title: Pneumonia among adults hospitalized with laboratory-confirmed seasonal influenza virus infection-United States, 2005-2008.
abstract: BACKGROUND
  Influenza and pneumonia combined are the leading causes of death due to infectious diseases in the United States. We describe factors associated with pneumonia among adults hospitalized with influenza.
  
  
  METHODS
  Through the Emerging Infections Program, we identified adults ≥ 18 years, who were hospitalized with laboratory-confirmed influenza during October 2005 through April 2008, and had a chest radiograph (CXR) performed. Pneumonia was defined as the presence of a CXR infiltrate and either an ICD-9-CM code or discharge summary diagnosis of pneumonia.
  
  
  RESULTS
  Among 4,765 adults hospitalized with influenza, 1392 (29 %) had pneumonia. In multivariable analysis, factors associated with pneumonia included: age ≥ 75 years, adjusted odds ratio (AOR) 1.27 (95 % confidence interval 1.10-1.46), white race AOR 1.24 (1.03-1.49), nursing home residence AOR 1.37 (1.14-1.66), chronic lung disease AOR 1.37 (1.18-1.59), immunosuppression AOR 1.45 (1.19-1.78), and asthma AOR 0.76 (0.62-0.92). Patients with pneumonia were significantly more likely to require intensive care unit (ICU) admission (27 % vs. 10 %), mechanical ventilation (18 % vs. 5 %), and to die (9 % vs. 2 %).
  
  
  CONCLUSIONS
  Pneumonia was present in nearly one-third of adults hospitalized with influenza and was associated with ICU admission and death. Among patients hospitalized with influenza, older patients and those with certain underlying conditions are more likely to have pneumonia. Pneumonia is common among adults hospitalized with influenza and should be evaluated and treated promptly.
authors: Epidemiology and Prevention Branch, Influenza Division, CDC, 1600 Clifton Road, Atlanta, GA, USA. izj7@cdc.gov.|Epidemic Intelligence Service, CDC, 1600 Clifton Road, Atlanta, GA, 30329, USA. izj7@cdc.gov.
authors: Shikha
authors: S
authors: Garg
authors: Epidemiology and Prevention Branch, Influenza Division, CDC, 1600 Clifton Road, Atlanta, GA, USA. bwc8@cdc.gov.
authors: Seema
authors: S
authors: Jain
authors: Epidemiology and Prevention Branch, Influenza Division, CDC, 1600 Clifton Road, Atlanta, GA, USA. hgj0@cdc.gov.
authors: Fatimah S
authors: FS
authors: Dawood
authors: Epidemiology and Prevention Branch, Influenza Division, CDC, 1600 Clifton Road, Atlanta, GA, USA. dvk3@cdc.gov.
authors: Michael
authors: M
authors: Jhung
authors: Epidemiology and Prevention Branch, Influenza Division, CDC, 1600 Clifton Road, Atlanta, GA, USA. hvv9@cdc.gov.
authors: Alejandro
authors: A
authors: Pérez
authors: Epidemiology and Prevention Branch, Influenza Division, CDC, 1600 Clifton Road, Atlanta, GA, USA. iqi0@cdc.gov.|Atlanta Research and Education Foundation, 4 Executive Park East NE, Suite 355, Atlanta, GA 30329, USA. iqi0@cdc.gov.
authors: Tiffany
authors: T
authors: D'Mello
authors: California Emerging Infections Program, 360 22nd Street, Suite 750, Oakland, California, 94612, USA. reingold@berkeley.edu.
authors: Arthur
authors: A
authors: Reingold
authors: Colorado Department of Public Health and Environment, 4300 Cherry Creek S Dr, Denver, Colorado, 80246, USA. Ken.Gershman@state.co.us.
authors: Ken
authors: K
authors: Gershman
authors: Connecticut Emerging Infections Program, Yale University, 1 Church Street, New Haven, Connecticut, 06510, USA. james.meek@yale.edu.
authors: James
authors: J
authors: Meek
authors: Georgia Division of Public Health and Georgia Emerging Infections Program, 2 Peachtree Street NW, Atlanta, Georgia, 30303, USA. kea3@cdc.gov.
authors: Kathryn E
authors: KE
authors: Arnold
authors: Emory University School of Medicine and Atlanta VAMC, 1648 Pierce Dr NE, Atlanta, Georgia, 30322, USA. mfarley@emory.edu.
authors: Monica M
authors: MM
authors: Farley
authors: Maryland Department of Health and Mental Hygiene, 201 West Preston Street, 3rd Floor, Baltimore, MD, 21201, USA. ryanp@dhmh.state.md.us.
authors: Patricia
authors: P
authors: Ryan
authors: Minnesota Department of Health, P.O. Box 64975, St. Paul, Minnesota, 55164, USA. ruth.lynfield@state.mn.us.
authors: Ruth
authors: R
authors: Lynfield
authors: Minnesota Department of Health, P.O. Box 64975, St. Paul, Minnesota, 55164, USA. Craig.Morin@vdh.virginia.gov.
authors: Craig
authors: C
authors: Morin
authors: New Mexico Department of Health, 1190 St. Francis Drive, N1353, P.O. Box 26110, Santa Fe, NM, 87502-6110, USA. Joan.Baumbach@state.nm.us.
authors: Joan
authors: J
authors: Baumbach
authors: New Mexico Department of Health, 1190 St. Francis Drive, N1353, P.O. Box 26110, Santa Fe, NM, 87502-6110, USA. EHancock@salud.unm.edu.
authors: Emily B
authors: EB
authors: Hancock
authors: Emerging Infections Program, New York State Department of Health, ESP, Corning Tower, Rm 651, Albany, New York, 12237, USA. smz04@health.state.ny.us.
authors: Shelley
authors: S
authors: Zansky
authors: Department of Medicine, University of Rochester School of Medicine and Dentistry, New York, 14620, USA. Nancy_Bennett@URMC.Rochester.edu.|Monroe County, Department of Public Health, 451 E Henrietta Rd #2, Rochester, New York, 14620, USA. Nancy_Bennett@URMC.Rochester.edu.
authors: Nancy
authors: N
authors: Bennett
authors: Oregon Public Health Division, 800 NE Oregon St., Suite 772, Portland, OR, 97232, USA. ann.thomas@state.or.us.
authors: Ann
authors: A
authors: Thomas
authors: Vanderbilt University School of Medicine, Village at Vanderbilt - Suite 2600, 1500 21st Avenue South, Nashville, TN, 37212, USA. William.schaffner@vanderbilt.edu.
authors: William
authors: W
authors: Schaffner
authors: Epidemiology and Prevention Branch, Influenza Division, CDC, 1600 Clifton Road, Atlanta, GA, USA. lyf8@cdc.gov.
authors: Lyn
authors: L
authors: Finelli
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications / Q000453:epidemiology* / Q000821:virology; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011024:Pneumonia, Viral / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000821:virology; D011446:Prospective Studies; D011859:Radiography; D012121:Respiration, Artificial; D012307:Risk Factors; D012621:Seasons; D014481:United States / Q000453:epidemiology; D055815:Young Adult