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COVID-19 Status Update for 04/16/2021

Marin County COVID-19 Status Update for April 16 includes a reduction in COVID-19 cases among LatinX residents; Monitoring local “Breakthrough” cases; An opportunity to get your COVID-19 vaccine; and updated local COVID-19 data… Read More

Updated Guidelines for Quarantine




Effective: December 5, 2020




This advisory modifies and shortens the duration of quarantine for those exposed to SARS-CoV-2.




SARS-CoV-2, the virus that causes COVID-19, is predominantly spread from person-to-person. Limiting contact between infected people and others can prevent transmission. Quarantining those who have close contact with infected persons separates potential secondary cases from others, preventing onward spread.


Until now, the standard quarantine interval for COVID-19 has been 14 days. On December 2, 2020, Centers for Disease Control and Prevention (CDC) updated guidance to provide local health jurisdictions an option to reduce the length of quarantine to reduce the burden imposed by quarantine and to increase community compliance. CDC scientists modeled the residual post-quarantine transmission risk, expressed as a percent of total transmission, per day of quarantine if quarantine were discontinued that day. The addition of diagnostic testing for asymptomatic persons reduces the estimated post-quarantine transmission risk.



  • Marin County residents can continue to be quarantined for 14 days without testing per existing recommendations (estimated post-quarantine transmission risk 0 – 3%). 
  • All exposed persons must monitor for symptoms thru Day 14; if any symptoms develop, they should immediately self-isolate and contact their healthcare provider for COVID-19 testing
  • Marin County residents can reduce quarantine to 10 days without testing if no symptoms have developed (estimated post-quarantine transmission risk 0-11%).
  • Marin County residents can reduce quarantine to 7 days if a diagnostic molecular test for COVID-19 (RT-PCR) is negative and if no symptoms have developed (estimated post-quarantine transmission risk 2 – 9%). 
    • The specimen must be collected no earlier than 5 days after last contact with a person who has COVID-19. 
    • Quarantine cannot be discontinued earlier than after Day 7.  Exposed persons must have negative COVID-19 test result in order to end quarantine in less than 10 days. 


Related guidance documents for patients: