495. Influenza, Obesity and Timely Administration of Oseltamivir: A Prospective Study of Patient Outcomes
Session: Poster Abstract Session: Respiratory Infections: Influenza
Thursday, October 8, 2015
Room: Poster Hall
Background: Individuals with obesity were found to have increased disease severity and mortality during the 2009 Influenza A/H1N1 pandemic. The objective of this study was to identify outcomes of influenza illness and risk factors for severe complications, specifically lower pulmonary disease (LPD), among patients with obesity.   

Methods: We prospectively identified hospitalized patients with laboratory-confirmed influenza. Body mass index (BMI), demographics, medical history, and disease outcome were collected through chart abstraction and patient interviews. Obese patients were compared to non-obese patients for rates of LPD (defined as infiltrates or consolidation noted on chest x-ray and/or hypoxia) and intensive care unit admission, controlling for chronic comorbidities and medical history.  

Results: 55 patients were enrolled during the 2011-2013 and 2012-2013 influenza seasons. Of these, 26 (47%) had Class I through III Obesity, defined as a BMI of 30.0 or greater. Overall, oseltamivir was initiated in patients with obesity more quickly following the onset of symptoms (median 2 (IQR: 1.5-5) versus 3 (IQR: 2-6) days; mean 3.3 (SD: 2.4) versus 5.2 (SD: 4.9)) p=0.04). After controlling for timely receipt of antivirals (defined as within 2 days of symptoms onset), obesity was associated with intensive care unit admission (OR: 6.02 ((95% C.I. 1.1, 34.5) p=0.04)) and LPD was increased but this did not reach statistical significance (OR: 3.4 (95% C.I. 0.9, 12.7) p=0.02). Patients with obesity had shorter lengths of stay controlling for timely receipt of antivirals (2.1 (95% C.I. 0.2 to 3.6) days shorter; p=0.03). Among all subjects, late administration of antivirals was associated with ICU admission (OR: 7.5 (95% C.I. 1.02, 54.4) p=0.047) and lower pulmonary disease (OR: 5.8 (95% C.I. 1.4, 24.3) p=0.02) after controlling for poorer health status, obesity, use of steroids, and history of diabetes.

Conclusion: We found an increase in influenza disease severity in individuals with obesity hospitalized during the 2011/2012 and 2012/2013 influenza season. Notably, we found that late treatment with oseltamivir, outside of the CDC-recommended 48 hour window, was associated with increased rates of pneumonia and ICU admission compared to timely treatment.

Emily T. Martin, MPH, PhD1, Richard Evans, BS2, Carolyn Archer, M.P.H.3, Joshua G. Petrie, MPH1, Samia Arshad, Epidemiologist/MPH4 and Keith Kaye, MD, MPH, FIDSA, FSHEA5, (1)Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, (2)University of Michigan School of Public Health, Ann Arbor, MI, (3)Wayne State University, Detroit, MI, (4)Infectious Diseases, Henry Ford Health System, Detroit, MI, (5)Medicine, Wayne State University, Detroit, MI


E. T. Martin, Pfizer: Grant Investigator , Grant recipient

R. Evans, None

C. Archer, None

J. G. Petrie, None

S. Arshad, None

K. Kaye, Detroit Medical Center and Wayne State University: Consultant and Grant Investigator , Consulting fee and Grant recipient

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