Estimating the burden of influenza-associated hospitalizations and deaths in Chile during 2012-2014.

Viviana Sotomayor,Natalia Vergara,Sergio Loayza,Felipe De La Fuente,Rakhee Palekar,Rodrigo A Fasce

doi:10.1111/irv.12502

Abstract

BackgroundInfluenza is a vaccine preventable disease that causes important morbidity and mortality worldwide. Estimating the burden of influenza disease is difficult. However, there are some methods based in surveillance data and laboratory testing that can be used for this purpose.ObjectivesEstimating the burden of serious illness from influenza by means of hospitalization and death records during the period between 2012 and 2014, and using information from Severe Acute Respiratory Illness (SARI) surveillance.MethodsTo estimate the Chilean rate of influenza‐associated hospitalizations and deaths, we applied the influenza positivity of respiratory samples tested in six SARI surveillance sentinel hospitals to the hospitalizations and deaths from the records with ICD‐10 codes from influenza and pneumonia.ResultsAnnually, 5320 people are hospitalized for influenza and 447 die for this cause. The annual influenza‐associated hospitalization rate for the period was 71.5/100 000 person‐year for <5 years old, 11.8/100 000 person‐year for people between 5 and 64 years old; and 156.0/100 000 person‐year for ≥65 years. The annual mortality rate for the period was 0.08/100 000 person‐year for <5 years; 0.3/100 000 person‐year for people between 5 and 64 years; and 22.8/100 000 person‐year for ≥65 years.ConclusionsThis is the first study of influenza burden in Chile. Every year an important quantity of hospitalizations and deaths result from influenza infection. In countries in temperate zones, it is important to know the burden of influenza in order to prepare the health care network and to assess preventive intervention currently in practice and the new ones to implementing.

Highlights

Influenza is a vaccine-preventable disease that occurs worldwide and causes important morbidity and mortality, especially in high-risk groups such as children, adults 65 years of age and older, pregnant women, and individuals with chronic diseases
As awareness of the risks associated with influenza infection and the importance of influenza monitoring has increased, the surveillance system for influenza and other respiratory viruses has been strengthened in Chile
The system is currently based on sentinel surveillance for influenza-like illness (ILI), severe acute respiratory infection (SARI), and monitoring of visits to emergency wards; a decentralized laboratory network plus the Instituto de Salud Pública of Chile (ISP), which is a National Influenza Center recognized by World Health Organization (WHO),[6] conduct virologic surveillance of influenza

Summary

Introduction

Influenza is a vaccine-preventable disease that occurs worldwide and causes important morbidity and mortality, especially in high-risk groups such as children, adults 65 years of age and older, pregnant women, and individuals with chronic diseases. The sentinel influenza-proxy syndromic surveillance for SARI has been progressively implemented in the country since 2011 with the aim of characterizing severe acute respiratory infections associated with influenza and of monitoring the severity of influenza virus subtypes.[7] the burden of influenza disease is difficult to estimate, because influenza virus produces a wide range of symptoms and syndromes not very specific and it is unlikely that laboratory confirmation of cases is carried out routinely.[8,9] the seasonal increase in influenza virus coincides with that of other respiratory viruses that can cause a similar clinical picture and often bacterial superinfection occurs. In countries in temperate zones, it is important to know the burden of influenza in order to prepare the health care network and to assess preventive intervention currently in practice and the new ones to implementing

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