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Objective@#To evaluate the epidemiologic characteristics of hand, foot and mouth disease in Zhejiang province between 2009 and 2017, so that scientific evidence could be provided for prevention and control of hand, foot and mouth disease.@*Methods@#Spatial, temporal and population distribution of HFMD was analyzed. Real-time reverse transcription polymerase cain reaction was used to test Enterovirus A71 and Coxsackievirus A16 in samples.@*Results@#Between 2009 and 2017, 1 108 093 HFMD cases were reported in Zhejiang with the prevalence of 226.24/100000; 2010, 2012, 2014 and 2016 had a higher prevalence than other years. Prevalence of HFMD peaked in April-July and September-October. Wenzhou, Taizhou and Ningbo had a higher prevalence than other cities. In total, 69.27% cases were children who were not enrolled in nursery school, and 65.67% were 1-3 years old. Pathogen surveillance showed that EV-A71 decreased in mild cases, whereas other enterovirus increased. However EV-A71 was still predominant in severe and fatal cases (56.0%).@*Conclusions@#Temporal and spatial distribution of HFMD is characteristic in Zhejiang province. EV-A71 predominated in severe cases and fatal cases, while other enterovirus (non-EV-A71, non CV-A16) were the main pathogen for mild cases.
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Objective To develop a multiplex real -time RT -PCR assay for simultaneous detection of enteroviruses and differentiation of EV71 and CA16.Methods Specific primers and probes were designed for enteroviruses,EV71 and CA16.The probes labeled with various fluorescent reporter dyes,and a triplex real -time RT -PCR technique was developed to simultaneously detect these viruses.A total of 91 clinical specimens with suspected HFMD were analyzed by this method.Results This assay could simultaneously detect enterovirus and differentiation of EV71 and CA16,and the sensitivity of the assay was up to 0.1 TCID50 /mL,and only need 2 to 3 hours for completing the detection.A total of 91 clinical specimens were detected by this assay in 28 of the 91(30.77%)specimens contained EV71,9 of the 91(9.89%) contained CA16,and 5 of the 91 (5.49%)contained other enteroviruses.Conclusion This assay would be a useful molecular diagnostic tool for large -scale screening of clinical samples,especially at the peroid of HFMD outbreaks.
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Objective To study the molecular characteristic of norovirus in 3 outbreaks of gastroenteritis in Zhejiang province. Methods During January 2008 and December 2009, fecal specimens of patients were collected from 3 outbreaks of acute viral gastroenteritis. Noroviruses were detected by Real-time RT-PCR. Part of the positive samples were randomly selected and detected by RT-PCR. PCR products were sequenced. Sequence analysis was undertaken based on partial sequence of RNA dependent RNA polymerase(RdRp)and capsid protein gene. Some positive samples were amplified by 3' RACE(rapid amplification of cDNA 3' ends), 3200 bp in length. The exact whole ORF2, ORF3 and 3' untranslation regions(UTR)gene of norovims were identified. Results There were in total 3 outbreaks of viral gastroenteritis caused by norovirus being reported. A total of 62 stools were obtained from cases with acute gastroentefitis. Noroviruses were detected in 41 cases including 27 strains of genogroup Ⅰ norovirus and 9 strains of genogroup Ⅱ norovirus, 5 strains of genogroup Ⅰ + Ⅱ norovirus. Four genotypes including G Ⅰ .8, G Ⅱ .b, G Ⅰ .2/0 Ⅰ .6 recombination together with co-infection of G Ⅰ .8 and G Ⅱ .b were detected. Conclusion Norovirus was confirmed as the major cause of outbreaks of viral gastroenteritis in Zhejiang province and multiple genotype of norovirus were identified from the outbreaks. It was the first time to have found a recombinant of G Ⅰ .6 capsid and G Ⅰ .2 polymerase norovims as well as the co-infection of G Ⅰ .8 and G Ⅱ .b norovirus in the same sample.
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Objecfive To study the molecular epidemioiogical characteristics of Norovirus gastroenteritis outbreaks in Zhejiang.Methods During January 2006 and December 2007.fecal specimens of patients collected from outbreaks of acute viml gastroenteritis were tcsted for Norovirus.Epidemiological data were also collected.Noroviruses were detected by a reverse transcription polymerase chain reaction(RT-PeR)and Real.time RT-PCR.Some positive samples were randomly selected and Rrr-PCR products were sequenced.Comparing to the nucleotide sequences of norovirus genotype Ⅰ,Ⅱ reference strains from GenBank,sequence analysis was undertaken based on partial sequence of RNA dependent RNA polymerase(RdRp)and capsid protein(VPI)gene.Results 5 Outbreaks of viral gastroenteritis caused bv Norovirus were reported.A total of 63 stools were obtained from cases with acute gastroenteritis.Noroviruses alone were detected in 45 cases and the illness appeared in autumn.Phylogenetic analysis revealed that Norovirus belonged to G Ⅱ/G Ⅱ 4 type.The strains isolated from Zhejiang were almost identical on G Ⅱ/4 variants that causing epidemics in Beijing and in the Netherlands with the homology of 99.7%and 98.5%-99.O%respectively.Phylogenetic analysis revealed that the isolates were located at the same branch as the norovirus G Ⅱ/4 variants found in Beijing and Netherlands.Conclusion Norovirus iS a major cause of outbreaks of viral gastroenterifis in Zhejiang province.GenogroupⅡ/4 variants viruses were the prevalent strains.
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<p><b>OBJECTIVE</b>To study the gene characterization of enterovirus 71 (EV71) virus strains isolated from clinical specimens of children with hand-foot-and-mouth disease (HFMD) in Zhejiang province.</p><p><b>METHODS</b>Virus were isolated from clinical samples including stool, throat swab and vesicle from patients with HFMD. The EV71 isolates were identified by microneutralization assay and reverse transcriptase PCR (RT-PCR) with specific primer pair for VP1 genes of EV71. Complete VP1 gene sequences (891 nucleotides) for recent 6 EV71 isolates were determined and compared with that of A, B, C genotype reference EV71 strains and 11 EV71 China isolates available from GeneBank by homogeneity and phylogenetic tree analyses.</p><p><b>RESULTS</b>9 strains of EV were isolated from 14 clinical specimens. Data from microneutralization and RT-PCR results indicated that all the strains belong to EV71. The nucleotide and amino acid homogeneity of these 6 Zhejiang strains with the representative isolates of A and B genotypes were 82.9%-85.5% and 94.9%-98.0% respectively; with the representative isolates of C were 89.2%-94.1% and 97.0%-99.0% respectively. There were 91.0%-92.2%, 90.2%-90.3%, 89.2%-89.5%, 96.7%-96.9% nucleotide, homology with representative strains of C1, C2, C3,C4 subgenotypes of EV71. The nucleotide homogeneity of these 6 EV71 isolated strains with 9 previously isolated Chinese strains appeared to be 93.8%-97.1%. These 6 EV71 isolated strains were within genotype C subgenogroup C4 in the phylogenetic tree.</p><p><b>CONCLUSION</b>The recently identified EV71 isolates in Zhejiang province belonged to subgenogroup C4.</p>