关键词： 脊髓灰质炎疫苗   脊髓灰质炎灭活疫苗   接种   云南  

摘要： 目的:分析云南省昆明市五华区及丽江市脊髓灰质炎疫苗(PV)接种情况及脊髓灰质炎灭活疫苗(IPV)在每个剂次中所占的比率及普及情况。方法:从两地疾病预防控制中心儿童免疫规划信息管理系统中收集2016年5月～2017年7月儿童PV接种数据,应用描述性流行病学方法进行分析。结果:2016年5月～2017年7月,五华区共接种PV 65 349剂,每一剂接种率均为99%以上,第1、2、3及4次剂IPV所占比率分别为86. 02%、33. 62%、26. 30%及20. 33%;丽江市共接种脊髓灰质炎疫苗21 962剂,每一剂次接种率均为99%以上,第1、2、3及4次剂IPV所占比率分别为39. 75%、7. 55%、8. 20%及0. 07%,使用IPV种类多为Sabin-IPV、Salk-IPV、DTa P-IPV/Hib,DTa P-IPV/Hib所占比率最高(62. 63%,χ~2=9 597. 6,P <0. 001);丽江市IPV相对单一,95%为免费Sabin-IPV,五华区IPV接种率明显高于丽江市(χ~2=22 614. 9,P <0. 001)。结论:昆明市五华区IPV接种率明显高于丽江市。

关键词： 脊髓灰质炎病毒   非脊灰肠道病毒   病原学监测  

摘要： 目的通过对青海省2013-2017年急性驰缓性麻痹(Acllte flaccid paralysis,AFP)病例与健康人群的病原学进行监测,为维持无脊灰状态提供准确、可靠的科学依据。方法采用RD、L20B细胞对AFP病例及健康人群的粪便标本进行病毒分离,分离到的脊髓灰质炎毒株送至国家脊髓灰质炎实验室进行鉴定。结果 2013-2017年共接收AFP病例粪便标本106份,分离到脊髓灰质炎病毒(Poliovirus,PV) 1株,分离率为0. 94%,分离到非脊灰肠道病毒(NonPolio Enterovirus,NPEV) 11株,分离率为10. 38%。共接收全省健康人群粪便标本790份,分离到PV 6株,分离率为0. 76%,分离到NPEV 143株,分离率为18. 10%。AFP病例及健康人群标本中分离到的所有PV毒株中,PVⅠ型5株,PVⅢ型1株,PVⅠ+PVⅢ混合型1株,均为脊灰疫苗相关株,无脊灰野病毒株。结论青海省2013-2017年无本地脊灰野毒株病例流行,阻断了脊灰本地野病毒的传播,保持了无脊灰状态。

关键词： bacteria   poliovirus   stability  

摘要： Enteric viruses, including poliovirus, are spread by the fecal-oral route. In order to persist and transmit to a new host, enteric virus particles must remain stable once they are in the environment. Environmental stressors such as heat and disinfectants can inactivate virus particles and prevent viral transmission. It has been previously demonstrated that bacteria or bacterial surface glycans can enhance poliovirus virion stability and limit inactivation from heat or bleach. While investigating the mechanisms underlying bacterially enhanced virion thermal stability, we identified and characterized a poliovirus (PV) mutant with increased resistance to heat inactivation. The M132V mutant harbors a single amino acid change in the VP1 capsid coding that is sufficient to confer heat resistance but not bleach resistance. Although the M132V virus was stable in the absence of bacteria or feces at most temperatures, M132V virus was stabilized by feces at very high temperatures. M132V PV had reduced specific infectivity and RNA uncoating compared with those of wild-type (WT) PV, but viral yields in HeLa cells were similar. In orally inoculated mice, M132V had a slight fitness cost since fecal titers were lower and 12.5% of fecal viruses reverted to the WT. Overall, this work sheds light on factors that influence virion stability and fitness. IMPORTANCE Viruses spread by the fecal-oral route need to maintain viability in the environment to ensure transmission. Previous work indicated that bacteria and bacterial surface polysaccharides can stabilize viral particles and enhance transmission. To explore factors that influence viral particle stability, we isolated a mutant poliovirus that is heat resistant. This mutant virus does not require feces for stability at most temperatures but can be stabilized by feces at very high temperatures. Even though the mutant virus is heat resistant, it is susceptible to inactivation by treatment with bleach. This work provides insight into how

关键词： 2A(pro)   cleavage   evolution   poliovirus   selection  

摘要： Virus capsid proteins must perform a number of roles. These include self-assembly and maintaining stability under challenging environmental conditions, while retaining the conformational flexibility necessary to uncoat and deliver the viral genome into a host cell. Fulfilling these roles could place conflicting constraints on the innate abilities encoded within the protein sequences. In a previous study, we identified a number of mutations within the capsid-coding sequence of poliovirus (PV) that were established in the population during selection for greater thermostability by sequential treatment at progressively higher temperatures. Two mutations in the VP1 protein acquired at an early stage were maintained throughout this selection procedure. One of these mutations prevented virion assembly when introduced into a wild-type (wt) infectious clone. Here we show, by sequencing beyond the capsid-coding region of the heat-selected virions, that two mutations had arisen within the coding region of the 2A protease. Both mutations were maintained throughout the selection process. Introduction of these mutations into a wt infectious clone by site-directed mutagenesis considerably reduced replication. However, they permitted a low level of assembly of infectious virions containing the otherwise lethal mutation in VP1. The 2A(pro) mutations were further shown to slow the kinetics of viral polyprotein processing, and we suggest that this delay improves the correct folding of the mutant capsid precursor protein to permit virion assembly. IMPORTANCE RNA viruses, including poliovirus, evolve rapidly due to the error-prone nature of the polymerase enzymes involved in genome replication. Fixation of advantageous mutations may require the acquisition of complementary mutations which can act in concert to achieve a favorable phenotype. This study highlights a compensatory role of a nonstructural regulatory protein, 2A(pro), for an otherwise lethal mutation of the structural VP1 pro

关键词： Environmental surveillance   Skimmed-milk flocculation   Wastewater   Enteric viruses   Poliovirus  

摘要： Effective surveillance of human enteric viruses is critical to estimate disease prevalence within a community and can be a vital supplement to clinical surveillance. This study sought to evaluate simple, effective, and inexpensive secondary concentration methods for use with ViroCap (TM) filter eluate for environmental surveillance of poliovirus. Wastewater was primary concentrated using cartridge ViroCap filters, seeded with poliovirus type 1 (PV1), and then concentrated using five secondary concentration methods (beef extract-Celite, ViroCap flat disc filter, InnovaPrep (R) Concentrating Pipette, polyethylene glycol [PEG]/sodium chloride [NaCl] precipitation, and skimmed-milk flocculation). PV1 was enumerated in secondary concentrates by plaque assay on BGMK cells. Of the five tested methods, PEG/NaCl precipitation and skimmed-milk flocculation resulted in the highest PV1 recoveries. Optimization of the skimmed-milk flocculation method resulted in a greater PV1 recovery (106 +/- 24.8%) when compared to PEG/NaCl precipitation (59.5 +/- 19.4%) (p=0.004, t-test). The high PV1 recovery, short processing time, low reagent cost, no required refrigeration, and requirement for only standard laboratory equipment suggest that the skimmed-milk flocculation method would be a good candidate to be field-validated for secondary concentration of environmental ViroCap filter samples containing poliovirus.

关键词： Blood group   FUT2   immunogenicity   OPV   poliovirus   secretor   vaccine  

摘要： FUT2 determines whether histo-blood group antigens are secreted at mucosal surfaces. Secretor status influences susceptibility to enteric viruses, potentially including oral poliovirus vaccine (OPV). We performed a nested case-control study to determine the association between FUT2 genotype (single-nucleotide polymorphisms G428A, C302T, and A385T) and seroconversion among Indian infants who received a single dose of monovalent type 3 OPV. Secretor prevalence was 75% (89 of 118) in infants who seroconverted and 80% (97 of 122) in infants who did not seroconvert (odds ratio, 0.79;95% confidence interval, .43-1.45). Our findings suggest that FUT2 genotype is not a key determinant of variation in OPV immunogenicity.

摘要： The article offers information on the circulating vaccine-derived poliovirus type 1 and outbreak response in the Papua New Guinea in 2018. Topics discussed include information on the Papua New Guinea was at risk for delayed detection of poliovirus due to insufficient surveillance system for acute flaccid paralysis and delays in seeking health care; discussions on the need to receive a single, lifetime adult booster of polio vaccine by the adults and children.

关键词： 脊髓灰质炎病毒   细胞系敏感性实验  

摘要： 目的评估福建省脊髓灰质炎(脊灰)实验室所用细胞系对脊灰病毒的敏感性,为维持无脊灰工作提供可靠的质量保证。方法采用96孔微量培养板滴定法测定国家脊灰实验室提供的人横纹肌肉瘤细胞(RD)和转人脊灰病毒受体的小鼠肺细胞系(L20B)对福建省脊灰实验室质量控制(Laboratory qualitycontrol,LQC)株Ⅰ、Ⅱ、Ⅲ型发生细胞病变(cytopathic effect,CPE)对应的病毒稀释度,使用Karber公式计算病毒滴度。结果福建省脊灰实验室2013～2018年细胞系敏感性的实验结果显示RD和L20B细胞对脊灰病毒Ⅰ、Ⅱ、Ⅲ型(LQC株)的滴度均波动在±0.5 log10以内。其中RD细胞对LQC株均值及标准差为:Ⅰ型(8.26±0.19),Ⅱ型(7.78±0.20),Ⅲ型(8.15±0.20);L20B细胞对LQC株均值及标准差为:Ⅰ型(7.62±0.23),Ⅱ型(7.43±0.26),Ⅲ型(7.28±0.2)。结论 2013～2018年福建省脊灰实验室所用细胞系对脊灰病毒的敏感性良好,维持在预期参考值±0.5 log10以内,与预期参考值相比敏感性没有下降。

关键词： Sabin株脊髓灰质灭活疫苗(sIPV)   皮内免疫   免疫持久性   加强免疫   Wistar大鼠  

摘要： 脊髓灰质炎野毒株消灭后,口服脊髓灰质炎减毒活疫苗(Oral polio vaccine,OPV)将被停止使用,脊髓灰质炎灭活疫苗(Inactivated poliovirus vaccine,IPV)将全面替代OPV,但IPV成本过高,难以满足全球需要。皮内免疫可以降低Sabin株脊髓灰质炎灭活疫苗(Inactivated poliovirus vaccine derived from Sabin strain,sIPV)的免疫剂量,本研究将观察sIPV疫苗皮内免疫大鼠后的免疫持久性及加强免疫效果。本研究采用sIPV,设皮内免疫组、全剂量肌肉免疫组和皮内免疫阴性对照组,接种Wistar大鼠,于3剂基础免疫程序完成后第1个月、12个月采血;第12个月采血后加强免疫1剂,并于加强免疫1个月后采血。中和试验检测各血清抗脊灰病毒中和抗体效价,评价皮内免疫sIPV的免疫持久性及加强免疫效果。Wistar大鼠3剂基础免疫后1个月,1/5、1/3剂量皮内免疫组与全剂量肌肉免疫组Ⅰ、Ⅱ、Ⅲ型抗体阳转率均达到了100%,各型别中和抗体几何平均滴度(Geometric mean titer,GMT)均远高于1∶8保护水平。基础免疫后12个月,sIPV全剂量组各型阳转率均维持在80%以上,1/10剂量皮内免疫组在50%以上,1/5剂量皮内免疫组维持在70%以上,1/3剂量皮内免疫组维持在80%以上,除1/10剂量组Ⅱ型外其余各组各型别GMT均维持在1∶8以上。加强免疫后1个月,1/5剂量皮内免疫组、1/3剂量皮内免疫组及全剂量组的Ⅰ型、Ⅱ型、Ⅲ型各组中和抗体阳转率均达到100%,并能够诱导产生远高于1∶8的抗体水平。本研究结果显示sIPV疫苗皮内免疫具有良好的免疫持久性及加强免疫效果。

关键词： 脊髓灰质炎   脊髓灰质炎病毒   肠道病毒属   急性弛缓性麻痹  

摘要： 目的分析2013—2017年北京市报告的15岁以下儿童急性弛缓性麻痹(acute fluaccid paralysis,AFP)病例的肠道病毒监测情况。方法通过AFP监测信息报告管理系统,选取北京市2013-2017年报告的AFP监测病例的基本信息、疫苗免疫史、标本采集和检测情况、病例随访情况以及病例分类诊断结果等进行分析。采用x2检验或Fisher's精确概率检验不同特征的AFP病例间不同种类肠道病毒检出率的差异。结果2013-2017年,北京市共报告AFP病例960例,其中74例检出了肠道病毒,本地和异地的检出率分别为4.0%(7/176)和8.9%(67/756),差异有统计学意义(x2=4.66,P=0.031)。本地和异地病例的脊髓灰质炎(简称"脊灰")病毒检出率分别为3.4%(6/176)和3.0%(23/756)(x^2=3.48,P=0.062),检出的脊灰病毒均为脊灰疫苗株,病例麻痹前均口服过脊灰减毒活疫苗,分类诊断为脊灰野病毒排除病例,6例病例诊断为疫苗相关麻痹型脊髓灰质炎(vaccine associated paralytic poliomyelitis,VAPP)。本地和异地病例的非脊灰肠道病毒检出率分别为0.6%(1/176)和5.8%(44/756)(x^2=1.64,P=0.201),分类诊断结果均为脊灰野病毒排除病例。44例异地非脊髓灰质炎病毒检出者中79.6%的麻痹发生在5至9月。结论北京市报告本地AFP病例肠道病毒分离率低于异地AFP病例,根据脊灰病毒和非脊灰肠道病毒检出结果,AFP分类诊断均为脊灰野病毒排除病例,异地AFP病例中非脊髓灰质炎病毒呈现夏秋季流行。