Testing remains an important part in reducing the spread of COVID-19 in our communities. Below are details and information you need to know about COVID-19 testing.  (This article was originally published 6/4/21 and was updated on 12/19/22. Please look at CDC or local government websites for the latest information.)

Types of Tests

There are two main types of viral tests: NAATs and antibody tests.


NAATs (nucleic acid amplification tests) is a type of viral test that looks for current infection of COVID-19 by testing specimens from the nose or mouth. An example of a NAAT test is a PCR test (CDC, 2022).

These tests

  • Are typically most reliable for people with or without symptoms.
  • Detect the virus’ actual genetic material, which can stay in the body for up to 90 days after testing positive.
    • This test should not be used if you have tested positive in the last 90 days.

Antigen Test

Also known as a rapid diagnostic test, or “rapid test,” antigen test looks for specific proteins for COVID-19, allowing for quick results.

  • These tests are less reliable than NAATS, especially for people who are asymptomatic.
  • A single, negative antigen test does not rule out infection.
    • To best detect infection, a second negative antigen test should follow at least 48 hours after the first test.

Self-tests: Also called self-collection tests or at-home tests, these tests are antigen tests that can be done without going to a testing site. These may be used if an individual is unable to be tested by a health care provider (CDC, 2022).

  • Tests can also be purchased online, in pharmacies, and retail stores.
  • The FDA website has a list of authorized tests.
  • Similar to antigen tests, negative results do not rule out COVID-19 infection.

Choosing a COVID-19 Test (CDC, 2022)

  • If you have not had COVID-19 or tested positive in the last 90 days:
    • You may choose either a NAAT or antigen tests.
  • If you have tested positive for COVID-19 in the last 90 days:
    • If you have symptoms, use antigen tests.
    • If you do not have symptoms:
      • If your first positive test result was between 30 and 90 days of your last infection, you should use the antigen test.
      • The first positive test result was within 30 days or less of your last infection, you do not need to test.

When to Get Tested (CDC, 2022)

  • If you have symptoms.
  • If you were exposed to COVID-19 and do not have symptoms, wait at least five full days after exposure before testing.
    • Testing too early is more likely to lead to inaccurate results.
  • If you are in certain high-risk settings, where testing may be part of the location’s program.
  • Consider testing before meeting some who is at high risk for severe illness with COVID-19.

Where to Get Tested

Please take a look at our main COVID page for this information.

Understanding Test Results (CDC, 2022)

covid testing
  • If you test positive, know what steps to take to care for yourself and prevent others from getting sick.
  • If you test negative, this does not completely rule out an infection.
    • If you have symptoms, continue to follow safety precautions and keep yourself and others safe.
    • If you do not have symptoms but were exposed, take steps to stay safe after exposure.
  • For more information check CDC’s resources here:


Centers for Disease Control and Prevention. (2022). Testing for COVID-19. Retrieved from

County of Los Angeles. (2021). COVID-19: Testing. Retrieved from

Orange county Health Care Agency. (2021). Covid-19 Testing. Retrieved from

Ventura County Recovers. (2021). COVID-19 Testing Information. Retrieved from