title: [Investigation on the carrier for Haemophilus influenzae in healthy population in Shenzhen].
abstract: OBJECTIVE
  To Investigate the rate of carrying virus of Haemophilus influenzae in population of Shenzhen.
  
  
  METHODS
  Cross-sectional study was applied and 380 samples were recruited by cluster sampling in April to July 2008. The identification of H. influenzae strains were done according to the loboratory standard methodology described by Manual of Clinical Microbiology (American). All strains were biotyped according to Kilian's classification with the API NH system. And serotyped by a slide agglutination assay with type to a specific antiserum as described by Pittman. PCR method for identification of H. infiuenzae were performed as described by Falla.
  
  
  RESULTS
  The rate of carrying Haemophilus influenzae in population was 31.84% (121/380). The rate of 6-year groups was the highest (54.90%). The rate of 50-year groups was the lowest (8.51%). The rate of carrying Haemophilus influenzae had significant difference by age groups (chi2 = 30.172 P < 0.005). Eight biotypes were found among the 139 H. influenzae isolates. 7.91% (11/139) of all isolates belonged to biotype I, 37.41% (52/139) were biotype II, 34.53% (48/139) were biotype III, 4.32% (6/139) were biotype IV, 7.91% (11/139) were biotype V, 0.72% (1/139) were biotype VI, 6.47% (9/139) were biotype VII and 0.72% (1/139) were biotype VIII respectively. 97.14% (170/175) were nontypeable. There were five isolates were typeable. Two were serotype b. Three were serotype e. The rate of producing beta-lactamase was 14.38% (20/139).
  
  
  CONCLUSIONS
  The rate of carrying Haemophilus influenzae in healthy population of Shenzhen was high. The main isolates were type II and III. And the isolates were nontypeable H. influenzae primarily.
authors.affiliation: Center for Disease Control and Prevention in Nanshan District of Shenzhen, Shenzhen 518054, Guangdong, China.
authors.forename: Qun-Wen
authors.initials: QW
authors.lastname: Wen
authors.forename: Guo-Zhong
authors.initials: GZ
authors.lastname: Tian
authors.forename: Zhou-Ning
authors.initials: ZN
authors.lastname: Yan
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002353:Carrier State / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D006193:Haemophilus influenzae / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012703:Serotyping; D055815:Young Adult