Johns Hopkins Begins To Provide U.S. COVID-19 Testing Data


The Johns Hopkins Coronavirus Resource Center is now providing COVID-19 testing data for the United States from publicly reported sources, a service that replaces the COVID Tracking Project's year-long collection effort that ended March 7, 2021.

The Coronavirus Resource Center's files will include Covid Tracking Project data up to March 3, 2021 and JHU-collected data from that date forward. The data dictionary details all the variables' name equivalences to match CTP to JHU names.

Differences in how Johns Hopkins classifies tests compared to CTP will result in sudden shifts in test positivity for several states. The calculation changes implemented on March 3 will appear as spikes in positivity.

The CRC explains its positivity calculation methodology here. Now that Johns Hopkins is collecting testing data directly from state and county government sources the CRC will routinely review positivity calculations.

The CRC is providing an up-to-date, read only version of testing data in JSON format at this location: This API contains only testing data at this time.

The Coronavirus Resource is adding data collection to its existing, year-long effort of providing analysis and visualizations about testing from leading public health experts. The CRC is working in coordination with CTP employees to ensure a smooth transition for the entities that rely on the data.

The CRC has provided a continuously updated source of COVID-19 data and expert guidance since the pandemic began in January 2020. Experts aggregate and analyze the best data available on COVID-19 — including cases, deaths, tests, contact tracing, and vaccinations — to help the public, policymakers and healthcare professionals worldwide respond to the pandemic.