Surveillance for severe acute respiratory infections (SARI) in hospitals in the WHO European region - an exploratory analysis of risk factors for a severe outcome in influenza-positive SARI cases

Abstract

BackgroundThe 2009 H1N1 pandemic highlighted the need to routinely monitor severe influenza, which lead to the establishment of sentinel hospital-based surveillance of severe acute respiratory infections (SARI) in several countries in Europe. The objective of this study is to describe characteristics of SARI patients and to explore risk factors for a severe outcome in influenza-positive SARI patients.MethodsData on hospitalised patients meeting a syndromic SARI case definition between 2009 and 2012 from nine countries in Eastern Europe (Albania, Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Romania, Russian Federation and Ukraine) were included in this study. An exploratory analysis was performed to assess the association between risk factors and a severe (ICU, fatal) outcome in influenza-positive SARI patients using a multivariate logistic regression analysis.ResultsNine countries reported a total of 13,275 SARI patients. The majority of SARI patients reported in these countries were young children. A total of 12,673 SARI cases (95%) were tested for influenza virus and 3377 (27%) were laboratory confirmed. The majority of tested SARI cases were from Georgia, the Russian Federation and Ukraine and the least were from Kyrgyzstan. The proportion positive varied by country, season and age group, with a tendency to a higher proportion positive in the 15+ yrs age group in six of the countries. ICU admission and fatal outcome were most often recorded for influenza-positive SARI cases aged >15 yrs. An exploratory analysis using pooled data from influenza-positive SARI cases in three countries showed that age > 15 yrs, having lung, heart, kidney or liver disease, and being pregnant were independently associated with a fatal outcome.ConclusionsCountries in Eastern Europe have been able to collect data through routine monitoring of severe influenza and results on risk factors for a severe outcome in influenza-positive SARI cases have identified several risk groups. This is especially relevant in the light of an overall low vaccination uptake and antiviral use in Eastern Europe, since information on risk factors will help in targeting and prioritising vulnerable populations.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0722-x) contains supplementary material, which is available to authorized users.

Estimating burden of influenza‐associated influenza‐like illness and severe acute respiratory infection at public healthcare facilities in Romania during the 2011/12‐2015/16 influenza seasons

“…This is similar to what was reported by18 from a study of SARI in the WHO European Region from 2009/2010 to 2011/2012 where 6 countries (Albania, Armenia, Georgia, Kazakhstan, Romania, and Ukraine) report CFP for laboratory‐confirmed SARI cases 18 . The CFP varied from 0%‐70%, but in over half of the seasons, the CFP was <2%.…”

Rapid risk assessment during the early weeks of the 2015‐2016 influenza season in Ukraine

“…The most commonly reported underlying conditions in those cases that died were cardiovascular disease and obesity, both previously described as independent risk factors associated with fatal outcomes for laboratory‐positive SARI in eastern Europe 18, 19. However, accurate estimates of deaths due to influenza are difficult to obtain 20.…”

Evaluation of Patients Diagnosed With Severe Acute Respiratory Tract Infection: 2015-2016 Influenza Season

“…Çalışmamızda da benzer olarak baş-vuru öncesi ortalama şikayet süresi 3.8 gündü. Vakalarımız arasında influenza aşılaması (%4.1) Avrupa ülkelerine benzer biçimde oldukça düşük oranda belirlendi (%0-4.1) (17).…”

“…Avrupa ülkelerinde yetişkin SARI vakalarının değerlen-dirildiği bir çalışmada, 2011-2012 sezonunda Hırvatistan ve Romanya'da influenza örneklerinde pozitiflik oranı sırasıyla %40 ve %35.2 olarak bildirilmiştir (17). Buna benzer olarak ülkemizde 20. hafta sonu itibarıyla GBH ve SARI vakaları için gönderilen numunelerde toplam pozitiflik oranı %45.3 olarak rapor edilmiştir (22) İnfluenzayla ilişkili mortalite sıklığına dair bildirimler değişkenlik göstermektedir.…”

“…ABD'de 2015-2016 sezonunda 23. hafta sonu itibarıyla influenza pnömonisiyle ilişkili mortalite oranı %5.7 olarak rapor edilmiştir (1). Avrupa ülkelerinde yaş ve sezonla ilişkili olarak farklılık göstermekle birlikte mortalitenin %0.8-18.8 arasında değiştiği bildirilmektedir (17). Snacken ve arkadaşları (19)'nın çalışmasında yatarak takip edilen hastalar için mortalitenin %15.6 olduğu rapor edilmiş-tir.…”