sfgov/covid19-cases-by-geography-and-date-d2ef-idww

  • cases
  • census tract
  • covid
  • covid-19
  • mapping
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COVID-19 Cases by Geography and Date

COVID-19 Cases by Geography and Date

<i><b>Note: As of April 16, 2021, this dataset will update daily with a five-day data lag.</i></b>

<strong>A. SUMMARY</strong>

This dataset contains COVID-19 positive confirmed cases aggregated by several different geographic areas and by day. COVID-19 cases are mapped to the residence of the individual and shown on the date the positive test was collected. In addition, 2019 American Community Survey (ACS) 5-year population estimates are included to calculate the cumulative rate per 10,000 residents.

Dataset covers cases going back to March 2nd, 2020 when testing began. This data may not be immediately available for recently reported cases and data will change to reflect as information becomes available. Data updated daily.

Geographic areas summarized are:

  1. <a href="https://data.sfgov.org/Geographic-Locations-and-Boundaries/Analysis-Neighborhoods/p5b7-5n3h">Analysis Neighborhoods</a>

  2. <a href="https://data.sfgov.org/Geographic-Locations-and-Boundaries/Census-2010-Tracts-for-San-Francisco/rarb-5ahf">Census Tracts</a>

  3. <a href="https://www.census.gov/programs-surveys/geography/guidance/geo-areas/zctas.html">Census Zip Code Tabulation Areas</a>

<strong>B. HOW THE DATASET IS CREATED</strong>

Addresses from the COVID-19 case data are geocoded by the San Francisco Department of Public Health (SFDPH). Those addresses are spatially joined to the geographic areas. Counts are generated based on the number of address points that match each geographic area for a given date.

The 2019 ACS estimates for population provided by the Census are used to create a cumulative rate which is equal to (cumulative count up to that date / acs_population) * 10000) representing the number of total cases per 10,000 residents (as of the specified date).

COVID-19 case data undergo quality assurance and other data verification processes and are continually updated to maximize completeness and accuracy of information. This means data may change for previous days as information is updated.

<strong>C. UPDATE PROCESS</strong>

Geographic analysis is scripted by SFDPH staff and synced to this dataset daily at 05:00 Pacific Time.

<strong>D. HOW TO USE THIS DATASET</strong>

This dataset can be used to track the spread of COVID-19 throughout the city, in a variety of geographic areas. Note that the new cases column in the data represents the number of new cases confirmed in a certain area on the specified day, while the cumulative cases column is the cumulative total of cases in a certain area as of the specified date.

<em>Privacy rules in effect</em>

To protect privacy, certain rules are in effect:

  1. Any area with a cumulative case count less than 10 are dropped for all days the cumulative count was less than 10. These will be null values.

  2. Once an area has a cumulative case count of 10 or greater, that area will have a new row of case data every day following.

  3. Cases are dropped altogether for areas where acs_population < 1000

  4. Deaths data are not included in this dataset for privacy reasons. The low COVID-19 death rate in San Francisco, along with other publicly available information on deaths, means that deaths data by geography and day is too granular and potentially risky. Read more in our <a href="https://data.sfgov.org/COVID-19/COVID-19-Data-Tracker-Publishing-Privacy-Guideline/9aj4-um47">privacy guidelines</a>

<em>Rate suppression in effect where counts lower than 20</em>

Rates are not calculated unless the cumulative case count is greater than or equal to 20. Rates are generally unstable at small numbers, so we avoid calculating them directly. We advise you to apply the same approach as this is best practice in epidemiology.

<em>A note on Census ZIP Code Tabulation Areas (ZCTAs)</em>

ZIP Code Tabulation Areas are special boundaries created by the U.S. Census based on ZIP Codes developed by the USPS. They are not, however, the same thing. ZCTAs are areal representations of routes. Read how the Census develops ZCTAs on their website.

Columns

NameSocrata field nameColumn name in sgr mountData typeDescription
multipolygonmultipolygonmultipolygonMultiPolygonThe geometry in multipolygon format stored in EPSG:4326 coordinate system
New Confirmed Casesnew_confirmed_casesnew_confirmed_casesNumberThe count of new cases in the area for the specified date
idididTextThe identifier for the area type
area_typearea_typearea_typeTextType of geographic area, one of: Citywide, Census Tract, Analysis Neighborhood, or ZCTA (ZIP Code Tabulation Area)
acs_populationacs_populationacs_populationNumberThe population from the latest 5-year estimates from the American Community Survey (2015-2019)
Cumulative Confirmed Casescumulative_confirmed_casescumulative_confirmed_casesNumberThe cumulative total cases in the area as of the specified date
last_updated_atlast_updated_atlast_updated_atCalendar date
data_loaded_atdata_loaded_atdata_loaded_atCalendar date
Rate of Cumulative Confirmed Caserate_of_cumulative_confirmed_caserate_of_cumulative_confirmed_caseNumberThe rate of cumulative cases in the area, calculated as (cumulative cases/acs_population) * 10000 which is a rate per 10,000 residents
Specimen Collection Datespecimen_collection_datespecimen_collection_dateCalendar dateDate the positive test was collected for the confirmed cases

Upstream Metadata