In!uenza and In!uenza-Like Illnesses in Poland in the Epidemic Season 2010/2011 According to the SENTINEL In!uenza Surveillance System

$e aim of this study was to analyze data collected by the SENTINEL in!uenza surveillance system in Poland in the first post-pandemic season 2010/2011. $e results include weeks 35/2010–17/2011. Physicians registered weekly number of in!uenza-like illnesses and collected specimens. Laboratory tests were done using PCR and/or real-time PCR or immuno!uorescence. Laboratories also isolated the in!uenza virus. In!uenza-like illness incidence amounted to 2802.7/100000. Weekly incidence ranged from 11.3/100000 to 232/100000. $e most a#ected group was children 0–4 years. In!uenza-like illness peak occurred between weeks 02/2011 and 11/2011. In!uenza infections were confirmed in 34.9% of specimens. More cases were caused by in!uenza A, including A(H1N1)pdm09 than in!uenza B (59.9% vs. 40.1%). $e isolated strains were similar to A/California/7/2009 or B/Brisbane/60/2008. Season 2010/2011 in Poland did not di#er from the rest of Europe. Further improvement is necessary, especially in the area of specimen collection at the beginning of an epidemic season and carrying out the isolation of the in!uenza virus. K e y w o r d s: A(H1N1)pdm09, diagnostics, in!uenza, respiratory viruses, sentinel, surveillance Romanowska M. et al. 1 52 significance of in!uenza surveillance was clearly proved in 2009. In that time, a novel in!uenza virus A(H1N1) of swine origin emerged and in the end of April 2009 quickly spread to Europe when a typical in!uenza epidemic season had just ended (ECDC, 2010a; ECDC, 2010b; Neumann and Kawaoka, 2011). $e aim of this study was to analyse virological and epidemiological data derived from the SENTINEL in!uenza surveillance system in Poland in the first epidemic season a'er the 2009 H1N1 in!uenza pandemic.