Novel Coronavirus COVID-19
 

COVID-19 Rapid Antigen Tests (RATs)


COVID-19 rapid antigen tests (RATs) detect proteins on the surface of the COVID-19 virus. They can also be used to detect proteins from inside of the virus. These proteins are released after breaking up the virus using a simple soap solution, which is provided with the test.

There are situations where using a RAT is helpful, but it is important to remember that RATs only reflect your health status at the time of the test. RATs are easy to use and give results quickly. However, the PCR test performed at a laboratory is still the “gold standard” test because it is more sensitive.

There are certain groups that public health will recommend a PCR test rather than a RAT. As well, public health may recommend a confirmation PCR test for some individuals who have a positive RAT. For more information on testing recommendations, visit:


A self-collected nasal swab sample is tested for the presence of the virus that causes COVID-19. RATs can be used in the home, workplace or elsewhere by someone who is not a trained health care professional. Most self-tests produce a result within 10 to 20 minutes and results are interpreted by the individual. It is very important to read the instructions carefully for the specific RAT you are using because there are small differences between different types of RATs.


RATs may be used for children. Most of the RATs authorized for use by Health Canada are for use on individuals two years and older. However, doing a swab on a young child or a child who is unable to stay still can be challenging and caution should be taken. You can also visit a health care professional or attend a provincial test site (https://www.manitoba.ca/covid19/testing/locations.html) if it is recommended that your child be tested. For children, RATs should always be done by an adult. For youth, they should be supervised by an adult. See the instructions provided with the test for any safety instructions to follow if using the test on a child.


Self-testing or at-home testing may not be suitable for everyone. Some examples of when a self-test or at home test is not suitable include:

  • individuals who are unable to follow directions - this may be due to their age (chronological or developmental) or if there is a language barrier
  • individuals with a health condition that makes them or others assisting them unable to perform a nose swab, do the test, or read the result - e.g., a neurological disease that makes it hard for them to self-swab
  • individuals who are unable to safely perform a self-swab or it is unsafe for someone at home to swab them - e.g., difficulties holding their head back or difficulties holding their head still

Individuals who are symptomatic and who are unable to take a self-test should go to a provincial test site. For more information on testing locations, see https://www.manitoba.ca/covid19/testing/locations.html or call Health Links - Info SantÚ at 204-788-8200 or (toll-free) at 1-888-315-9257.


It is very important to follow the steps in the instructions provided with the test you use. There are small differences between different types of RATs, so do not assume the steps are the same. Pay particular attention to how to collect the best sample and the incubation time (the time you need to wait until you read the results). Not following the steps properly, including not waiting long enough or waiting too long to read the test result, can lead to an incorrect result. Note: a faint line is still a positive.

All tests are for single-use only which means you can only use each test ONCE and then it must be thrown away in the garbage. Do not use a test (including the swab) more than once or attempt to use one test on different people. Also, if the test has expired, do not use it. If you received RATs from a provincial test site, be sure to use them shortly after you have received them to ensure they remain accurate.


RATs can be used if you have COVID-19 symptoms. For more information on symptoms of COVID-19, see https://www.manitoba.ca/covid19/fundamentals/symptoms.html.

For most situations, you do not need a confirmatory PCR test if your RAT result is positive. Public health recommends confirmatory PCR only for a few situations. For more information, visit https://www.manitoba.ca/covid19/testing/testing-eligibility.html.

Positive RAT
If your RAT result is positive, you need to consider yourself as having COVID-19 and should isolate and notify your close contacts.

In general, you should isolate for a minimum of 10 days from our test and until you do not have fever and your other symptoms have been improving over the past 24 hours. There are different isolation periods for people who have been vaccinated and people who have not been vaccinated. Visit:

Treatment for COVID-19 is now available for people at higher risk of severe disease. If you have a positive RAT please visit https://manitoba.ca/covid19/treatment/index.html for more information and to find out if you are eligible, or call Health Links - Info SantÚ at 204-788-8200 or (toll-free) at 1-888-315-9257.

Negative RAT
If your RAT result is negative, you may still have COVID-19. You could still be contagious and the test is simply not picking it up. It can take some time for the amount of proteins to increase high enough to be detectable by RAT.

If you used a RAT because you have symptoms, it is recommended you repeat the test again after 24 hours to see if it is still negative. If the repeat test is negative and you have access to another RAT, it is recommended you repeat the test again after another 24 hours. See below for more information on how long you should stay home and isolate.

Invalid Test
If your RAT result is invalid (doesn’t match negative or positive), repeat the test.


Even with a negative RAT, it is important to continue following public health guidance including staying home if you are sick, washing your hands frequently, maintaining physical distancing and wearing a mask indoors and when required by public health order. If your symptoms worsen you should speak with your health care provider or call Health Links - Info SantÚ at 204-788-8200 or (toll-free) at 1-888-315-9257.

  • If you have symptoms, but have not been exposed to COVID-19 through travel or contact with a case and have a negative RAT: You should continue to stay home and isolate until you do not have fever and your other symptoms have been improving over the past 24 hours. It is important to continue following the public health fundamentals even after you have recovered.
  • If you have symptoms, have been exposed to a case and have a negative RAT: You must continue to self-isolate (quarantine) for the entire 10 days from your last exposure and until you do not have fever and your other symptoms have been improving over the past 24 hours. If you are exempt from self-isolation (quarantine) as a close contact, you should continue to stay home and isolate until you do not have fever and your other symptoms have been improving over the past 24 hours.
  • If you have symptoms, have traveled outside of Manitoba and have a negative RAT: You must continue to self-isolate (quarantine) for the entire 14 days from your date of travel and until you do not have fever and your other symptoms have been improving over the past 24 hours. If you are exempt from self-isolation (quarantine) due to travel, you should continue to stay home and isolate until you do not have fever and your other symptoms have been improving over the past 24 hours.

In general, public health does not recommend testing if you do not have symptoms. Most importantly, follow self-isolation (quarantine) requirements if you are a close contact and public health fundamentals. For more information on what to do if you have been exposed to COVID-19 and recommendations for your household members see the Self-Isolation (Quarantine) for Asymptomatic Returning Travellers and Contacts of Cases fact sheet at: https://www.manitoba.ca/covid19/updates/resources.html#collapse3.

RATs can be used if an individual is asymptomatic and had a high risk exposure (e.g., household close contact to a case). Symptoms of COVID-19 may take up to 14 days to appear after exposure to the virus, but most individuals develop symptoms within the first week. If you have no symptoms, are a household member of a case and you are exempt from self-isolation (quarantine), public health recommends that you use up to five RATs in the first seven days after your exposure. You could either use the RATs daily or every other day. Since the test is less sensitive than PCR, testing on several days will improve the accuracy of the test. However, it is important to remember that a negative RAT does not rule out COVID-19. You should continue to follow public health guidance even after a negative test. If you are required to self-isolate (quarantine), negative RATs do not change how long you must self-isolate (quarantine).

If you develop symptoms after a recent negative RAT, do not assume that your negative test means you don’t have COVID-19. You should be tested again after developing symptoms.

If your RAT result is positive, you need to consider yourself as having COVID-19 and should isolate and notify your close contacts. For most situations, you do not need a confirmatory PCR test if your RAT result is positive. Public health recommends confirmatory PCR only for a few situations. For more information, visit: https://www.manitoba.ca/covid19/testing/testing-eligibility.html.

In general, you should isolate for a minimum of 10 days from your test and until you do not have fever and your other symptoms have been improving over the past 24 hours. There are different isolation periods for people who have been vaccinated and people who have not been vaccinated. See the Isolation for Individuals with Symptoms and/or Waiting for COVID-19 Test Results factsheet (https://www.manitoba.ca/covid19/updates/resources.html#collapse2) for more information including how long you should isolate, how to isolate, and recommendations for your household members. Information on how to notify your contacts can be found at https://www.manitoba.ca/covid19/testing/monitoring/index.html.


RATs can be used if an individual is asymptomatic, but it is important to remember that the result only reflect your health status at the time of the test and a negative test does not rule out COVID-19. Even with a negative RAT, it is important to continue following public health guidance including checking yourself for symptoms, staying home if you are sick, washing your hands frequently, maintaining physical distancing, and wearing a mask indoors and when required by public health order.

If you develop symptoms after a recent negative RAT, do not assume that your negative test means you don’t have COVID-19. You should be tested again after developing symptoms.

If your RAT result is positive, you need to consider yourself as having COVID-19 and should isolate and notify your close contacts. For most situations, you do not need a confirmatory PCR test if your RAT result is positive. Public health recommends confirmatory PCR only for a few situations. For more information, visit: https://www.manitoba.ca/covid19/testing/testing-eligibility.html.

In general, you should isolate for a minimum of 10 days from your test and until you do not have fever and your other symptoms have been improving over the past 24 hours. There are different isolation periods for people who have been vaccinated and people who have not been vaccinated. See the Isolation for Individuals with Symptoms and/or Waiting for COVID-19 Test Results factsheet (https://www.manitoba.ca/covid19/updates/resources.html#collapse2) for more information including how long you should isolate, how to isolate, and recommendations for your household members. Information on how to notify your contacts can be found at https://www.manitoba.ca/covid19/testing/monitoring/index.html.


Unlike PCRs, which can continue to be positive for several months after you have recovered, RATs should not be positive if you have recovered. This is because RATs are less sensitive than PCR tests and are much less likely to pick up an old infection. If you have recovered from COVID-19 and have a positive RAT, you need to consider yourself as having a new COVID-19 infection and should isolate and notify your close contacts.

See the Isolation for Individuals with Symptoms and/or Waiting for COVID-19 Test Results factsheet (https://www.manitoba.ca/covid19/updates/resources.html#collapse2) for more information including how long you should isolate, how to isolate, and recommendations for your household members. Information on how to notify your contacts can be found at https://www.manitoba.ca/covid19/testing/monitoring/index.html.




Resources

COVID-19 Rapid Antigen Tests (RATs) - Public Health Factsheet