COVID-19 Testing

The St. Charles County Department of Public Health conducts free testing for SARS-CoV-2, the virus that causes COVID-19. Tests are administered by appointment. Please call the COVID-19 Hotline at 636-949-1899 with questions.

You must enter your full legal name when 
registering for testing.

PLEASE NOTE: You will immediately receive an email from upon successful registration and scheduling with this system. Scheduling confirmation and test results are sent by email. Please make certain your email information is correct before submitting and check your email (including the spam folder) after you register. If you do not have an email address, call the COVID-19 Hotline at 636-949-1899 between 8 a.m. and 5 p.m., Monday-Friday. 
Tests are performed in the parking lot of the Department of Public Health building (1650 Boone's Lick Road, St. Charles 63301). Please enter the parking lot directly from Boone's Lick Road and proceed to a parking space marked "Parking for COVID Testing Only." These dedicated spaces are in front of the last door on the lower level of the building on your left. Stay in your car and call 636-949-7400, ext. 6249 to let staff know you have arrived. 
Please do not eat, drink (even water), smoke, chew gum or brush teeth within 15 minutes of arrival for testing.

Additional Testing Locations

Learn more about COVID-19 vaccinations by calling the COVID-19 Hotline at 636-949-1899 or register for a vaccine appointment online

drive-through COVID swab testingTesting is performed by polymerase chain reaction (PCR) using a nasopharyngeal swab or by rapid nucleic acid amplification (NAAT) using a mid-turbinate nasal swab to determine if there is an active infection. Please note that this test requires a swab being put in your nose, which may cause mild, temporary discomfort. This is not an antibody test, which denotes past infection.

Testing Recommendations

  • If you are a close contact** and you are experiencing symptoms, the optimal time to be tested is 0-4 days after the onset of your first symptom.
  • If you are a close contact** but are not experiencing any symptoms, the optimal time to be tested is 5-9 days after you were exposed to the infected person. Performing a test too soon after exposure can result in a false negative test result.
  • Individuals in select industries or who have a high incidence of public contact are at higher risk for exposure to COVID-19. Testing can help to monitor the health of these individuals. These industries include individuals who work or reside in:
    • Health care or a long-term care facility.
    • A congregate living facility.
    • Correctional facilities, such as jails or prisons.
    • Government.
    • First responders, including paramedics, emergency medical technicians, law enforcement officers and firefighters.
    • Critical infrastructure, including grocery stores, pharmacies, public utilities, childcare, sanitation or other public-facing jobs.
  • If you are not a close contact** and are not experiencing symptoms, the Department of Public Health does not recommend that you get tested unless testing is required to participate in sports, enter your place of employment, travel to a foreign country, or enter school. If you need to be tested for one of these activities, please note that PCR test results may take up to 5 days to be reported. Rapid amplification (NAAT) tests are reported within 24 hours.
  • The Department of Public Health does not recommend testing more than once a month unless you become a close contact or develop symptoms of COVID-19 infection. If these circumstances arise, follow the recommendations above.

While Awaiting Test Results

The Department of Public Health requests that you self-isolate* while waiting for your test results if you are a close contact** of someone who tested positive for SARS-CoV-2 within the past 2 weeks or if you are experiencing any of the following symptoms:

  • Cough
  • Shortness of breath
  • Difficulty breathing

Or, if you are experiencing at least two of the following symptoms:

  • Fever
  • Chills
  • Muscle pain
  • Headache
  • Sore throat
  • New loss of taste or smell
  • Stuffy or runny nose
  • Diarrhea

Receiving Test Results

A positive test result indicates the detection of the SARS CoV-2 virus in your test specimen. This is the virus that causes COVID-19.

Rapid Amplification Test Results

  • If your test is positive, you will receive this result within 24 hours of the test by email notification.
  • If your test is negative, the Department of Public Health typically does not report this result, but will send a second sample to an outside laboratory for standard RT-PCR analysis.

RT-PCR Test Results

  • An RT-PCR test is more accurate than rapid amplification testing. It is possible for your RT-PCR test to be positive, even when the rapid amplification test is negative. RT-PCR results are provided to you by email from the laboratory in 3-5 days following the date your sample was collected.

What's Next

  • If you receive a positive test result, notify the people you have been in contact** with and begin to self-isolate.* Your close contacts should speak with a medical provider about their additional needs.
  • If you have questions or concerns about the testing or your result, please call the St. Charles County COVID-19 Hotline at 636-949-1899.

*Self-isolate means that you should stay indoors and completely avoid contact with other people, including others within your household, as much as possible.
**A close contact is defined as anyone who was within 6 feet of an infected person for at least 15 minutes, starting 48 hours before the person began to feel sick until the time the person was isolated.