title: Emergence of serogroup C meningococcal disease associated with a high mortality rate in Hefei, China.
abstract: BACKGROUND
  Neisseria meningitidis serogroup C has emerged as a cause of epidemic disease in Hefei. The establishment of serogroup C as the predominant cause of endemic disease has not been described.
  
  
  METHODS
  We conducted national laboratory-based surveillance for invasive meningococcal disease during 2000-2010. Isolates were characterized by pulsed-field gel electrophoresis and multilocus sequence typing.
  
  
  RESULTS
  A total of 845 cases of invasive meningococcal disease were reported. The incidence increased from 1.25 cases per 100,000 population in 2000 to 3.14 cases per 100,000 in 2003 (p < 0.001), and peaked at 8.43 cases per 100,000 in 2005. The increase was mainly the result of an increase in the incidence of serogroup C disease. Serogroup C disease increased from 2/23 (9%) meningococcal cases and 0.11 cases per 100,000 in 2000 to 33/58 (57%) cases and 1.76 cases per 100,000 in 2003 (p < 0.01). Patients infected with serogroup C had serious complications more frequently than those infected with other serogroups. Specifically, 161/493 (32.7%) cases infected with serogroup C had at least one complication. The case-fatality rate of serogroup C meningitis was 11.4%, significantly higher than for serogroup A meningitis (5.3%, p = 0.021). Among patients with meningococcal disease, factors associated with death in univariate analysis were age of 15-24 years, infection with serogroup C, and meningococcemia.
  
  
  CONCLUSIONS
  The incidence of meningococcal disease has substantially increased and serogroup C has become endemic in Hefei. The serogroup C strain has caused more severe disease than the previously predominant serogroup A strain.
authors.affiliation: Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
authors.forename: Xi-Hai
authors.initials: XH
authors.lastname: Xu
authors.forename: Ying
authors.initials: Y
authors.lastname: Ye
authors.forename: Li-Fen
authors.initials: LF
authors.lastname: Hu
authors.forename: Yu-Hui
authors.initials: YH
authors.lastname: Jin
authors.forename: Qin-Qin
authors.initials: QQ
authors.lastname: Jiang
authors.forename: Jia-Bin
authors.initials: JB
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality*; D008875:Middle Aged; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D038542:Neisseria meningitidis, Serogroup C / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D016019:Survival Analysis; D055815:Young Adult