title: The burden and etiology of community-onset pneumonia in the aging Japanese population: a multicenter prospective study.
abstract: BACKGROUND
  The increasing burden of pneumonia in adults is an emerging health issue in the era of global population aging. This study was conducted to elucidate the burden of community-onset pneumonia (COP) and its etiologic fractions in Japan, the world's most aged society.
  
  
  METHODS
  A multicenter prospective surveillance for COP was conducted from September 2011 to January 2013 in Japan. All pneumonia patients aged ≥ 15 years, including those with community-acquired pneumonia (CAP) and health care-associated pneumonia (HCAP), were enrolled at four community hospitals on four major islands. The COP burden was estimated based on the surveillance data and national statistics.
  
  
  RESULTS
  A total of 1,772 COP episodes out of 932,080 hospital visits were enrolled during the surveillance. The estimated overall incidence rates of adult COP, hospitalization, and in-hospital death were 16.9 (95% confidence interval, 13.6 to 20.9), 5.3 (4.5 to 6.2), and 0.7 (0.6 to 0.8) per 1,000 person-years (PY), respectively. The incidence rates sharply increased with age; the incidence in people aged ≥ 85 years was 10-fold higher than that in people aged 15-64 years. The estimated annual number of adult COP cases in the entire Japanese population was 1,880,000, and 69.4% were aged ≥ 65 years. Aspiration-associated pneumonia (630,000) was the leading etiologic category, followed by Streptococcus pneumoniae-associated pneumonia (530,000), Haemophilus influenzae-associated pneumonia (420,000), and respiratory virus-associated pneumonia (420,000), including influenza-associated pneumonia (30,000).
  
  
  CONCLUSIONS
  A substantial portion of the COP burden occurs among elderly members of the Japanese adult population. In addition to the introduction of effective vaccines for S. pneumoniae and influenza, multidimensional approaches are needed to reduce the pneumonia burden in an aging society.
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Konosuke
authors.initials: K
authors.lastname: Morimoto
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Motoi
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ishifuji
authors.affiliation: Department of General Internal Medicine, Kameda Medical Center, Chiba, Japan.
authors.forename: Makito
authors.initials: M
authors.lastname: Yaegashi
authors.affiliation: Department of Internal Medicine, Juzenkai Hospital, Nagasaki, Japan.
authors.forename: Norichika
authors.initials: N
authors.lastname: Asoh
authors.affiliation: Department of Internal Medicine, Chikamori Hospital, Kochi, Japan.
authors.forename: Naohisa
authors.initials: N
authors.lastname: Hamashige
authors.affiliation: Department of General Internal Medicine, Ebetsu City Hospital, Hokkaido, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Abe
authors.affiliation: Department of Pulmonology, Kameda Medical Center, Chiba, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Aoshima
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Koya
authors.initials: K
authors.lastname: Ariyoshi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D044466:Asian People; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000209:etiology* / Q000382:microbiology; D005260:Female; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012111:Residence Characteristics; D055815:Young Adult
references.citation: N Engl J Med. 2001 Mar 1;344(9):665-71
references.pmid: 11228282
references.citation: Am Rev Respir Dis. 1963 Oct;88:473-83
references.pmid: 14068432
references.citation: Clin Infect Dis. 2004 Dec 1;39(11):1642-50
references.pmid: 15578365
references.citation: Am J Respir Crit Care Med. 2005 Feb 15;171(4):388-416
references.pmid: 15699079
references.citation: Clin Infect Dis. 2006 Feb 15;42(4):518-24
references.pmid: 16421796
references.citation: J Am Geriatr Soc. 2006 Feb;54(2):296-302
references.pmid: 16460382
references.citation: J Infect. 2006 Sep;53(3):166-74
references.pmid: 16375972
references.citation: Clin Infect Dis. 2007 Mar 1;44 Suppl 2:S27-72
references.pmid: 17278083
references.citation: Thorax. 2007 Mar;62(3):253-9
references.pmid: 16928720
references.citation: Thorax. 2008 Jan;63(1):42-8
references.pmid: 17573440
references.citation: J Am Geriatr Soc. 2008 Mar;56(3):577-9
references.pmid: 18315680
references.citation: MMWR Morb Mortal Wkly Rep. 2013 Nov 22;62(46):909-13
references.pmid: 24257198
references.citation: Clin Infect Dis. 2014 Mar;58(6):854-64
references.pmid: 24344141
references.citation: J Infect Chemother. 2014 Jul;20(7):450-3
references.pmid: 24767466
references.citation: Jpn J Infect Dis. 2014;67(4):269-75
references.pmid: 25056072
references.citation: Antimicrob Agents Chemother. 2014 Sep;58(9):5262-8
references.pmid: 24957843
references.citation: Hum Vaccin Immunother. 2014;10(5):1334-6
references.pmid: 24763136
references.citation: Emerg Infect Dis. 2008 May;14(5):727-33
references.pmid: 18439353
references.citation: Neth J Med. 2008 Oct;66(9):378-83
references.pmid: 18990781
references.citation: Respir Med. 2009 Feb;103(2):309-16
references.pmid: 18804355
references.citation: J Am Geriatr Soc. 2009 Mar;57(3):482-5
references.pmid: 19187415
references.citation: Thorax. 2009 Oct;64 Suppl 3:iii1-55
references.pmid: 19783532
references.citation: Epidemiol Infect. 2010 Jan;138(1):61-8
references.pmid: 19538821
references.citation: Thorax. 2009 Dec;64(12):1062-9
references.pmid: 19454409
references.citation: Clin Infect Dis. 2010 Jan 15;50(2):202-9
references.pmid: 20014950
references.citation: Pediatr Infect Dis J. 2010 Jan;29(1):75-7
references.pmid: 19907358
references.citation: Cochrane Database Syst Rev. 2010;(2):CD004876
references.pmid: 20166072
references.citation: J Infect. 2010 Nov;61(5):364-71
references.pmid: 20692290
references.citation: Clin Infect Dis. 2011 May;52 Suppl 4:S296-304
references.pmid: 21460288
references.citation: Pediatr Infect Dis J. 2011 Jan;30(1):11-8
references.pmid: 20686433
references.citation: Vaccine. 2011 Jul 26;29(33):5386-92
references.pmid: 21651943
references.citation: Gerontologist. 2011 Aug;51(4):425-32
references.pmid: 21804114
references.citation: Public Health Rep. 2011 Sep-Oct;126 Suppl 3:81-8
references.pmid: 21836741
references.citation: Lancet. 2011 Sep 17;378(9796):1106-15
references.pmid: 21885107
references.citation: Thorax. 2012 Jan;67(1):71-9
references.pmid: 20729232
references.citation: J Infect Dis. 2012 May 15;205(10):1589-92
references.pmid: 22448012
references.citation: Am J Respir Crit Care Med. 2012 Aug 15;186(4):325-32
references.pmid: 22700859
references.citation: Lancet. 2012 Dec 15;380(9859):2095-128
references.pmid: 23245604
references.citation: Intern Med. 2013;52(3):317-24
references.pmid: 23370738
references.citation: Gerodontology. 2013 Mar;30(1):3-9
references.pmid: 22390255
references.citation: Cochrane Database Syst Rev. 2013;1:CD000422
references.pmid: 23440780
references.citation: PLoS One. 2013;8(4):e60273
references.pmid: 23565216
references.citation: PLoS One. 2013;8(9):e75131
references.pmid: 24040394
references.citation: Am J Respir Crit Care Med. 2013 Oct 15;188(8):985-95
references.pmid: 23855620