Profile Picture Seth Billiau

created Oct 6 2022

updated Dec 1 2022

Description

Beginning on October 20, 2022, CDC retrieves aggregate case and death data from jurisdictional and state partners weekly instead of daily. This public use dataset contains weekly community transmission levels data for all available counties and jurisdictions as displayed on COVID Data Tracker's County View since October 20, 2022. Each week, the dataset is appended to contain the most recent week's data and is updated on Thursdays, typically by 8pm ET. Historical corrections are not made to these data if new case or testing information become available. A separate file is made available here (Weekly COVID-19 County Level of Community Transmission Historical Changes) if historically updated data are desired.
Related data
CDC provides the public with two active versions of COVID-19 county-level community transmission level data: this dataset with the levels as originally posted (Weekly Originally Posted dataset), updated weekly with the most recent week’s data since October 20, 2022, and a historical dataset with the county-level transmission data from January 22, 2020 (Weekly Historical Changes dataset).

Methods for calculating county level of community transmission indicator
The County Level of Community Transmission indicator uses two metrics: (1) total new COVID-19 cases per 100,000 persons in the last 7 days and (2) percentage of positive SARS-CoV-2 diagnostic nucleic acid amplification tests (NAAT) in the last 7 days. For each of these metrics, CDC classifies transmission values as low, moderate, substantial, or high (below and here). If the values for each of these two metrics differ (e.g., one indicates moderate and the other low), then the higher of the two should be used for decision-making.

CDC core metrics of and thresholds for community transmission levels of SARS-CoV-2
Total New Case Rate Metric: "New cases per 100,000 persons in the past 7 days" is calculated by adding the number of new cases in the county (or other administrative level) in the last 7 days divided by the population in the county (or other administrative level) and multiplying by 100,000. "New cases per 100,000 persons in the past 7 days" is considered to have a transmission level of Low (0-9.99); Moderate (10.00-49.99); Substantial (50.00-99.99); and High (greater than or equal to 100.00).

Test Percent Positivity Metric: "Percentage of positive NAAT in the past 7 days" is calculated by dividing the number of positive tests in the county (or other administrative level) during the last 7 days by the total number of tests conducted over the last 7 days. "Percentage of positive NAAT in the past 7 days" is considered to have a transmission level of Low (less than 5.00); Moderate (5.00-7.99); Substantial (8.00-9.99); and High (greater than or equal to 10.00).

If the two metrics suggest different transmission levels, the higher level is selected.

The reported transmission categories include:

Low Transmission Threshold: Counties with fewer than 10 total cases per 100,000 population in the past 7 days, and a NAAT percent test positivity in the past 7 days below 5%;

Moderate Transmission Threshold: Counties with 10-49 total cases per 100,000 population in the past 7 days or a NAAT test percent positivity in the past 7 days of 5.0-7.99%;

Substantial Transmission Threshold: Counties with 50-99 total cases per 100,000 population in the past 7 days or a NAAT test percent positivity in the past 7 days of 8.0-9.99%;

High Transmission Threshold: Counties with 100 or more total cases per 100,000 population in the past 7 days or a NAAT test percent positivity in the past 7 days of 10.0% or greater.

Blank: total new cases in the past 7 days are not reported (county data known to be unavailable) and the percentage of positive NAATs tests during the past 7 days (blank) are not reported.

Data Suppression
To prevent the release of data that could be used to identify people, data cells are suppressed for low frequency. When the case counts used to calculate the total new case rate metric ("cases_per_100K_7_day_count_change") is greater than zero and less than 10, this metric is set to "suppressed" to protect individual privacy. If the case count is 0, the total new case rate metric is still displayed.
The data in this dataset are considered provisional by CDC and are subject to change until the data are reconciled and verified with the state and territorial data providers.
Archived data
CDC has archived two prior versions of these datasets. Both versions contain the same 7 data elements reflecting community transmission levels for all available counties and jurisdictions; however, the datasets were updated daily. The archived datasets can be found here:

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Category
Public Health Surveillance
Permissions
Public
Tags
covid-19, coronavirus, community transmission, county, case, laboratory
Row Label
Most Recent County Community Transmission Level posted on COVID Data Tracker
SODA2 Only
Yes
Common Core
Contact Name
Surveillance Review and Response Group
Contact Email
eocevent394@cdc.gov
Publisher
CDC
Public Access Level
public
References
https://data.cdc.gov/Public-Health-Surveillance/Weekly-COVID-19-County-Level-of-Community-Transmis/jgk8-6dpn
Bureau Code
009:20
Program Code
009:020
Geographic Coverage
US
Temporal Applicability
2022-10-20/-
Update Frequency
Weekly
Data Quality
Suggested Citation
Centers for Disease Control and Prevention, COVID-19 Response. Weekly COVID-19 County Level of Community Transmission as Originally Posted (version date: [Month] [Date], [Year]).
Geospatial Resolution
State, County
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