COVID-19 Close Contacts

Calculating Your Quarantine End Date

To determine the end date for your quarantine period if someone you have come into contact with has tested positive for COVID-19, use this date calculator. You should also follow the guidelines listed below during your quarantine period.

Close Contacts

In accordance with the recent Judgment issued by the Circuit Court of Cole County, Missouri in Shannon Robinson, et al. v. Missouri Department of Health and Senior Services, 20AC-CC00515 (Nov. 22, 2021), the St. Charles County Department of Public Health (SCCDPH) shall not be issuing orders of quarantine to close contacts who have been exposed to individuals who have tested positive for COVID-19.

  • If you have tested positive for COVID-19, you should let your family, friends, and other close contacts know about your positive status so they can monitor their own health. No one from SCCDPH will be communicating with your contacts. If you or your contacts have questions or concerns, please contact the COVID-19 Information Hotline at 636-949-1899.

Contacts With Recent Vaccination of Full Series or Booster Dose

Contacts who fall into the following categories do not need to observe a period of quarantine but should wear a well-fitting mask around others for at least 10 days after exposure. For all those exposed, best practice would also include a test for SARS-CoV-2 at Day 5 after exposure.

  • Two doses of either mRNA vaccine series (Pfizer or Moderna) PLUS a booster dose
  • One dose of Johnson & Johnson followed by 1 dose of mRNA OR 1 additional dose of Johnson & Johnson
  • One dose of Johnson & Johnson less than 2 months ago
  • Two doses of either mRNA series less than 6 months ago  

Contacts Who Have Not Had Recent Vaccination 

Contacts who fall into the following categories should quarantine at home for a minimum of five days. Contacts who remain asymptomatic for five days can discontinue at-home quarantine but should wear a well-fitting mask around others for five additional days. For all those exposed, best practice would also include a test for SARS-CoV-2 at Day 5 after exposure.

  • Two doses of either mRNA series more than 6 months ago and have not received a booster dose
  • One dose of Johnson & Johnson vaccine more than 2 months ago and no booster dose
  • One dose of mRNA vaccine
  • Unvaccinated 

If symptoms occur after an exposure to COVID-19, immediately isolate until a negative test confirms symptoms are not attributable to COVID-19.