COVID-19 testing overview

San Francisco COVID-19 testing data, including citywide tests collected and test positivity rate.

Sections

Testing is critical to the City's response to COVID-19. Testing enables us to identify COVID-19 cases. Then, we can begin contact tracing to prevent the spread of the virus. Testing also helps us to support residents who test positive. 

Total tests

Testing data includes tests collected by all medical providers. This includes the City and private providers (like Kaiser, One Medical, or Sutter).   

The 7-day rolling average of tests is the average of the total tests collected each day and the prior 6 days. This average shows the trend in testing and smooths out daily fluctuations. 

Data notes and sources

View source data

San Francisco tests include any tests where either of the following are true: 

  • The patient listed a San Francisco home address 

  • The test was collected within San Francisco but had a missing home address 

Total tests includes all test results: positive, negative, and indeterminate test results.   

This data was de-duplicated by individual and date. If a person gets tested several times on different dates, all tests are included in this data.  

Tests are shown on the date the test was collected.   

Read about how this data is updated and validated.

Test positivity

The test positivity rate is the percentage of tests that are positive for COVID-19. This rate shows the spread of COVID-19 in San Francisco. It helps us know if enough testing is being completed.   

The 7-day rolling test positivity rate is the running average of the test positivity rate. This shows the trend in test positivity and smooths out daily fluctuations.

Data notes and sources

View source data

Test positivity rate = (positive tests) / (positive + negative tests) 

The test positivity rate does not include indeterminate results. We calculate the positivity rate by:  

  • Adding up all positive tests   

  • Dividing by the total number of positive and negative tests   

7-day rolling average test positivity = (total positives for a day and prior 6 days) / (total positive + negative tests for same period) 

We calculate the 7-day rolling positivity rate by:  

  • Summing all positive tests for a certain day and the prior 6 days   

  • Dividing by total positive and negative tests over the same 7-day period   

Positive test ≠ new case 

The total number of positive tests is not equal to the total number of new cases. The City verifies each positive test result. During this verification, some positive tests may not represent a new case. For example: 

  • If one person tested positive several times, that represents only one case 

  • During interviews, we could find that a test is for a person living outside of San Francisco 

Tests are shown on the date the test was collected.   

Read about how this data is updated and validated.