Identification of a new Neisseria meningitidis serogroup C clone from Anhui province, China.
BACKGROUND
Outbreaks of a new serogroup C meningococcal disease emerged during 2003-04 (five outbreaks with 43 cases) and in 2004-05 (five outbreaks with 29 cases), all in Anhui province, China. We describe the molecular epidemiology and features of the causative bacterial strains.


METHODS
We used pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) to analyse the strains.


RESULTS
Of 34 strains of Neisseria meningitidis cultured during 2003-04 from Anhui province, 31 were group C meningococci, 28 of which were associated with three of five outbreaks; one from a patient and 27 from close contacts of eight patients. Of 30 strains isolated from Anhui province during 2004-05, 17 were identified as serogroup C meningococci, ten of which were associated with four of five outbreaks. In a nationwide survey, 542 strains were isolated during 2004-05; 58 were serogroup C meningococci interspersed among 11 other provinces where no serogroup C outbreak occurred. Of the 106 serogroup C strains analysed, 89 had identical PFGE patterns, designated AH1. Of 28 strains selected for MLST analyses, 25 were sequence type 4821 (ST-4821), which did not belong to any of the previously reported sequence types that can form a new hypervirulent lineage.


CONCLUSIONS
ST-4821 seems to be unique and caused the serogroup C meningitis outbreaks during the two seasons from 2003 to 2005 in Anhui province. The emergence of this sequence type has epidemiological importance that should be monitored for future spread in China and the rest of the world.
Shao
Zhujun
Z
National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), PO Box 5, Changping, Beijing 102206, China.
Li
Wei
W
Ren
Jun
J
Liang
Xiaofeng
X
Xu
Li
L
Diao
Baowei
B
Li
Machao
M
Lu
Meijuan
M
Ren
Hongyu
H
Cui
Zhigang
Z
Zhu
Bingqing
B
Dai
Zhenwei
Z
Zhang
Li
L
Chen
Xia
X
Kan
Biao
B
Xu
Jianguo
J
D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D017720:Molecular Epidemiology; D038542:Neisseria meningitidis, Serogroup C / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity; D014611:Vaccination