title: Etiology of acute lower respiratory tract infection in Central Australian Aboriginal children.
abstract: BACKGROUND
  Aboriginal children in central Australia have attack rates for acute lower respiratory tract infection (ALRI) that are similar to those in developing countries. Although mortality rates are much lower than in developing countries, morbidity is high and ALRI is still the leading cause of hospitalization. However, there are no data on the etiology of ALRI in this population.
  
  
  METHODS
  We prospectively studied 322 cases of ALRI in 280 Aboriginal children admitted to the hospital. Blood, urine and nasopharyngeal aspirate samples were examined for evidence of bacterial, viral and chlamydial infection.
  
  
  RESULTS
  The combination of blood culture, viral studies and chlamydial serology provided at least 1 etiologic agent in 170 of 322 (52.5%) cases. Assays for pneumolysin immune complex and pneumolysin antibody increased etiologic diagnosis to 219 (68.0%). Blood cultures were positive in 6% but pneumolysin immune complex and pneumolysin antibody studies were positive in one-third of cases. Evidence of viral infection was present in 155 (48%) of cases compared with 12% in controls (P < 001). There were only 7 possible cases and 2 definite cases of Chlamydia trachomatis and 3 cases of Chlamydia pneumoniae. Coinfection was common in these children.
  
  
  CONCLUSIONS
  These findings have implications for both standard treatment protocols and vaccine strategies. The high rate of coinfection may make it difficult to develop simple clinical predictors of bacterial infection. In the setting of a developed country with efficient patient evacuation services, management algorithms that focus on disease severity and need for hospital referral will be most useful to health staff in remote communities. Pneumococcal conjugate vaccines will be required to reduce the high attack rate of pneumococcal disease.
authors.affiliation: Queensland Institute of Medical Research, Brisbane, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Torzillo
authors.forename: J
authors.initials: J
authors.lastname: Dixon
authors.forename: K
authors.initials: K
authors.lastname: Manning
authors.forename: S
authors.initials: S
authors.lastname: Hutton
authors.forename: M
authors.initials: M
authors.lastname: Gratten
authors.forename: L
authors.initials: L
authors.lastname: Hueston
authors.forename: M
authors.initials: M
authors.lastname: Leinonen
authors.forename: F
authors.initials: F
authors.lastname: Morey
authors.forename: S
authors.initials: S
authors.lastname: Forsythe
authors.forename: R
authors.initials: R
authors.lastname: Num
authors.forename: J
authors.initials: J
authors.lastname: Erlich
authors.forename: V
authors.initials: V
authors.lastname: Asche
authors.forename: A
authors.initials: A
authors.lastname: Cunningham
authors.forename: I
authors.initials: I
authors.lastname: Riley
mesh_terms: D001315:Australia / Q000453:epidemiology; D001419:Bacteria / Q000302:isolation & purification; D001424:Bacterial Infections / Q000208:ethnology* / Q000382:microbiology; D001426:Bacterial Proteins; D002675:Child, Preschool; D002689:Chlamydia / Q000302:isolation & purification; D002690:Chlamydia Infections / Q000208:ethnology / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000208:ethnology / Q000382:microbiology* / Q000821:virology; D013048:Specimen Handling / Q000379:methods; D013301:Streptolysins / Q000032:analysis; D014777:Virus Diseases / Q000208:ethnology* / Q000821:virology; D014780:Viruses / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D013301:Streptolysins; C032290:plY protein, Streptococcus pneumoniae