[Association between hand-foot-and-mouth disease in Xi'an and enterovirus 71].
OBJECTIVE
To isolate the prevalent strain of enterovirus 71 (EV71) in Xi'an area in 2008, and compare the concordance of viral isolation, reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescent technique in detecting EV71, find the fast and effective method for detection, and analyze the differences between the EV71 strains isolated from Xi'an and Fuyang, Anhui.


METHODS
Virus isolation and RT-PCR were carried out on vesicle fluid and throat swab specimens that were collected from the patients with hand-foot-and-mouth disease, RD and HEp-2 cell lines were used for viral isolation. The virus was identified by using immunofluorescence technique. Nucleotide sequencing was performed on positive product of RT-PCR, and compared with EV71 isolated from Fuyang in 2008, then submitted to Genbank.


RESULTS
Among the 56 samples of throat swab inoculated on RD and HEp-2 cells, the positive rates were 5.4% (3/56) and 1.8% (1/56), respectively. Among the 56 samples of vesicle fluid inoculated on RD and HEp-2 cells, the positive rates were 12.5% ( 7/56 ) and 5.4% (3/56), respectively. Cytopathic effect of RD and HEp-2 cells appeared on days 7 and 10, respectively. The positive rates of RT-PCR on throat swab and vesicle fluid samples were 21.4% (12/56) and 33.9% (19/56), respectively. Cytopathic effect was found in cell culture for 14 cases and immunofluorescence, showed that 9 of them were infected with EV71. The authors obtained the EV71 strain prevalent in Xi'an during 2008. The nucleotide sequence was submitted to the NCBI Genbank and gained the accession number EU812461.


CONCLUSIONS
The EV71 in Xi'an prevalent during 2008 may have a weaker epithelial tropism. Comparison of the EV71 strain isolated from Xi'an with EU703812, EU703813 and EU703814 isolated from Fuyang, Anhui showed that the homology was 97%-98%. RT-PCR is an important method for rapid detection of EV71.
Nie
Xiao-Jing
XJ
Department of Pediatrics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
Zhang
Xue-Hong
XH
Zhang
Guo-Cheng
GC
Xu
Dong-Liang
DL
Ma
Chao-Feng
CF
Li
Ya-Rong
YR
Sun
Xin
X
Li
Xiao-Qing
XQ
D012634:Bodily Secretions / Q000821:virology; D045744:Cell Line, Tumor; D002648:Child; D002681:China / Q000453:epidemiology; D029821:Enterovirus A, Human / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D006232:Hand, Foot and Mouth Disease / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D008969:Molecular Sequence Data; D010614:Pharynx / Q000821:virology; D012367:RNA, Viral; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid
D012367:RNA, Viral