
Methods: A national severe influenza surveillance network includes reporting to HCDCP of 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. We evaluated risk factors for death using univariate & multivariate analyses
Results: 248 cases were recorded (median age 67 yrs, 54.7% male, 87.1% high risk pts with comorbidities). Influenza A was noted in 56.5%. 111 deaths were recorded (median age 57 yrs, 55% male). In 64 (57.7%) deaths, influenza A was diagnosed [A(H1N1): 36%, A(H3N2): 64%]. 99/111 (89.2%) deaths occurred in pts with immunization indications; 15 were immunized. ARDS (OR 3.43 (95%CI 1.27 - 9.3) p=0.006), renal insufficiency (OR 3.9; 95% CI 1.4-11.3, p = 0.01), occurrence of secondary bacterial infection & septic shock (OR 4.4; 95% CI 1.2-16.4, p=0.015) were risk factors for death. Influenza A cases did not differ from B regarding age, comorbidities, rates of intubation or death. Within 31 vaccinated cases influenza A was more prevalent to B (77.4% vs. 22.6%, p=0.06)
Conclusion: ARDS, renal insufficiency & the presence of secondary infections or septic shock were risk factors for death in a mixed A & B season. Influenza B did not differ from A in the risk for complications & death. Vaccine failures were noted especially among serious influenza A cases, consistent with the reported drift of A(H3N2)

A. Andreopoulou,
None
G. Spala, None
O. Kalkouni, None
T. Lytras, None
A. Baka, None
S. Koukouli, None
E. Velioti, None
T. Georgakopoulou, None
C. Hadjichristodoulou, None
S. Tsiodras, None