title: Epidemiology and associations with climatic conditions of Mycoplasma pneumoniae and Chlamydophila pneumoniae infections among Chinese children hospitalized with acute respiratory infections.
abstract: BACKGROUND
  The incidence of severe acute respiratory tract infections in children caused by Mycoplasma pneumoniae (syn. Schizoplasma pneumoniae) and Chlamydophila pneumoniae (formerly Chlamydia pneumoniae) varies greatly from year to year and place to place around the world. This study investigated the epidemiology of M. pneumoniae and C. pneumoniae infections among children hospitalized with acute respiratory infections in Suzhou, China in the year 2006, and associations between incidence rates and climatic conditions.
  
  
  METHODS
  Nasopharyngeal aspirates obtained from 1598 patients (aged 26.4 ± 28.3 months; range, 1 month to 13 years) were analyzed with real-time PCR and ELISA. Meteorological data were obtained from the weather bureau.
  
  
  RESULTS
  About 18.5% of patients were infected with M. pneumoniae and, C. pneumoniae, or both. Isolated M. pneumoniae infection was positively correlated with increasing age (χ² = 34.76, P < 0.0001). Incidence of M. pneumoniae infection was seasonal with a peak in summer (P < 0.0001) and minimum in winter (P = 0.0001), whereas C. pneumoniae infection was low only in autumn (P = 0.02). Monthly mean temperature was strongly correlated with the incidence of M. pneumoniae infection (r = 0.825, P = 0.001).
  
  
  CONCLUSIONS
  M. pneumoniae and C. pneumoniae are important infectious agents in hospitalized children with acute respiratory tract infections. M. pneumoniae infection showed a strong direct correlation with environmental temperature.
authors.affiliation: Department of Respiratory Disease, Children's Hospital Affiliated to Soochow University, No. 303 JingDe Road, Suzhou, Jiangsu Province 215003, China. szdxjiwei@163.com
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Ji
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wang
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Yan
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.forename: Xuejun
authors.initials: X
authors.lastname: Shao
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D023521:Chlamydophila Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology*; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007297:Inpatients / Q000706:statistics & numerical data*; D008297:Male; D009177:Mycoplasma pneumoniae / Q000302:isolation & purification*; D011019:Pneumonia, Mycoplasma / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology*; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology; D012621:Seasons