An outbreak of hand, foot, and mouth disease associated with subgenotype C4 of human enterovirus 71 in Shandong, China.
BACKGROUND
An outbreak of hand, foot, and mouth disease (HFMD) included 1149 people in Linyi City, Shandong Province, China, in 2007: three children died.


OBJECTIVE
To characterize the pathogens responsible for this outbreak and to analyze their genetic features.


METHODS
A total of 233 clinical specimens were collected from 105 hospitalized patients, including 11 patients with severe HFMD. Virological investigations (direct RT-PCR, viral isolation and molecular identification) and phylogenetic analysis were performed.


RESULTS
Human enterovirus 71 (HEV71) was the main pathogen that caused this outbreak, based on clinical manifestations, epidemiological data, and laboratory results. Phylogenetic analysis indicated that the Shandong HEV71 isolates belonged to 3 lineages in subgenotype C4. Subgenotype C4 could be further divided into two clusters (C4a and C4b), which corresponded to two time periods. Cluster C4a HEV71 has been the predominant virus circulating in mainland China in the past 5 years.


CONCLUSIONS
The 2007 HFMD outbreak was mainly caused by HEV71 subgenotype C4 with 3 transmission chains. This virus has been continuously circulating in China since 1998. The Shandong strains co-evolved with isolates from other provinces in mainland China and neighboring countries.
Zhang
Yong
Y
National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Xuanwu District, Beijing, PR China.
Tan
Xiao-Juan
XJ
Wang
Hai-Yan
HY
Yan
Dong-Mei
DM
Zhu
Shuang-Li
SL
Wang
Dong-Yan
DY
Ji
Feng
F
Wang
Xian-Jun
XJ
Gao
Yong-Jun
YJ
Chen
Li
L
An
Hong-Qiu
HQ
Li
De-Xin
DX
Wang
Shi-Wen
SW
Xu
Ai-Qiang
AQ
Wang
Zi-Jun
ZJ
Xu
Wen-Bo
WB
D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D004196:Disease Outbreaks; D029821:Enterovirus A, Human / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006232:Hand, Foot and Mouth Disease / Q000453:epidemiology* / Q000821:virology*; D006801:Humans; D007223:Infant; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
D012367:RNA, Viral