1. What is the difference between a PCR test and a rapid test?
Both PCR and antigen tests are used to help diagnose someone with an active COVID-19 infection. However, there are some important differences between the two tests.
Polymerase chain reaction, or PCR tests, are utilized to detect the presence of the virus’s genetic material. This test utilizes a technique, called polymerase chain reaction, to help amplify trace amounts of the virus DNA. This test is typically sent off to a laboratory and is able to detect low levels of a viral infection. Results are typically available within 24-72 hours.
Antigen tests, or rapid COVID tests, detect specific proteins on the surface of the coronavirus. These tests usually provide results within 15 minutes. Unlike PCR tests which magnify the amount of virus in the sample for easy detection, rapid tests require a high viral load in order to test positive, meaning someone would need to be sick with an active infection. So even if someone is infected, they may still test negative at the beginning or end of their illness when their viral load is low. Positive tests are highly specific, meaning if someone tests positive, they are most likely to be infected. With rapid tests there are a higher chance of a false negative, meaning a negative result cannot definitely rule out an active infection. If you have a negative rapid test but symptoms of coronavirus, a doctor may order a PCR test or a second rapid antigen test to confirm the result.
2. I was recently around someone who tested positive for COVID-19, what should I do?
If you have been exposed to someone with COVID-19 you should self-test, but not right away. Immediately testing after exposure will most likely result in a negative test since the viral load would be very low. Instead, wait a few days. The CDC recommends testing either when symptoms develop or if you do not have any symptoms, waiting 5 to 7 days after exposure. With the omicron variant, there have been some reports that rapid tests are still showing negative during the first day or two of symptoms. Therefore, if you have a limited number of tests, you may want to wait a day or two to take the first test.
3. When should I use a PCR test and when should I use a rapid test?
The most important factor is what is currently available in your community. Since PCR tests can detect much lower viral count, it’s recommended to utilize a PCR test a few days after exposure to COVID-19 or if symptoms start developing. If a PCR test is unavailable, you can use a rapid test. Remember, rapid tests only detect an active infection, so if you initial result is negative, it is still important to retest in a few days if symptoms have not resolved or worsened.
4. I am awaiting my PCR results, what should I do?
If you are awaiting a PCR test result due to a recent exposure or potential infection, it can be confusing on what to do. If you are having any symptoms of COVID-19, you should act as though you are positive and quarantine until test results become available. If you have been exposed, are fully vaccinated, and boosted and do NOT have symptoms, you can continue to go out while wearing a well-fitting, protective mask and try to social distance when able. Those who are not vaccinated should quarantine after a known exposure until test results are available.
5. How many at home tests should I take?
At least two if possible. At home rapid tests work best when taken over the course of a few days. If you have a limited supply, you should try and aim for a time when test results are most likely to be accurate- typically day 5 and day 7 after exposure. This is especially true if a test result is negative. By repeating a rapid test, you are allowing the virus to potentially grow more to the point that it would be detected by a rapid test. If a rapid test is negative, all it is telling you is that you are currently not positive at that point in time.
6. How often do false positives occur?
False positives on a PCR test are extremely rare and usually occur due to contamination. A false positive on a rapid test is possible but unlikely if the test was taken appropriately. If you have any symptoms and a known exposure to COVID-19, you should treat any positive test as a true positive. If you think you have a false positive from a rapid test, you can get a PCR test to confirm infection. If the PCR results as negative, then you can assume that the rapid test was a false positive.
7. Should I test myself prior to seeing people/travelling?
If you are going to visit high-risk people such as the elderly or unvaccinated population or are going to be around a lot of people, testing prior to leaving can be helpful. Sometimes you can be positive with COVID-19 and not know. Being around large groups of people when contagious can infect a large amount of people. Therefore, testing prior to travel can be beneficial and help guide your plans. A positive test result means you should isolate and cancel your travel plans. However, a negative result does not mean you can stop wearing a mask in social settings. Rapid tests can be negative before a party but can become positive over the course of an evening as your viral load increases, even if you are vaccinated and boosted. Just because you may be vaccinated and tested negative on a rapid test, you should still mask up when indoors to help reduce any potential spread of the coronavirus.
8. I tested positive for coronavirus, what should I do?
When you test positive, you should isolate yourself for a minimum of 5 days and wear a mask for five days after that (and continue to wear a mask in all situations where social distancing is not an option). If you have rapid tests available, you can retest after 5 days of isolation to see if you are still positive. If you continue to test positive, you should continue to isolate when possible. If you have COVID-19 and your rapid test is still positive at five days, you are most likely sill infectious at that time and should continue to isolate until you test negative, or your symptoms have resolved. You should then continue to always wear a mask for 5 days after isolation.
9. Can I use a PCR test to end isolation?
Since PCR tests are more sensitive to the coronavirus and can detect unviable virus after an infection, PCR tests can be positive for up to 12 weeks after infection. Therefore, it is better to use a rapid test to determine if you are still experiencing an active infection from COVID-19.
10. I recently had COVID-19, when can I get vaccinated or boosted?
Once you no longer have an active infection with COVID-19, you are able to get vaccinated or boosted. Anyone who tests positive for COVID-19 should isolate for a minimum of 5 days per the CDC. Once symptoms have resolved and/or you have a negative rapid or PCR test, you are able to get the COVID-19 vaccine.
11. What is “Flurona” and am I at risk of getting it?
Because influenza (the virus that causes the flu) and coronavirus are two different viruses, a person is able to get infected with both at the same time. While co-infection is rare, it is very possible. The number of cases of the flu were low in 2021 most likely due to increased isolation. However, this year, flu cases are increasing. Therefore, it is important to get your annual flu shot and COVID-19 vaccination in order to help reduce symptom severity should they occur.
12. I heard there are some medications coming out for COVID-19 infections?
There are currently two medications that are authorized by the FDA under an emergency use authorization. One is called Molnupiravir and the other is Paxlovid. These medications are to be utilized for the treatment of mild-to-moderate coronavirus infection who are at high risk for progression to severe COVID-19, including hospitalization or death, and for whom alternative COVID-19 treatment options authorized by the FDA are not accessible or clinically appropriate. These medications are not used to help prevent COVID-19 infection and are not to be used for pre- or post-exposure prevention. These medications are also not to be used to replace vaccinations. These medications are currently available by prescription only and limited quantities are available at this time. The medications should be taken as soon as possible after the diagnosis of a COVID-19 infection and taken for 5 days.
