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This is the API documentation for accessing the FluView (fluview) endpoint of Delphi’s epidemiological data.

General topics not specific to any particular endpoint are discussed in the API overview. Such topics include: contributing, citing, and data licensing.

FluView Data

Influenza-like illness (ILI) from U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet).

* Data is usually released on Friday


The base URL is:

See this documentation for details on specifying epiweeks, dates, and lists.



Parameter Description Type
epiweeks epiweeks list of epiweeks
regions regions list of region labels


Parameter Description Type
issues issues list of epiweeks
lag # weeks between each epiweek and its issue integer
auth password for private imputed data string


  • If both issues and lag are specified, only issues is used. If neither is specified, the current issues are used.


Field Description Type
result result code: 1 = success, 2 = too many results, -2 = no results integer
epidata list of results array of objects
epidata[].release_date   string or null
epidata[].region   string
epidata[].issue   integer
epidata[].epiweek   integer
epidata[].lag   integer
epidata[].num_ili   integer
epidata[].num_patients   integer
epidata[].num_providers   integer
epidata[].num_age_0   integer or null
epidata[].num_age_1   integer or null
epidata[].num_age_2   integer or null
epidata[].num_age_3   integer or null
epidata[].num_age_4   integer or null
epidata[].num_age_5   integer or null
epidata[].wili weighted percent influenza-like illness float
epidata[].ili percent influenza-like illness float
message success or error message string


  • If authorized via auth, private data is not included.

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"

FluView in HHS Regions 4 and 6 for the 2014/2015 flu season,hhs6&epiweeks=201440-201520

Updates to FluView on 2014w53, reported from 2015w01 through 2015w10 (national)

Code Samples

Libraries are available for 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).

JavaScript (in a web browser)

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


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"))