Analysis the viral etiology of fever and respiratory tract infection syndrome in Shaanxi province / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Analysis the viral pathogenic spectrum for patients with fever and respiratory tract infection syndrome in Shaanxi province during 2010 and investigate the molecular epidemiology characteristics of respiratory syncytial virus.</p><p><b>METHODS</b>A total of 208 patients' pharyngeal swabs were collected based on surveillance definition from January 2010 to January 2011 and screened for sixteen human respiratory virus types/subtypes by Qiaxcel-based multiplex reverse transcription-PCR assay, including HRV,HCoV, Flu, HPIV, ADV, HRSV, HMPV and HBoV and investigate molecular epidemiology of HRSV by sequencing and phylogenetic analysis of the C-terminal second hypervariable region of the G gene.</p><p><b>RESULTS</b>109 out of 208 specimens (53%) were positive for one or more viruses. HRSV(42. 2%) was the dominant pathogen detected, followed by Flu(24. 5%), PIV(20%), HRV(13.6%) and ADV( 10.9%),there were also 8 strains of HCoV, 5 strains of HMPV and 3 strains of HBoV detected. The results showed that 22 specimens were positive for two or more viruses, PIV (14/22) was the most frequently detected viral agent among co-infection specimens, and the highest incidence of mixed infection is aged 15-39 years group (P < 0.05). The overall viral detection rate was no related to age. In addition to Flu, HMPV and PIV, other viruses (HRV, HBoV, HCoV, ADV, RSV) mainly infected 0 to 4 years old children. Among 46 HRSV positive specimens, 42 HRSV-A strains clustered into NA1 genotype and two HRSV-B strains clustered into two genotypes, BA9 and GB2.</p><p><b>CONCLUSION</b>HRSV is the dominate pathogen collected from patients with fever and respiratory tract infection syndrome in Shaanxi and HRSV A is the predominant subtype. For most viruses, infection was most prevalent among children aged <4 years. PIV was the most common pathogen in co-infection.</p>

Analysis of genetic characteristics of type II non-wild poliovirus in mainland China, 2010 / 病毒学报

To study the genetic characteristics of 123 type II non-wild polioviruses isolated from acute flaccid paralysis (AFP) cases in mainland China in 2010, provide the scientific basis for maintaining the "polio-free" status, and the switching use of polio vaccine for China. VP1 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and the PCR products were then sequenced. The sequence results were analyzed with Sequencher 4.8, BioEdit 7.0.9 and MEGA 5.0. Of 65 strains, nt2909 was found to be a mutation hotspot, and also a neurovirulence determinant in VP1 region. During 2010, two vaccine-derived polioviruses (VDPVs) were isolated from Yunnan province, China and no wild poliovirus (WPV) was isolated. The epidemiological studies and laboratory results of the two VDPVs showed that they were newly discovered VDPVs because of the genetic difference from other VDPVs strains isolated in the world, implying the sensitive poliovirus surveillance network could timely detect the transmission of VDPVs and the importation of WPV.

Ananlysis on the molecular characteristics of CVA9 virus in Tibet / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the molecular characterization of CVA9 virus in Tibet.</p><p><b>METHODS</b>To isolate the enteroviruses from stool specimens of AFP cases and other children in Tibet in 1999-2002, and identify them by neutralization test using the RIVM antiserum; then determine the complete nucleotide sequence of VP1 region of CVA9 viruses, and analyze the results.</p><p><b>RESULTS</b>A total of 10 strains of CVA9 virus were isolated from the stool specimens and identified. The complete nucleotide sequence of VP1 region of these CVA9 viruses were 906nt coding 302 amino acids. To compare with the sequences of the 10 strains of Tibet, the homogeneity of nucleotide sequence were 79.0% - 99.9%; while they were 75.7% - 78.7% compared with Griggs. The phylogenetic tree of CVA9 viruses showed 2 groups, and the isolates from Tibet belong to 1, 2 groups.</p><p><b>CONCLUSION</b>The deduction is that the 10 strains are proposed 2 different groups, the strains epidemic in 1999 belong to group 2,while strains in 2000 belong to group 1.</p>

The first imported measles case associated with genotype D4 measles virus in China / 病毒学报

This study reported the first imported measles case associated with genotype D4 measles virus in Shanxi province in China. The clinical specimen of throat swab was inoculated into Vero/SLAM culture to isolate the virus. A RT-PCR (Reverse transcription polymerase chain reaction, RT-PCR) was performed to amplify the 676 nucleotides sequence corresponding to the carboxyl terminus of measles virus nucleoprotein. The phylogenetic tree based on the 450 nucleotide acids of carboxyl terminus of N protein was constructed and the homology similarity was analyzed. The Shanxi isolate MVi/Shanxi. CHN/20. 09/1 was clustered within the same genotype group with WHO genotype D4 reference strain, Montreal. CAN/89, and the homology of nucleotide acid between Shanxi isolate and WHO genotype D4 reference strain was 97.3%. The homology of nucleotide acid and amino acid between Shanxi isolate and 2009 genotype D4 representative strain circulating in USA, Canada, India and Russian were 98.0%-100% and 97.3%-100%, respectively. These results showed that the virus isolated from the imported measles case was genotype D4. This is the first report that the genotype D4 measles virus was imported and isolated in China. It is important to accumulate baseline data of China and help to measure transmission pathways and to clarify epidemiological links.

Genetic characterization of the N protein of subgroups A and B human respiratory syncytial viruses / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To clarify the genetic characteristics of N protein coding region of HRSV isolates from Beijing and GenBank downloaded sequences.</p><p><b>METHODS</b>Reverse transciption polymerase chain reaction (RT-PCR) was performed to amplify the N protein gene of 2 A and 2 B subgroups HRSV isolates from Beijing in the year 2004. The RT-PCR products were sequenced for N protein coding region. The sequences of N protein coding region of 4 Beijing isolates and those downloaded from GenBank were compared and analyzed.</p><p><b>RESULTS</b>The differences in number of nucleotide and deduced amino acid between 2 A Beijing 2004 isolates and prototype strain Long were 36-40 (3.1%-3.4%) and 4 (1.0%). The differences in number of nucleotide and deduced amino acid between 2 B Beijing 2004 isolates and prototype strain CH18537 were 17 (1.4%) and 1 (0.3%). The differences in number of nucleotide and deduced amino acid were 3-172 (0.25%-14.63%) and 0-18 (0-4.6%) respectively between 4 Beijing 2004 isolates and GenBank sequences.</p><p><b>CONCLUSION</b>N gene is the highly conservative gene in the HRSV genome. The variation between A and B subgroups were widely distributed in the entire gene of N protein, while the variation within the A or B subgroups HRSV was considerably lower.</p>