your result is negative, you will see one line next to C. If you have a void result, you will see a line next to T. This means the test is void and hasn't worked.
On June 30, the Centers for Disease Control and Prevention added three symptoms to its COVID-19 list: Congestion/stuffy nose, nausea and diarrhea. Those three new conditions now join other symptoms identified by the CDC: Fever.
We conducted an in-depth case review of five patients with initially negative RT-PCR results among the 145 patients with COVID-19 confirmed by RT-PCR testing (Table 1). This false-negative rate of 3.45% is comparable to that reported in a systematic review, which found a false-negative RT-PCR rate of 2–29% [3].
A test cannot tell how contagious you are.
Testing positive for COVID-19 means you have pieces of the virus in your body.
The symptoms are very similar to symptoms of other illnesses, such as colds and flu. Most people feel better within a few days or weeks of their first COVID-19 symptoms and make a full recovery within 12 weeks. For some people, it can be a more serious illness and their symptoms can last longer.
Conclusions: This systematic review showed that up to 58% of COVID-19 patients may have initial false-negative RT-PCR results, suggesting the need to implement a correct diagnostic strategy to correctly identify suspected cases, thereby reducing false-negative results and decreasing the disease burden among the ...
For rapid antigen tests, this includes a clinical sensitivity of at least 80% (for specimens collected within 7 days of symptom onset) and a clinical specificity of at least 98%.
The PCR test for COVID-19 works by detecting genetic material from SARS-CoV-2, the virus that causes COVID-19. The genetic material from SARS-CoV-2 cannot be confused with the genetic material from other viruses, so the COVID-19 diagnostic test is highly specific. This means it almost never gives a false positive.
Many people who are infected have more mild symptoms like a scratchy throat, stuffy or runny nose, occasional mild cough, fatigue, and no fever. Some people have no symptoms at all, but they can still spread the disease.” Fever seems to be one of the more common early markers of COVID-19, Kline noted.
Testing can be helpful even when you don't have symptoms or a recent exposure to COVID-19, such as before an event or visiting someone. Test as close to the time of the event as possible (at least within 1-2 days) to help you make informed decisions about your health and your risk of spreading COVID-19 to others.
You should get a COVID-19 test if: You have new symptoms such as fatigue, headache, body/muscle aches, cough, fever, sore throat, and/or congestion. You have symptoms and are at high risk for severe illness because of other medical conditions, age, or have a compromised immune system.
Clinical laboratory staff and health care providers should be aware that COVID-19 diagnostic tests are generally designed to detect all known variants.
In high-risk settings, they may be considered infectious from 72 hours before symptoms start. People with mild illness are generally considered recovered after 7 days if they have been asymptomatic or have not developed any new symptoms during this time.
When do omicron subvariant symptoms start? The time it takes for an infected person to develop symptoms after an exposure is shorter for the omicron variant than for previous variants — from a full week down to as little as three days or less, according to the Centers for Disease Control and Prevention.
Your infectiousness is highest 1 day before the start of your symptoms and begins to wane about a week later for most people. The Omicron variant has a shorter incubation period, compared to other variants. For the Omicron variant, the incubation period is 1 to 4 days.