About Delphi Epidata (including COVIDcast)

Delphi Epidata is a database platform, repository, and API for epidemiological signals (also called “indicators”). It was launched in 2016 and significantly revamped during the pandemic. Delphi Epidata was purpose-designed for hosting signals for epidemic and pandemic detection, tracking and forecasting. It has built-in support for data versioning, calendar reporting effects, anomaly and trend detection, backfill projection, privacy-based censoring, and geographic, temporal and demographic breakdown and aggregation. The Delphi Epidata repository contains over 500 different current or historical signals, tracking flu, COVID-19, dengue, norovirus and other pathogens, and covering all rungs of the severity pyramid.

We procure data streams that reflect epidemic and pandemic activity from a wide variety of sources – including unique industry partnerships and scraping of publicly available data – and extract from them in real-time disease-related signals at the finest possible geographic, demographic and temporal granularity.

The COVID-19 related portion of Delphi Epidata is also known as COVIDcast, and constitute what we believe may be the largest public repository of real-time, geographically-detailed indicators of COVID-19 activity in the U.S.

We make all our signals freely available in real-time to the greatest extent allowable, using a public API which is updated with new data daily. We also provide:

Some of the underlying data from which our signals are extracted would not exist or be publicly available without Delphi’s efforts. These include a massive national daily survey called the COVID-19 Trends and Impact Survey (CTIS) that we have deployed in partnership with Facebook, which has been taken by over 25 million Americans during 2020-2022; and aggregated counts extracted from an enormous database of de-identified medical insurance claims, covering more than 35% of the U.S. population, made possible through health system partners including Change Healthcare.

Severity Pyramid