COVID-19 Cases by Population Characteristics Over Time

A. SUMMARY
This dataset shows San Francisco COVID-19 cases by population characteristics and by specimen collection date. Cases are included on the date the positive test was collected.

On September 12, 2021, a new case definition of COVID-19 was introduced that includes criteria for enumerating new infections after previous probable or confirmed infections (also known as reinfections). A reinfection is defined as a confirmed positive PCR lab test more than 90 days after a positive PCR or antigen test. The first reinfection case was identified on December 7, 2021.

Population characteristics are subgroups, or demographic cross-sections, like age, race, or gender. The City tracks how cases have been distributed among different subgroups. This information can reveal trends and disparities among groups.

Data is lagged by five days, meaning the most recent specimen collection date included is 5 days prior to today. Tests take time to process and report, so more recent data is less reliable.

B. HOW THE DATASET IS CREATED
Data on the population characteristics of COVID-19 cases and deaths are from:
* Case interviews
* Laboratories
* Medical providers

These multiple streams of data are merged, deduplicated, and undergo data verification processes. This data may not be immediately available for recently reported cases because of the time needed to process tests and validate cases. Daily case totals on previous days may increase or decrease. Learn more.

Data are continually updated to maximize completeness of information and reporting on San Francisco residents with COVID-19.

Data notes on each population characteristic type is listed below.

Race/ethnicity
* We include all race/ethnicity categories that are collected for COVID-19 cases.
* The population estimates for the "Other" or “Multi-racial” groups should be considered with caution. The Census definition is likely not exactly aligned with how the City collects this data. For that reason, we do not recommend calculating population rates for these groups.

Gender
* The City collects information on gender identity using these guidelines.

Transmission type
* Information on transmission of COVID-19 is based on case interviews with individuals who have a confirmed positive test. Individuals are asked if they have been in close contact with a known COVID-19 case. If they answer yes, transmission category is recorded as contact with a known case. If they report no contact with a known case, transmission category is recorded as community transmission. If the case is not interviewed or was not asked the question, they are counted as unknown.

C. UPDATE PROCESS
Updates automatically at 05:00 AM Pacific Time each day. Redundant runs are scheduled at 07:00 AM and 09:00 AM in case of pipeline failure.

Dataset will not update on the business day following any federal holiday.

D. HOW TO USE THIS DATASET
Population estimates are only available for age groups and race/ethnicity categories. San Francisco population estimates for race/ethnicity and age groups can be found in a view based on the San Francisco Population and Demographic Census dataset. These population estimates are from the 2016-2020 5-year American Community Survey (ACS).

This dataset includes many different types of characteristics. Filter the “Characteristic Type” column to explore a topic area. Then, the “Characteristic Group” column shows each group or category within that topic area and the number of cases on each date.

New cases are the count of cases within that characteristic group where the positive tests were collected on that specific specimen collection date. Cumulative cases are the running total of all San Francisco cases in that characteristic group up to the specimen collection date listed.

This data may not be immediately available for recently reported cases. Data updates as more information becomes available.

To explore data on the total number of cases, use the COVID-19 Cases Over Time dataset.

E. ARCHIVED DATA
Certain population characteristics that were once included in this dataset are no longer being reported publicly. An archived copy of these data can be found at this dataset here: ARCHIVED: COVID-19 Cases by Population Characteristics Over Time.

The archived dataset contains data on the following population characteristics that are no longer being reported publicly:

• Skilled Nursing Facility Occupancy
  
• Sexual orientation
  
• Comorbidities
  
• Homelessness
  
• Single Room Occupancy (SRO) tenancy

F. CHANGE LOG

• 5/16/2023 - data on cases by sexual orientation, comorbidities, homelessness, and single room occupancy have been removed. See section ARCHIVED DATA for more detail.
  
• 4/6/2023 - the State implemented system updates to improve the integrity of historical data.
  
• 2/21/2023 - system updates to improve reliability and accuracy of cases data were implemented.
  
• 1/31/2023 - updated “population_estimate” column to reflect the 2020 Census Bureau American Community Survey (ACS) San Francisco Population estimates.
  
• 1/5/2023 - data on SNF cases removed. See section ARCHIVED DATA for more detail.
  
• 3/23/2022 - ‘Native American’ changed to ‘American Indian or Alaska Native’ to align with the census.
  
• 1/22/2022 - system updates to improve timeliness and accuracy of cases and deaths data were implemented.
  
• 7/15/2022 - reinfections added to cases dataset. See section SUMMARY for more information on how reinfections are identified.