1742. Hospital-Acquired Influenza Among Hospitalized Patients, 2011-2015
Session: Oral Abstract Session: Influenza - Impact on Healthcare and Healthcare Providers
Saturday, October 29, 2016: 9:15 AM
Room: 388-390

Hospital-acquired infections can be associated with significant morbidity. We describe the prevalence and epidemiology of hospital-acquired (HA) influenza.


Patients hospitalized with laboratory-confirmed influenza and enrolled in the Influenza Hospitalization Surveillance Network (FluSurv-NET) during 2011–2015 with testing and symptom onset dates were included. Influenza testing was performed at the discretion of clinicians. HA influenza was defined as a test date and respiratory symptom onset >3 days after admission. We estimated the prevalence of HA influenza and described demographic and clinical characteristics of HA influenza patients.


Among 41,974 patients with laboratory-confirmed influenza, 463 (1%) had HA influenza. The proportion of HA cases did not vary by season. Among the 463 HA cases, 46 (10%) were children (0-17 years) and 417 (90%) were adults. The median time between admission and test date was 7 days (IQR 5, 14). Thirty-one (7%) HA cases were transferred from another hospital and 66 (14%) were admitted from a nursing or long-term care facility. Four-hundred nineteen (91%) HA cases had at least one underlying medical condition. Among 459 HA cases with available data on underlying conditions, 206 (45%) had cardiovascular disease, 111 (24%) had a neurologic or neuromuscular disorder, 110 (24%) were immunocompromised, 111 (24%) had renal disease, 74 (16%) had asthma or chronic lung disease, and 81 (18%) were obese. Influenza antiviral treatment was received by 383 (83%) of HA cases. The median length of stay after influenza diagnosis was 6 days (IQR 3, 13). Of 463 HA cases, 126 (27%) were in the intensive care unit (ICU) before HA influenza diagnosis, 22 (5%) were admitted to the ICU on or after date of HA influenza diagnosis and 36 (8%) died.


HA influenza represented 1% of patients in our hospital surveillance over 4 influenza seasons. Since testing was clinician-driven, prevalence may have been under-detected if influenza was not suspected and tested. Influenza vaccination in healthcare workers and family members of high-risk persons, good hospital infection control [to prevent transmission from other patients], and limiting ill persons from visiting or working in hospitals should be encouraged.

Charisse Nitura Cummings, MPH1, Shikha Garg, MD, MPH1, Eileen Katherine Nenninger, MD2, Pam Daily Kirley, MPH3, Nisha Alden, MPH4, Kimberly Yousey-Hindes, MPH, CPH5, Evan J. Anderson, MD6, Maya Monroe, MPH7, Seth Eckel, MPH8, Ruth Lynfield, MD, FIDSA9, Marisa Bargsten, MPH10, Shelley M. Zansky, PhD11, Nancy M. Bennett, MD12, Lilith Tatham, DVM, MPH13, Ann Thomas, MD, MPH14, Mary Lou Lindegren, MD, MPH15, Gregg M. Reed, MPH16, Monica Schroeder, MPH17 and Alicia M. Fry, MD, MPH18, (1)Centers for Disease Control and Prevention, Atlanta, GA, (2)University of Virginia School of Medicine, Charlottesville, VA, (3)California Emerging Infections Program, Oakland, CA, (4)Colorado Department of Public Health and Environment, Denver, CO, (5)Emerging Infections Program, Yale, New Haven, CT, (6)Pediatrics and Medicine, Emory University School of Medicine, Atlanta, GA, (7)Maryland Department of Health and Mental Hygiene, Baltimore, MD, (8)Communicable Disease Division, Michigan Department of Health and Human Services, Lansing, MI, (9)Minnesota Department of Health, St. Paul, MN, (10)New Mexico Department of Health, Santa Fe, NM, (11)New York State Department of Health, Albany, NY, (12)University of Rochester Medical Center, Rochester, NY, (13)Ohio Department of Health, Columbus, OH, (14)Department of Human Services, Health Services, Portland, OR, (15)Vanderbilt University School of Medicine, Nashville, TN, (16)Bureau of Epidemiology, Utah Department of Health, Salt Lake City, UT, (17)Council of State and Territorial Epidemiologists, Atlanta, GA, (18)Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA


C. Nitura Cummings, None

S. Garg, None

E. K. Nenninger, None

P. Daily Kirley, None

N. Alden, None

K. Yousey-Hindes, None

E. J. Anderson, None

M. Monroe, None

S. Eckel, None

R. Lynfield, None

M. Bargsten, None

S. M. Zansky, None

N. M. Bennett, None

L. Tatham, None

A. Thomas, None

M. L. Lindegren, None

G. M. Reed, None

M. Schroeder, None

A. M. Fry, None

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