[Etiology surveillance of hand-foot-mouth disease in Henan province between 2008 and 2011].

OBJECTIVE: To understand etiological types and distribution features of hand-foot-mouth disease (HFMD) in Henan province between 2008 and 2011. METHODS: A total of 30 486 specimens of feces, rectal swabs or throat swabs from HFMD patients were collected by each Municipal CDC in Henan from 2008 to 2011. The enterovirus 71 (EV71), coxsackie virus A16 (CA16) and other enterovirus (EV) were detected by RT-PCR or real time RT-PCR. The VP1 gene of EV71 was amplified and the sequences were analyzed by bioinformatics software. A genetic evolution tree of the sequence was constructed as well. RESULTS: The positive rates of EV71, CA16 and other EV were 62.70% (11 209/17 876), 12.03% (2150/17 876), 25.27% (4517/17 876) in 17 876 laboratory diagnosed cases, respectively. The differences were statistically significant (χ(2) = 157.17, P < 0.05). The positive rates of EV71, CA16 and other EV were 63.40% (7370/11 624), 11.58% (1346/11 624) and 25.02% (2908/11 624) in male patients and 61.40% (3839/6252), 12.86% (804/6252) and 25.74% (1609/6252) in female patients, respectively. The differences were statistically significant (χ(2) = 4.06, P < 0.05). The children under 5 years old were high-risk population of HFMD, accounting to 97.67% (17 459/17 876) of the laboratory-diagnosed patients.86.92% (15 537/17 876) cases were children between 1 to 3 years old. Constituent ratio of EV71 changed seasonally during a year, there was a high infection ratio of EV71 between April and June, especially in May, the infection ratio reached 69.34% (2384/3438). The positive rates of EV71, CA16 and other EV were 82.48% (5715/6929), 1.76% (122/6929) and 15.76% (1092/6929) among the 6929 laboratory-diagnosed severe cases, respectively. The positive rates of EV71 was higher than CA16 and other EV (χ(2) = 9259.17, 6170.81, P < 0.05, respectively). There were 117 deaths because of severe HFMD, 55 (47.01%) of which were laboratory confirmed. 50 death cases were infected by EV71, and according to the genetic evolution analysis, the VP1 gene of EV71 strain was belonged to subtype C4 of gene C. CONCLUSION: The EV71 and CA16 were the main pathogens which caused HFMD in Henan province, and EV71 virus was the dominant strain, belonging to C4 subtype of gene C.

[Complete genome sequencing of enterovirus 71 (EV71) HENAN08 strain isolated in Henan province].

OBJECTIVE: To sequence the whole-genome of enterovirus 71 (EV71) srtain isolated from patient with hand, foot and mouth in Henan province in 2008. METHODS: Eight overlapping clones covering the whole viral genome were obtained by RT-PCR and the sequences were determined by Sanger dideoxg-mediated chain termination method. RESULTS: Data it showed that the full length of enterovirus 71 (EV71) HENAN08 genome (not including Poly A tail) is 7405 bp. No deletion or insertion was detected in the coding region. There were several deletions and insertions in 5'UTR and 3'UTR regions. In P1 region, HENAN08 strain shared high homology with AnhuiFY08 strain, Zhejiang08 strain and SHZH strains (SHZH98, SHZH03) but low homology with Cox. A16. In P2 and P3 regions, HENAN08 strain shared higher nucleotide homology with Cox. A16 (81.7% and 83.7%) than that with BrCr and TW2086 strains. The phylogenetic analysis based on P1 region demonstrates that HENAN08 strain had the nearest genetic relationship with AnhuiFY and Zhejiang strains (isolated in 2008). CONCLUSION: The HENAN08 strain might belong to the same genogroup with AnhuiFY08 and Zhejiang08 strains as C4 gene subtypes.