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Testing & Contact Tracing

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COVID-19 TESTING AND CONTACT TRACING

See Isolation & Quarantine Guidance below.

TESTING

Safe, easy, no-cost testing is widely available at County-sponsored locations, private testing companies, pharmacies, and through at-home test kits available for purchase at pharmacies and other retailers.

There are two types of COVID-19 test: Polymerase chain reaction (PCR) tests, which typically return results within 72 hours, although times vary depending upon demand and rapid antigen tests, often referred to as at-home test kits, which return results in a few minutes.

Results from PCR tests are reported by laboratories to San Mateo County Health, which provides the information to the California Department of Public Health. Results from rapid-antigen tests are not reported to public health officials, and San Mateo County Health is not collecting the results.

The County of San Mateo offers only PCR testing at 10 sites, which it operates through contracted providers Curative and LHI/OptumServe.

WHEN TO GET TESTED

According to guidance from the California Department of Public Health:

  • You should immediately get tested for COVID-19 if you are feeling any symptoms – regardless of your vaccination status. COVID-19 symptoms can feel like a common cold (including just “the sniffles”), seasonal allergies, or flu. Symptoms include fever or chills, cough, shortness of breath and difficulty breathing.
  • If you’ve been exposed to COVID-19 and are not fully vaccinated, get tested right away. If you test negative, retest 5-7 days after your exposure date. Those who are unvaccinated should also test 1-3 days before and 3-5 days after any high-risk events.
  • If you were fully vaccinated when exposed, you should get tested 5-7 days after close contact with someone who has recently tested positive.

The CDPH testing fact sheet is here, and CDPH guidance related to travel is here.

CONTACT TRACING

If you test positive on a PCR test, you may receive a text message from the number 23393. San Mateo County Health uses the state of California’s text-message-based virtual assistant to provide information, connect you to resources, and collect more information from you. It is safe to click on the link and start communicating with San Mateo County Health through the Virtual Assistant.

Learn more about the Virtual Assistant here.

Your responses, which are confidential, will help determine if anyone near you, including your family and friends, is at risk of exposure to COVID-19. We will not ask for your social security number, immigration status, or financial information. Depending on their vaccination, your close contacts may be offered testing and may be asked to quarantine themselves to help prevent the spread of the disease, even if they are not showing symptoms.

ISOLATION & QUARANTINE

San Mateo County Health is following guidelines from the California Department of Public Health.

Flyers from the CDPH: 

Persons Who Test Positive for COVID-19 (Isolation) Recommended Action

Everyone, regardless of vaccination status, previous infection or lack of symptoms.

  • Stay home for at least 5 days. 
  • Isolation can end after day 5 if symptoms are not present or are resolving and a test performed on day 5 or later is negative.
  • If unable to test or choosing not to test, and symptoms are not present or are resolving, isolation can end after day 10.
  • If fever is present, isolation should be continued until fever resolves. 
  • If symptoms, other than fever, are not resolving continue to isolate until symptoms are resolving or until after day 10.
  • Wear a well-fitting mask around others for a total of 10 days, especially in indoor settings
Persons Who are Exposed to Someone with COVID-19 (Quarantine) Recommended Action
  • Unvaccinated; OR 
  • Vaccinated and booster-eligible but have not yet received their booster dose. 
  • Stay home for at least 5 days, after your last contact with a person who has COVID-19. 
  • Test on day 5. 
  • Quarantine can end after day 5 if symptoms are not present and a test on day 5 or later is negative.
  • If unable to test or choosing not to test, and symptoms are not present, quarantine can end after day 10.
  • Wear a well-fitting mask around others for a total of 10 days, especially in indoor settings
  • Strongly encouraged to get vaccinated or boosted.
  • If testing positive, follow isolation recommendations above. 
  • If symptoms develop, test and stay home.
Persons Who are Exposed to Someone with COVID-19 (No Quarantine)  Recommended Action
  • Boosted; OR 
  • Vaccinated, but not yet booster-eligible.
  • Test on day 5. 
  • Wear a well-fitting mask around others for 10 days, especially in indoor settings
  • If testing positive, follow isolation recommendations above.
  • If symptoms develop, test and stay home.