ANALYSIS OF FATAL OUTCOME DUE TO INFLUENZA AND RISK FACTORS ASSOCIATED, ROMANIA, OCTOBER 2009 – MAY 2011

摘要

Limited data are available from Central and Eastern Europe on risk factors for severe complications of influenza. Such data are essential to prioritize prevention and treatment resources and to identify specific priority populations for seasonal influenza vaccination. Objectives: To use sentinel surveillance data to identify risk factors for fatal outcomes among hospitalized patients with severe acute respiratory infections (SARI), and among hospitalized patients with laboratory confirmed influenza. Methods: Retrospective analysis of case-based surveillance data collected from 26 sentinel hospitals in Romania during the 2009/2010 and 2010/2011 winter influenza seasons was performed to evaluate risk factors for fatal outcomes using multivariate logistic regression. Results: During the 2009/2010 and 2010/2011 winter influenza seasons sentinel hospitals reported 661 SARI patients of which 230 (35%) tested positive for influenza. In the multivariate analyses, infection with influenza A(H1N1)pdm09 was the strongest risk factor for death among hospitalized SARI patients (OR:6.6; 95% CI:3.3-13.1). Among patients positive for influenza A(H1N1)pdm09 virus infection (n=148), being pregnant (OR:7.1; 95% CI:1.6-31.2), clinically obese (OR:2.9;95% CI:1.6-31.2) and having an immuno-compromising condition (OR:3.7;95% CI:1.1-13.4) were significantly associated with fatal outcomes. Only 1.7% of SARI patients reported receiving either the 2009 monovalent pandemic vaccine, or the 2010/2011 trivalent seasonal influenza vaccine during the two years of surveillance. Conclusion: Our findings indicate that a substantial number of annual hospitalizations and deaths in Romania may be preventable with influenza vaccination. Hospital-based sentinel surveillance for SARI may provide a mechanism for monitoring the relative severity of influenza seasons, to identify priority populations for influenza vaccination using local data during each influenza season, and during pandemics as well.