Get the relative intensity of influenza A circulation

get_country_intensity data() returns data on the annual intensity of influenza circulation in each calendar year. Following doi:10.1126/science.aag1322 Gostic et al. Science, (2016), we define 1 as the average intensity. Seasons with intensities greater than 1 have more flu A circulation than average, and seasons with intensities less than 1 are mild.

Usage

get_country_intensity_data(country, max_year, min_specimens = 50)

Arguments

country

country of interest. Run show_available_countries() for valid inputs.

max_year

last year of interest. Results will be generated from 1918:max_year.

min_specimens

if fewer than min_specimens (default 50) were tested in the country and year of interest, the function will substitute data from the corresponding WHO region.

Value

A tibble showing the year and intensity score.

Details

For 1918-1996, we use annual intensities from Gostic et al., Science, (2016). For 1997-present, we calculate country or region-specific intensities using surveillance data from WHO Flu Mart. Intensity is calculated as: [fraction of processed samples positive for flu A]/[mean fraction of processed samples positive for flu A]. Country-specific data are used by default. Regional or global data are substituted when country-specific data contain too few observations or fail quality checks. Global data are only used in years when regional data are insufficient.