LAUSR

ObjectiveThe Plan of Information on Acute Respiratory Infections in Catalonia (PIDIRAC) included the surveillance of severe hospitalized cases of laboratory-confirmed influenza (SHCLCI) in 2009. The objective of this study was to determine the clinical, epidemiological and virological features of SHCLCI recorded in 12 sentinel hospitals during five influenza seasons.ResultsFrom a sample of SHCLCI recorded during the 5 influenza epidemics seasons from 2010–2011 to 2014–2015, Cases were confirmed by PCR and/or viral isolation in cell cultures from respiratory samples. A total of 1400 SHCLCI were recorded, 33% required ICU admission and 12% died. The median age of cases was 61 years (range 0–101 years); 70.5% were unvaccinated; 80.4% received antiviral treatment (in 79.6 and 24% of cases within 48 h after hospital admission and the onset of symptoms, respectively); influenza virus A [37.9% A (H1N1)pdm09, 29.3% A (H3N2)] was identified in 87.7% of cases. Surveillance of SHCLCI provides an estimate of the severity of seasonal influenza epidemics and the identification and characterization of at-risk groups in order to facilitate preventive measures such as vaccination and early antiviral treatment.