A Manual for Estimating Disease Burden Associated With Seasonal Influenza

Overview

This manual is targeted at epidemiologists and data analysts with basic epidemiological training who are responsible for data analysis and interpretation at influenza sentinel surveillance sites and the National Surveillance Office (NSO) or Ministry of Health (MOH). After completing the appropriate sections of the manual the end-user should be able to i) estimate the morbidity burden due to influenza-associated respiratory infections (expressed as incidence rates where data on the denominator population at risk are available) and the proportional contribution of influenza to respiratory infections, ii) estimate the proportion of influenza-associated cases of severe respiratory infections who died (case fatality ratio), iii) assess the plausibility of the results, iv) identify gaps in influenza surveillance (particularly related to data collection) and improve sentinel surveillance for influenza.

The Supplement:

The guide “Using a hospital admission survey to determine rates of influenza-associated severe acute respiratory”, developed by the Influenza Division of the United States Centers for Disease Control and Prevention, in collaboration with WHO’s Global Influenza Programme, serves as a supplement to the WHO publication “A manual for estimating disease burden associated with seasonal influenza”. This guide provides public health officials with the tools to prepare and perform a hospital admission survey (HAS) to determine what proportion of the population living in a hospital’s catchment area seeks care at the sentinel site for a severe respiratory illness, compared with other admitting facilities in the area. The catchment population will serve as the denominator when calculating rates of influenza-associated hospitalizations for the hospital. Developed as an extension of the WHO manual, this HAS guide cites, where appropriate, relevant section numbers from the WHO manual.