Laboratory influenza surveillance in Νorthern Greece, 2014-2015

Following the influenza pandemic in 2009, the influenza virus continues to threaten public health with its yearly epidemics. This is a review of the laboratory influenza surveillance in northern Greece, during 2014-2015. Starting from the 40th week of 2013 until the 20th week of 2014, 519 clinical samples were examined. The three influenza A(H1N1)pdm09, A(H3N2) and B types were detected at 39.1% of the cases. Further molecular analysis of the haemagglutinin and neuraminidase genes from representative samples followed in order to assess the effectiveness of the vaccine and of the most frequently used antiviral drugs. Α(Η1Ν1)pdm09 strains were antigenically related to the vaccine virus strains, B strains were antigenically related to another strain, which was selected for the 2015-2016 vaccine, while A(H3N2) viruses exhibited important antigenic drift, that reduced the vaccine effectiveness. No resistant strains to oseltamivir were detected. As the World Health Organization suggests, constant influenza surveillance is essential at a national and international level.