title: Microorganisms Causing Community-Acquired Acute Bronchitis: The Role of Bacterial Infection.
abstract: BACKGROUND
  Although acute bronchitis is quite common, there is relatively limited information regarding the microorganisms that are involved in this illness.
  
  
  METHODS
  We performed a prospective study of acute bronchitis at 31 hospitals and clinics in Korea from July 2011 to June 2012. Sputum specimens were collected for polymerase chain reaction (PCR) and culture of microorganisms.
  
  
  RESULTS
  Of the 811 enrolled patients, 291 had acceptable sputum specimens that were included for analysis of the etiologic distribution. With multiplex PCR testing, viruses were identified in 36.1% (105/291), most commonly rhinovirus (25.8%) and coronavirus (3.8%). Typical bacteria were isolated in 126/291 (43.3%) patients. Among these patients Haemophilus influenzae (n = 39) and Streptococcus pneumoniae (n = 30) were isolated most commonly; atypical bacteria were identified in 44 (15.1%) patients. Bacteria-only, virus-only, and mixed infections (bacteria plus virus) accounted for 36.7% (98/291), 17.2% (50/291), and 18.9% (55/291) of infections, respectively. In particular, 52.4% of patients with viral infection had a concurrent bacterial infection, and rhinovirus was the most common virus in mixed infections (40/55). Additionally, infections with typical bacteria were more common in patients with chronic lung disease (p = 0.029), and typical bacterial infections showed a trend towards a higher prevalence with older age (p = 0.001).
  
  
  CONCLUSIONS
  Bacteria were associated with almost half of community-acquired acute bronchitis cases. Additional studies are required to further illuminate the role of bacteria and to identify patient groups most likely to benefit from antibiotic treatment.
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
authors: Ji Young
authors: JY
authors: Park
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
authors: Sunghoon
authors: S
authors: Park
authors: Seegene Medical Foundation, Seoul, Republic of Korea.
authors: Sun Hwa
authors: SH
authors: Lee
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea.
authors: Myung Goo
authors: MG
authors: Lee
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Kangdong Sacred Heart Hospital, Seoul, Republic of Korea.
authors: Yong Bum
authors: YB
authors: Park
authors: Myeongmun Clinic of Internal Medicine, Yongin, Republic of Korea.
authors: Kil Chan
authors: KC
authors: Oh
authors: Leejaemyung Clinic of Internal Medicine, Anyang, Republic of Korea.
authors: Jae-Myung
authors: JM
authors: Lee
authors: Rapha Clinic of Otolaryngology, Anyang, Republic of Korea.
authors: Do Il
authors: DI
authors: Kim
authors: Division of Pulmonary and Critical Care Medicine, Soonchunhyang University Hospital, Cheonan, Republic of Korea.
authors: Ki-Hyun
authors: KH
authors: Seo
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Yeungnam University Medical Center, Daegu, Republic of Korea.
authors: Kyeong-Cheol
authors: KC
authors: Shin
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Konkuk University Hospital, Seoul, Republic of Korea.
authors: Kwang Ha
authors: KH
authors: Yoo
authors: Division of Pulmonary Medicine, Gwangju Christian Hospital, Gwangju, Republic of Korea.
authors: Yongchun
authors: Y
authors: Ko
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
authors: Seung Hun
authors: SH
authors: Jang
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
authors: Ki-Suck
authors: KS
authors: Jung
authors: Division of Pulmonary, Allergy and Critical Care Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
authors: Yong Il
authors: YI
authors: Hwang
mesh_terms: D000208:Acute Disease; D000328:Adult; D001424:Bacterial Infections / Q000382:microbiology*; D001991:Bronchitis / Q000382:microbiology*; D017714:Community-Acquired Infections / Q000382:microbiology*; D006801:Humans; D011446:Prospective Studies; D056910:Republic of Korea