Open AccessInfluenza surveillance in E urope: comparing intensity levels calculated using the moving epidemic method
Author(s) -
Vega Tomás,
Lozano José E.,
Meerhoff Tamara,
Snacken René,
Beauté Julien,
Jorgensen Pernille,
Ortiz de Lejarazu Raúl,
Domegan Lisa,
Mossong Joël,
Nielsen Jens,
Born Rita,
Larrauri Amparo,
Brown Caroline
Publication year - 2015
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/irv.12330
Subject(s) - incidence (geometry) , demography , intensity (physics) , geography , medicine , mathematics , physics , geometry , quantum mechanics , sociology
Objectives Although influenza‐like illnesses ( ILI ) and acute respiratory illnesses ( ARI ) surveillance are well established in Europe, the comparability of intensity among countries and seasons remains an unresolved challenge. The objective is to compare the intensity of ILI and ARI in some European countries. Design and setting Weekly ILI and ARI incidence rates and proportion of primary care consultations were modeled in 28 countries for the 1996/1997–2013/2014 seasons using the moving epidemic method ( MEM ). We calculated the epidemic threshold and three intensity thresholds, which delimit five intensity levels: baseline, low, medium, high, and very high. The intensity of 2013/2014 season is described and compared by country. Results The lowest ILI epidemic thresholds appeared in S weden and E stonia (below 10 cases per 100 000) and the highest in B elgium, D enmark, H ungary, P oland, S erbia, and S lovakia (above 100 per 100 000). The 2009/2010 season was the most intense, with 35% of the countries showing high or very high intensity levels. The E uropean epidemic period in season 2013/2014 started in J anuary 2014 in S pain, P oland, and G reece. The intensity was between low and medium and only G reece reached the high intensity level, in weeks 7 to 9/2014. Some countries remained at the baseline level throughout the entire surveillance period. Conclusions Epidemic and intensity thresholds varied by country. Influenza‐like illnesses and ARI levels normalized by MEM in 2013/2014 showed that the intensity of the season in E urope was between low and medium in most of the countries. Comparing intensity among seasons or countries is essential for understanding patterns in seasonal epidemics. An automated standardized model for comparison should be implemented at national and international levels.