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Delphi Epidata API

This is the home of Delphi’s epidemiological data API.


If you are interested in contributing:

  • For development of the API itself, see the development guide.
  • To suggest changes, additions, or other ways to improve, open an issue describing your idea.


We hope that this API is useful to others outside of our group, especially for epidemiological and other scientific research. If you use this API and would like to cite it, we would gratefully recommend the following copy:

David C. Farrow, Logan C. Brooks, Aaron Rumack, Ryan J. Tibshirani, Roni Rosenfeld (2015). Delphi Epidata API.

Data licensing

The majority of the data surfaced through this API is more or less just a carefully curated mirror of data acquired from various external parties. Such data is subject to its original licensing, where applicable.

Any data which is produced novelly by Delphi and is intentionally and openly surfaced by Delphi through this API is hereby licensed CC-BY. Endpoints, as specified by the source parameter, which are known to wholly or partially serve data under this license include:

  • covidcast
  • covidcast_meta
  • delphi
  • dengue_nowcast
  • dengue_sensors
  • meta*
  • nowcast
  • sensors

Creative Commons License


The base URL is:

Specifying Epiweeks, Dates, and Lists

Epiweeks use the U.S. definition. That is, the first epiweek each year is the week, starting on a Sunday, containing January 4. See this page for more information.

Formatting for epiweeks is YYYYWW and for dates is YYYYMMDD.

list parameters consist of a comma-separated list of individual values or, for numeric parameters, a hyphenated range of values. Examples include:

  • param=201530 (A single epiweek)
  • param=201401,201501,201601 (Several epiweeks)
  • param=200501-200552 (A range of epiweeks)
  • param=201440,201501-201510 (Several epiweeks, including a range)
  • param=20070101-20071231 (A range of dates)

Universal Parameters

The only universally required parameter is source, which must be one of the supported source names listed below, e.g., fluview.

Source-Specific Parameters

The parameters available for each source are documented in each linked source-specific API page.

COVID-19 Data

Source Name Description Restricted?
covidcast COVIDCast Delphi’s COVID-19 surveillance streams. no
covidcast_meta COVIDCast Metadata Metadata for Delphi’s COVID-19 surveillance streams. no

Influenza Data

Source Name Description Restricted?
afhsb AFHSB yes
cdc CDC Page Hits yes
delphi Delphi’s Forecast no
ecdc_ili ECDC ILI ECDC ILI data from the ECDC website. no
flusurv FluSurv FluSurv-NET data (flu hospitaliation rates) from CDC. no
fluview FluView Influenza-like illness (ILI) from U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). no
fluview_meta FluView Metadata Summary data about fluview. no
fluview_clinical FluView Clinical no
gft Google Flu Trends Estimate of influenza activity based on volume of certain search queries. Google has discontinued Flu Trends, and this is now a static data source. no
ght Google Health Trends Estimate of influenza activity based on volume of certain search queries. yes
kcdc_ili KCDC ILI KCDC ILI data from KCDC website. no
meta API Metadata Metadata for fluview, twitter, wiki, and delphi. no
meta_afhsb AFHSB Metadata yes
nidss_flu NIDSS Flu Outpatient ILI from Taiwan’s National Infectious Disease Statistics System (NIDSS). no
nowcast ILI Nearby A nowcast of U.S. national, regional, and state-level (weighted) percent ILI, available seven days (regionally) or five days (state-level) before the first ILINet report for the corresponding week. no
quidel Quidel Data provided by Quidel Corp., which contains flu lab test results. yes
sensors Delphi’s Digital Surveillance Sensors no
twitter Twitter Stream Estimate of influenza activity based on analysis of language used in tweets from HealthTweets. yes
wiki Wikipedia Access Logs Number of page visits for selected English, Influenza-related wikipedia articles. no

Dengue Data

Source Name Description Restricted?
dengue_nowcast Delphi’s Dengue Nowcast
dengue_sensors Delphi’s Dengue Digital Surveillance Sensors
nidss_dengue NIDSS Dengue Counts of confirmed dengue cases from Taiwan’s NIDSS. no
paho_dengue PAHO Dengue

Norovirus Data

Source Name Description Restricted?
meta_norostat NoroSTAT Metadata
norostat NoroSTAT Suspected and confirmed norovirus outbreaks reported by state health departments to the CDC.


Example URLs

FluView on 2015w01 (national)

  "result": 1,
  "epidata": [
      "release_date": "2017-10-24",
      "region": "nat",
      "issue": 201740,
      "epiweek": 201501,
      "lag": 143,
      "num_ili": 31483,
      "num_patients": 771835,
      "num_providers": 1958,
      "num_age_0": 7160,
      "num_age_1": 9589,
      "num_age_2": null,
      "num_age_3": 8072,
      "num_age_4": 3614,
      "num_age_5": 3048,
      "wili": 4.21374,
      "ili": 4.07898
  "message": "success"

Wikipedia Access article “influenza” on 2020w01

  "result": 1,
  "epidata": [
      "article": "influenza",
      "count": 6516,
      "total": 663604044,
      "hour": -1,
      "epiweek": 202001,
      "value": 9.81910834
  "message": "success"

Code Samples

Libraries are available for CoffeeScript, JavaScript, Python, and R. The following samples show how to import the library and fetch national FluView data for epiweeks 201440 and 201501-201510 (11 weeks total).

CoffeeScript (in Node.js)

# Import
{Epidata} = require('./delphi_epidata')
# Fetch data
callback = (result, message, epidata) ->
  console.log(result, message, epidata?.length)
Epidata.fluview(callback, ['nat'], [201440, Epidata.range(201501, 201510)])

JavaScript (in a web browser)

<!-- Imports -->
<script src="jquery.js"></script>
<script src="delphi_epidata.js"></script>
<!-- Fetch data -->
  var callback = function(result, message, epidata) {
    console.log(result, message, epidata != null ? epidata.length : void 0);
  Epidata.fluview(callback, ['nat'], [201440, Epidata.range(201501, 201510)]);


Optionally install the package using pip(env):

pip install delphi-epidata

Otherwise, place from this repo next to your python script.

# Import
from delphi_epidata import Epidata
# Fetch data
res = Epidata.fluview(['nat'], [201440, Epidata.range(201501, 201510)])
print(res['result'], res['message'], len(res['epidata']))


# Import
# Fetch data
res <- Epidata$fluview(list('nat'), list(201440, Epidata$range(201501, 201510)))
cat(paste(res$result, res$message, length(res$epidata), "\n"))

Related work

  • Cook, Samantha, et al. “Assessing Google flu trends performance in the United States during the 2009 influenza virus A (H1N1) pandemic.” PloS one 6.8 (2011): e23610.
  • Broniatowski, David A., Michael J. Paul, and Mark Dredze. “National and local influenza surveillance through Twitter: an analysis of the 2012-2013 influenza epidemic.” (2013): e83672.
  • Dredze, Mark, et al. “HealthTweets. org: A Platform for Public Health Surveillance using Twitter.” AAAI Conference on Artificial Intelligence. 2014.
  • Generous, Nicholas, et al. “Global disease monitoring and forecasting with Wikipedia.” (2014): e1003892.
  • Hickmann, Kyle S., et al. “Forecasting the 2013–2014 Influenza Season Using Wikipedia.” (2015): e1004239.
  • McIver, David J., and John S. Brownstein. “Wikipedia usage estimates prevalence of influenza-like illness in the United States in near real-time.” PLoS Comput Biol 10.4 (2014): e1003581.

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