We examined risk factors for influenza related death in severe cases in Greece during the 2016-17 influenza season. We also analyzed influenza vaccination data in this severely affected patient cohort.
A national severe influenza surveillance system supported by the Hellenic CDC monitors all laboratory-confirmed influenza cases admitted to ICU &/or in-hospital deaths of influenza patients. Each case is followed up daily, with a structured questionnaire until discharged from the hospital. We evaluated risk factors for death using univariate & multivariate analyses.
A total of 288 cases were recorded until week 18/2016 (median age 72 yrs, 63.2% male, 89.9% high risk pts with comorbidities for whom flu immunization was indicated). 24.7% of severe influenza cases were reported as obese (BMI>30 kg/m2). Influenza A was noted in 86.5% with AH3N2 typed in 99.9 % of cases. AH3N2 influenza was noted in older individuals compared to B influenza (mean age 68 yrs vs 55.5 yrs respectively, p<0.01). 108/279 (37.5%) deaths were recorded (median age 74.5 yrs, 45.7% male, 9 pts still hospitalized in week 18th2017). In multivariate analyses, risk factors for death were: presence of ARDS [OR: 2.1; 95%CI 1-4.6, p=0.05], presence of multi-organ dysfunction (MODS) [OR: 25.4; 95%CI 7.9-81.4, p<0.001, adjusting for concomitant ARDS], and the presence of an immunocompromising condition [OR: 2; 95% CI 1-4.2, p=0.05]. Intubated patients, with severe influenza, awaiting ICU bed placement, had significantly poorer outcomes (OR for death 2.6; 95%CI 2.1-3.2, p<0.001). 63/231 (27.2%) of cases with available data reported vaccination with the seasonal vaccine. Vaccination did not protect against MODS (OR: .99; 95%CI .7-1.5, p=1) or death (OR: 1.04; 95%CI .8-1.2, p=0.9). Among influenza A affected pts, 58/203 (28.6%) were vaccinated compared to 5/28 (17.9%) pts with B influenza (chi-square 1.4, p=0.2).
ARDS, MODS and the presence of an immune compromising condition were risk factors for death in a AH3N2 predominant season in Greece. Vaccination failures were most frequently noted in type A influenza affected patients. Vaccination did not protect against MODS or death in this severe influenza cohort. Surge capacity issues and hospitalization outside the ICU was associated with a higher risk for death.
A. Andreopoulou, None
E. Mouratidou, None
O. Kalkouni, None
T. Georgakopoulou, None
S. Tsiodras, None