Uses the data source from the CDC FluView and provides flu reporting data as either a single data frame or a list of data frames (depending on whether either WHO NREVSS or ILINet (or both) is chosen.

  region = "hhs",
  sub_region = 1:10,
  data_source = "ilinet",
  years = as.numeric(format(Sys.Date(), "%Y"))



one of "hhs", "census", "national", "state"


depends on the region_type.
For "national", the sub_region should be NA.
For "hhs", should be a vector between 1:10.
For "census", should be a vector between 1:9.
For "state", should be a vector of state/territory names or "all".


either of "who" (for WHO NREVSS) or "ilinet" or "all" (for both)


a vector of years to retrieve data for (i.e. 2014 for CDC flu season 2014-2015). Default value is the current year and all years values should be > 1997


If only a single data_source is specified, then a single data.frame is returned, otherwise a named list with each data.frame is returned.


A lookup table between HHS regions and their member states/territories is provided in hhs_regions.


There is often a noticeable delay when making the API request to the CDC. This is not due to a large download size, but the time it takes for their servers to crunch the data. Wrap the function call in httr::with_verbose if you would like to see what's going on.