title: 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: BACKGROUND
  The 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.
  
  
  METHODS
  Data 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.
  
  
  RESULTS
  Nine 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.
  
  
  CONCLUSIONS
  Countries 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.
authors.affiliation: Department of Primary and Community Care, Radboud University Medical Centre, Nijmegen, the Netherlands. Tamara.meerhoff@radboudumc.nl.
authors.forename: Tamara J
authors.initials: TJ
authors.lastname: Meerhoff
authors.affiliation: Institute of Public Health, Tirana, Albania. artan.simaku@gmail.com.
authors.forename: Artan
authors.initials: A
authors.lastname: Simaku
authors.affiliation: Institute of Public Health, Tirana, Albania. ulqinakud@gmail.com.
authors.forename: Dritan
authors.initials: D
authors.lastname: Ulqinaku
authors.affiliation: State Hygiene and Anti-epidemic Inspectorate, Yerevan, Armenia. liana_torosyan@mail.ru.
authors.forename: Liana
authors.initials: L
authors.lastname: Torosyan
authors.affiliation: The Republican Research and Practical Center for Epidemiology and Microbiology (RRPCEM), Minsk, Belarus. gribkova@belriem.by.
authors.forename: Natalia
authors.initials: N
authors.lastname: Gribkova
authors.affiliation: The Republican Center for Hygiene, Epidemiology and Public Health, Minsk, Belarus. veranikash@yahoo.com.
authors.forename: Veronica
authors.initials: V
authors.lastname: Shimanovich
authors.affiliation: National Centre for Disease Control and Public Health (NCDC), Tbilisi, Georgia. gio.ncdc@gmail.com.
authors.forename: Giorgi
authors.initials: G
authors.lastname: Chakhunashvili
authors.affiliation: National Centre for Disease Control and Public Health (NCDC), Tbilisi, Georgia. i.karseladze.ncdc@gmail.com.
authors.forename: Irakli
authors.initials: I
authors.lastname: Karseladze
authors.affiliation: Committee of Sanitary and Epidemiological Surveillance MOH, Astana, Kazakhstan. a.yesmagambetova@mz.gov.kz.
authors.forename: Aizhan
authors.initials: A
authors.lastname: Yesmagambetova
authors.affiliation: Scientifical-Practical Center of Sanitary and Epidemiological Expertise and Monitoring, Almaty, Kazakhstan. kainagul@yahoo.com.
authors.forename: Ainagul
authors.initials: A
authors.lastname: Kuatbayeva
authors.affiliation: National Virological Laboratory, Department of the State Sanitary and Epidemiological Surveillance, Ministry of Health of Kyrgyz Republic, Bishkek, Kyrgyzstan. Zuridin@mail.ru.
authors.forename: Zuridin
authors.initials: Z
authors.lastname: Nurmatov
authors.affiliation: Department of State Sanitary Epidemiological Surveillance, Bishkek, Kyrgyzstan. d_otorbaeva@mail.ru.
authors.forename: Dinagul
authors.initials: D
authors.lastname: Otorbaeva
authors.affiliation: Cantacuzino Institute, National Reference Centre for Influenza, Bucharest, Romania. elupulescu@cantacuzino.ro.
authors.forename: Emilia
authors.initials: E
authors.lastname: Lupulescu
authors.affiliation: National Institute of Public Health, National Centre for Communicable Diseases Surveillance and Control, Bucharest, Romania. odette.popovici@insp.gov.ro.
authors.forename: Odette
authors.initials: O
authors.lastname: Popovici
authors.affiliation: National Influenza Centre at the Research Institute of Influenza, St Petersburg, Russian Federation. smorodintseva@influenza.spb.ru.
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Smorodintseva
authors.affiliation: National Influenza Centre at the Research Institute of Influenza, St Petersburg, Russian Federation. anna.sominin@gmail.com.
authors.forename: Anna
authors.initials: A
authors.lastname: Sominina
authors.affiliation: L.V. Gromashevskyi Institute of Epidemiology and Infectious Diseases, Kiev, Ukraine. olg_golubka@ukr.net.
authors.forename: Olga
authors.initials: O
authors.lastname: Holubka
authors.affiliation: L.V. Gromashevskyi Institute of Epidemiology and Infectious Diseases, Kiev, Ukraine. otsvetkova@ukr.net.
authors.forename: Olga
authors.initials: O
authors.lastname: Onyshchenko
authors.affiliation: WHO Regional Office for Europe, Copenhagen, Denmark. cbr@euro.who.int.
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Brown
authors.affiliation: WHO Regional Office for Europe, Copenhagen, Denmark. dgo@euro.who.int.
authors.forename: Diane
authors.initials: D
authors.lastname: Gross
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005060:Europe / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000401:mortality* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012141:Respiratory Tract Infections / Q000401:mortality* / Q000473:pathology; D012307:Risk Factors; D018571:Sentinel Surveillance; D012720:Severity of Illness Index; D055815:Young Adult