Skip to main content

Table 1 Number of samples tested and percentages attributable to influenza A and B virus types in Italy, as reported to the virological surveillance system, by season (from 2004/2005 to 2016/2017)

From: Co-circulation of the two influenza B lineages during 13 consecutive influenza surveillance seasons in Italy, 2004–2017

SeasonSamples testedInfluenza virus detections (%)N. of Influenza A viruses (%)N. of Influenza B viruses (%)Estimated ILI cases
2004/20053226971 (30)718 (74)253 (26)6336.000
2005/20062719307 (11)228 (74)79 (26)2347.000
2006/20071869643 (34)607 (94)36 (6)3675.000
2007/20081870548 (29)286 (52)262 (48)4692.000
2008/20092213733 (33)688 (94)45 (6)4105.000
2009/201016,4336282 (38)6230 (> 99)52 (< 1)5507.000
2010/201191932874 (31)2082 (72)792 (28)5917.000
2011/201246771672 (36)1610 (96)62 (4)5000.000
2012/201355352114 (38)894 (42)1220 (58)6181.000
2013/201444261033 (23)999 (97)34 (3)4542.000
2014/201510,2993734 (36)3133 (84)601 (16)6299.000
2015/201689852457 (27)1044 (42)1413 (58)4877.000
2016/201712,0343518 (29)3339 (95)179 (5)5440.000
All seasons83,47926,886 (32.2)21,858 (81.3)*5028 (18.7)*64,918.000
  1. Influenza-like illness (ILI). Source: Influenza Sentinel Surveillance network (InfluNet);
  2. *76.7 and 23.3%, when adjusted for differences in total ILI incidence by season
\