Laboratory-confirmed deaths caused by influenza A (H1N1)pdm09 in the Santa Catarina State, Brazil, 2009-2014

Abstract

Introduction: Little information is available on the evolution of influenza A (H1N1)pdm09-related mortality in Brazil. Methods: During the period 2009-2014, official epidemiological surveillance and mortality data were used to ascertain influenza-related deaths in the Santa Catarina State in Brazil. Results: The highest overall mortality rate (2.3 per 100,000) was observed in 2009. Pregnant women constituted the highest risk group (mortality rate 18.0 per 100,000). Following vaccination of high-risk groups, the rate reduced sharply but peaked again in 2012. It subsequently decreased, albeit more gradually. Conclusions: Influenza A (H1N1)pdm09 mortality demonstrated a cyclic pattern, with two peaks followed by a gradual decrease.