Influenza B infections in children:A review

Influenza B(IFB)virus belongs to the Orthomyxoviridae family and has two antigenically and genetically distinct lineages;B/Victoria/2/87-like(Victoria lineage)and B/Yamagata/16/88-like(Yamagata lineage).The illness caused by IFB differs from that caused by influenza A.Outbreaks of IFB occur worldwide and young children exposed to IFB are likely to have a higher disease severity compared with adults.IFB mostly causes mild to moderate respiratory illness in healthy children.However,the involvement of other systems,a severe disease especially in children with chronic medical conditions and immunosuppression,and rarely mortality,has been reported.Treatment with oseltamivir or zanamivir decreases the severity of illness and hospitalization.Due to the enormous health and economic impact of IFB,these strains are included in vaccines.IFB illness is less studied in children although its impact is substantial.In this review,the epidemiology,clinical manifestations,treatment,prognosis,and prevention of IFB illness in children are discussed.

Screening of a High Growth Influenza B Virus Strain in Vero Cells

Due to the insufficient supply of embryonated chicken eggs,the preparation of large quantities of inactivated influenza vaccines will require an alternative virus culture system after the emergence or reemergence of a pandemic influenza virus.The Vero cell is one of the ideal options since it was used for producing many kinds of human vaccines.However,most of the influenza viruses can not grow well in Vero cells.To develop a new influenza vaccine with Vero cells as a substrate,the virus needs to adapt to this cell substrate to maintain high growth characteristics.By serial passages in Vero cells,the B/Yunnan/2/2005va(B)strain was successfully adapted to Vero cells,with the hemagglutination titer(HAT)of the virus reaching 1:512.The high growth characteristic of this strain is stable up to 21 passages.The strain was identified by hemagglutination inhibition (HAI)test and sequencing respectively;the HA1 gene sequence of the virus was cloned and analyzed.The screening and establishment of high growth B virus provides an important tool for influenza vaccine production in Vero cells.

冻干b型流感嗜血杆菌结合物疫苗中磷含量测定方法建立及验证

目的:建立冻干b型流感嗜血杆菌(Hib)结合疫苗磷含量检测的超滤法联合紫外分光光度法,并对该方法进行验证及初步应用。方法:用去离子水将样品溶解后超滤,收集超滤管中Hib多糖,采用等体积比硫酸高氯酸消解样品,使用钼酸铵在酸性条件下与磷形成磷钼酸,与维生素C生成蓝色化合物,在825 nm下有最大吸收。对该方法进行线性、精密度、稳定性、准确度验证。用建立的方法检测3批次商业化冻干Hib结合疫苗磷含量。结果:标准磷在质量浓度1~10μg·mL^(-1)内线性关系良好(r=1.000),线性方程为Y=8.878×10^(-2)X+2.402×10^(-3),方法在低、中、高浓度水平下回收率均值分别为在97.35%、96.65%、97.42%(n=3),RSD分别为2.55%、0.95%、0.95%;重现性试验的RSD为2.81%;中间精密度RSD 2.14%;磷标准品衍生物溶液室温放置1 h稳定,RSD为0.39%。结论:该方法结果准确、可靠,可用于冻干b型流感嗜血杆菌结合疫苗磷含量检测,同时也为其他多糖蛋白结合疫苗磷含量测定提供了思路。

神经介素B及受体NMBR和PD-L1在H9N2亚型流感病毒感染过程中的相互作用研究

神经介素B(NMB)及其G蛋白偶联受体(NMBR)发挥的抗甲型流感病毒免疫反应,以及甲型流感病毒感染诱导细胞程序性死亡配体1(PD-L1)高表达均与NF-κB信号通路有直接关系,而NF-κB信号通路的激活受ERK信号通路的调控。为深入探究NMB与NMBR调节H9N2亚型流感病毒感染诱导PD-L1上的作用,本研究以H9N2亚型流感病毒为模式毒株,基于NMBR干扰和过表达细胞系、PD-L1干扰和过表达细胞系以及C57BL/6小鼠,采用RT-PCR和Western blot方法分析NMB与NMBR对PD-L1表达变化以及ERK磷酸化的影响。结果显示:H9N2亚型流感病毒感染诱导的NMBR和PD-L1表达之间存在着负调控的关系,外源性NMB可以有效激活小鼠体内NMBR的表达,进而抑制PD-L1表达,NMB与NMBR也能影响H9N2感染诱导的ERK磷酸化水平。综上,H9N2亚型流感病毒感染诱导表达的NMB与NMBR通过ERK信号通路调节PD-L1的表达而发挥抗流感病毒作用,将为深度剖析宿主-甲型流感病毒之间的互作关系提供新的科学依据。

高效阴离子交换色谱-脉冲安培检测法测定吸附无细胞百(三组分)白破灭活脊髓灰质炎和b型流感嗜血杆菌(结合)联合疫苗的多糖含量

目的 采用高效阴离子交换色谱-脉冲安培检测法测定吸附无细胞百(三组分)白破灭活脊髓灰质炎和b型流感嗜血杆菌(结合)联合疫苗(以下简称DTac P-s IPV-Hib)中多糖含量,并对方法进行验证。方法 在1 ml样品中加入0.02 g柠檬酸钠,振荡混匀后,置于37℃保温24 h,4000×g离心5 min收集上清液,稀释后加入6 mol/L盐酸,100℃下加热2 h,冰浴10 min后加入0.8 ml氢氧化钠(1 mol/L)溶液用于终止酸水解。采用高效阴离子交换色谱-脉冲安培检测法根据检测信号峰面积计算对应水解荚膜多糖(PRP)含量,通过PRP占多糖含量干重的41.3%计算出总的多糖含量。结果 核糖醇参考品浓度在0.1~1.5μg/ml范围内标准曲线r2>0.99,检测下限可达10ng/ml。核糖醇加标回收率均在95%~105%;对高效阴离子交换色谱-脉冲安培检测法检测多糖的重复性和中间精密度进行验证,相对标准偏差(RSD)均小于5%,方法专属性和耐用性良好。结论 使用柠檬酸钠作为解吸附剂,与高效阴离子交换色谱-脉冲安培检测法相结合可用于DTac P-s IPV-Hib中Hib多糖的含量检测,为产品的质量控制和稳定性研究提供参考。

Using amino acid features to identify the pathogenicity of influenza B virus

Background:Influenza B virus can cause epidemics with high pathogenicity, so it poses a serious threat to public health. A feature representation algorithm is proposed in this paper to identify the pathogenicity phenotype of influenza B virus.Methods:The dataset included all 11 influenza virus proteins encoded in eight genome segments of 1724 strains. Two types of features were hierarchically used to build the prediction model. Amino acid features were directly delivered from 67 feature descriptors and input into the random forest classifier to output informative features about the class label and probabilistic prediction. The sequential forward search strategy was used to optimize the informative features. The final features for each strain had low dimensions and included knowledge from different perspectives, which were used to build the machine learning model for pathogenicity identification.Results:The 40 signature positions were achieved by entropy screening. Mutations at position 135 of the hemagglutinin protein had the highest entropy value (1.06). After the informative features were directly generated from the 67 random forest models, the dimensions for class and probabilistic features were optimized as 4 and 3, respectively. The optimal class features had a maximum accuracy of 94.2% and a maximum Matthews correlation coefficient of 88.4%, while the optimal probabilistic features had a maximum accuracy of 94.1% and a maximum Matthews correlation coefficient of 88.2%. The optimized features outperformed the original informative features and amino acid features from individual descriptors. The sequential forward search strategy had better performance than the classical ensemble method.Conclusions:The optimized informative features had the best performance and were used to build a predictive model so as to identify the phenotype of influenza B virus with high pathogenicity and provide early risk warning for disease control.

Superior mesenteric vein thrombosis induced by influenza infection:A case report

BACKGROUND Among the various types and causes of mesenteric ischemia,superior mesenteric vein(SMV)thrombosis is a rare and ambiguous disease.If a patient presents with SMV thrombosis,past medical history should be reviewed,and the patient should be screened for underlying disease.SMV thrombosis may also occur due to systemic infection.In this report,we describe a case of SMV thrombosis complicated by influenza B infection.CASE SUMMARY A 64-year-old male visited the hospital with general weakness,muscle aches,fever,and abdominal pain.The patient underwent computed tomography(CT)and was diagnosed with SMV thrombosis.Since the patient’s muscle pain and fever could not be explained by the SMV thrombosis,the clinician performed a test for influenza,which produced a positive result for influenza B.The patient had a thrombus in the SMV only,with no invasion of the portal or splenic veins,and was clinically stable.Anticoagulation treatment was prescribed without surgery or other procedures.The follow-up CT scan showed improvement,and the patient was subsequently discharged with continued oral anticoagulant treatment.CONCLUSION This case provides evidence that influenza may be a possible risk factor for SMV thrombosis.If unexplained abdominal pain is accompanied by an influenza infection,examination of an abdominal CT scan may be necessary to screen for possible SMV thrombosis.

感冒退热合剂联合重组人干扰素α1b治疗儿童乙型流感疗效

目的 观察感冒退热合剂联合雾化重组人干扰素α1b治疗儿童乙型流感的疗效。方法 选择2021年1月—2022年6月武汉市中医医院收治的80例乙型流感患儿作为研究对象,随机分为两组各40例。对照组予雾化重组人干扰素α1b治疗,研究组予感冒退热合剂联合雾化重组人干扰素α1b治疗。评价两组疗效、恢复情况[鼻咽拭子乙型流感病毒抗原(IBV-Ag)是否转阴,血清淀粉样蛋白A(SAA)、C反应蛋白(CRP)和体温是否恢复正常]和安全性,比较两组患儿治疗前后免疫指标(CD3^(+)、CD4^(+)、CD8^(+))、炎症因子[血清白细胞介素6(IL-6)、肿瘤坏死因子-α(TNF-α)、白细胞介素4(IL-4)、γ干扰素(IFN-γ)]水平变化。结果 治疗后研究组总有效率为90.00%,明显高于对照组的70.00%(P <0.05);研究组的IBV-Ag转阴比例,以及血清SAA、CRP和体温正常比例均显著高于对照组(P <0.05)。治疗后,两组患儿的CD3^(+)、CD4^(+)均较前明显升高(P <0.05),血清IL-6、TNF-α、IL-4、IFN-γ水平与CD8^(+)则均较前明显降低(P <0.01),且研究组上述指标均优于对照组(P <0.05)。两组不良反应总发生率差异无统计学意义(P> 0.05)。结论 感冒退热合剂联合雾化重组人干扰素α1b治疗儿童乙型流感效果良好,能促进患儿恢复,增强机体免疫,改善炎症因子水平,且安全性尚可。

A case of severe pneumonia caused by multiple bacterial organisms following type B influenza virus infection

A 50-year old woman, without any underlying disease, presented with pneumonia after experiencing flu-like symptoms. Streptococcus pneumoniae was identified on admission through blood culture and urine antigen tests. Staphylococcus aureus and Streptococcus pneumoniae were present in the sputum culture. Computed tomography showed cavity development in the consolidation areas, typical of staphylococcal pneumonia. The patient was intubated and received mechanical ventilation as respiratory failure progressed. She exhibited improvement following antibiotic therapy. The change in type B influenza virus serum titer confirmed that this was a unique case of severe pneumonia caused by multiple bacterial organisms following type B influenza virus infection.

The Correlation of IFN <i>γ</i>to the Preferential Isolation of Influenza Type B over Type A Viruses in Madin Darby Canine Kidney Cells

The isolation of influenza viruses in Madin Darby Canine Kidney (MDCK) cells has shown preferential isolation of a great percentage of Influenza B strains at the first passage than Influenza A strains. During in vitro isolation of Influenza viruses, majority of type A viruses are not confirmed as positive isolates by Hemagglutination (HA) assay despite having higher virulence and pathogenicity versus influenza B viruses. This study investigated the differences in IFN-γ and IL-10 cytokines secreted by MDCK cells upon exposure to the viruses and thus provided possible answers as to why influenza type B can easily be isolated from MDCK cells compared to influenza A. Positive influenza viruses were inoculated onto MDCK cells. IFN-γ and IL-10 cytokines stimulated by the viruses in MDCK cells were measured by indirect ELISA at 1 hour, 12 hours, 48 hours and 72 hours post inoculation (pi). A total of 46 specimens, with 23 specimens from each virus type were analyzed. IFN-γ was significantly higher at 1 hour pi in MDCK cells for influenza type A at p value of 0.024 than type B. No statistical significance was observed in means of cytokine IL-10 between influenza type A and type B. The study may show that IFN-γ is correlated to the preferential isolation of influenza type B over type A viruses. Anti-inflammatory cytokines may not necessarily be playing a role in the preferential growth of influenza type B, a less virulent type over influenza type A in MDCK cells.

Safety Observation Study on Haemophilus Influenza Type B Conjugate Vaccines Injected at Different Sites in Chinese Infants

In the present study, the safety of Hoemophilus influenza type b conjugate vaccines inoculated in the upper arm deltoid and vastus lateralis muscle was evaluated. 680 infants aged 2-5 months and 6-12 months were selected to be the research subjects in whom the Hib conjugate vaccines were inoculated by injection in the upper arm deltoid and vastus lateralis muscle, respectively. The safety analysis indicated that there were no statistic differences in the incidence rates of adverse reactions when the Hib conjugate vaccines were inoculated at different sites. So we concluded that the safety of inoculation injection of Hib conjugate vaccines in vastus lateralis muscle was the same as that inoculated in the upper arm deltoid.

H9N2亚型流感病毒感染过程中神经介素B及受体对NF-κB信号通路泛素酶的调控

神经介素B(neuromedin B,NMB)及受体(NMB receptor,NMBR)通过NF-κB信号通路参与抑制甲型流感病毒(influenza A virus,IAV)H1N1亚型(IAV/H1N1)的感染。但关于NMB和NMBR对NF-κB信号通路相关泛素蛋白酶的调控如何,尚未见报道。为探究NMB和NMBR调控IAV诱导的NF-κB信号通路相关的泛素蛋白酶表达的影响,本研究基于IAV/H9N2感染sh-NMBR细胞与NMB刺激的A549细胞,采用RT-PCR、qRT-PCR及Western blot(WB)分析NMB和NMBR对H9N2感染引起的NF-κB信号通路相关的E3泛素连接酶Mind bomb-2(MIB2)和Ring Finger Protein 8(RNF8)及去泛素蛋白酶Cylindromatosis(CYLD)的表达变化。结果显示:H9N2感染sh-NMBR细胞中,RNF8和CYLD表达增加,MIB2表达和P65磷酸化水平降低;NMB激活A549细胞中NMBR的表达后,诱导细胞中RNF8和CYLD的表达水平下降,MIB2表达和P65磷酸化水平增加。结果表明:NMB和NMBR通过调控IAV/H9N2感染诱导的泛素蛋白酶的表达和P65活性,从而影响IAV/H9N2感染激活的NF-κB信号通路的功能,该结果为深入研究NMB和NMBR抑制甲型流感病毒感染的作用机制提供了理论基础。

Invasive <i>Haemophilus influenzae</i>Type b (Hib) Infections in Children in the Pediatric Department of the University Hospital Gabriel Touré(UH-GT)

Introduction: According to Mali’s National Immunization Center, the Haemophilus influenzae b (Hib) vaccine coverage rate was 90% in 2015. Our work aimed to study invasive bacterial infections due to Haemophilus influenzae type b in children aged 0 - 15 years hospitalized in the pediatrics department of the UH-GT. Method: We carried out a retrospective descriptive study from January 2017 to December 2018 (i.e. 2 years) among children aged 0 - 15 years and hospitalized for Haemophilus influenzae type b infection confirmed by culture (blood culture, Cerebro-spinal Fluid, and pleural and skin fluid). Results: Thirty-three cases of Hib infections were collected giving a frequency of 0.2% and the age group 3 months to 3 years was the most affected (72.73%). Children who received no vaccine accounted for 21.21%. The Cerebro-spinal Fluid culture and other samples (pleural and skin) identified the bacterium in 100% of cases, against 72.72% in the blood culture Meningitis was the most frequent pathology (78.79%) and the lethality was high (21.21%). Conclusion: Despite the introduction of the Hib vaccine in the routine immunization program in Mali, Hib infections remain with a high lethality linked to meningitis.

评估三种不同品牌的新型冠状病毒抗原洗脱液对甲型/乙型流感病毒抗原检测盒的性能影响

目的:评估三种品牌新型冠状病毒抗原洗脱液对雅培(上海)诊断产品销售有限公司生产的Clearview甲型/乙型流感病毒抗原检测盒的性能影响,探讨研究使用一个样本同时进行新型冠状病毒抗原和甲型/乙型流感病毒抗原两种检测的可行性。方法:选取江苏大学附属医院就诊的102例患者,每人采取两根鼻拭子。按照各自的产品说明书对同一患者采集的双份鼻拭子分别用所选的三种品牌中的一种新型冠状病毒抗原洗脱液和甲型/乙型流感病毒抗原洗脱液进行抗原洗脱、同时检测甲型/乙型流感病毒抗原检测,对检测的结果进行符合率分析。结果:广州万孚生物技术股份有限公司的新型冠状病毒抗原洗脱液的检测Clearview甲型/乙型流感病毒抗原的结果,甲型流感病毒抗原阳性符合率为100%;乙型流感病毒抗原阳性符合率、阴性符合率、总符合率均为100%。杭州艾康生物技术有限公司的新型冠状病毒抗原洗脱液的检测Clearview甲型/乙型流感病毒抗原的结果,甲型流感病毒抗原阳性符合率、乙型流感病毒抗原阳性符合率均为100%;阴性符合率为90%;总符合率为97%。浙江东方基因生物制品有限公司的新型冠状病毒抗原洗脱液的检测Clearview甲型/乙型流感病毒的结果,甲型流感病毒抗原阳性符合率、乙型流感病毒抗原阳性符合率、阴性符合率、总符合率均为100%。结论:所试验的三种品牌的新型冠状病毒抗原洗脱液适用于雅培(上海)诊断产品销售有限公司生产的Clearview甲型/乙型流感病毒抗原检测。

贵州省2013—2016年B型流感病毒流行特征分析

目的了解贵州省B型流感病毒的流行特征和规律,为其预防与控制提供依据。方法采用描述性方法对贵州省2013年4月1日—2016年3月31日B型流感病毒RT-PCR检测结果进行统计。结果贵州省2013—2016年3个监测年度B型流感病毒RT-PCR检测阳性1 904份,其中By系1 215份、Bv系642份,2013年4月—2014年3月、2014年4月—2015年3月2个监测年度B型流感的优势流行株都是By系,而2015年4月—2016年3月是Bv和By系共同流行,流行季节主要在冬春季;B型流感病毒男性检出所占比率较高,占56.83%;15岁以下低年龄组人群B型流感病毒检出数最高(70.80%),而Bv系在0~岁年龄组最高(42.37%),By系在5~岁年龄组最高(35.56%);混合感染病原组合构成主要以By+Bv为主,占67.65%,与B型有关的混合感染数占95.59%。结论贵州省B型流感病毒存在By和Bv两种系别的流行,流行季节为冬春季,男性感染病例多于女性,发病以15岁以下人群为主,加强低年龄群体流感疫苗的接种和监测具有重要意义。

全球B型流感病毒耐药相关突变株NA和HA序列特征分析

目的研究全球B型流感耐药相关突变株的NA和HA序列特征及分子结构特点。方法对我国2008-2012年B型流感病毒进行序列测定和分析,确定耐药相关突变株,进一步利用MEGA5.0软件分析我国与全球其他国家B型流感病毒的耐药相关突变位点和伴随位点的异同,并构建系统进化树,利用RasWin软件在NA、HA蛋白分子模型中展示突变位点。结果我国2008-2012年共发现6株B型流感病毒耐药相关突变株,其携带的NA、HA伴随突变较少,且与国外B型耐药相关突变株的NA、HA序列处于不同的进化分枝上。结论目前发现的B型耐药相关突变株的突变位点多种多样,且我国的B型流感病毒耐药情况与国际情况并不十分一致,这提示加强我国乃至全球B型流感病毒耐药监测的重要性。

山东省2017—2018年B型流感病毒药物敏感性检测及神经氨酸酶基因特征分析

目的检测山东省2017-2018流感监测年度B型流感病毒对神经氨酸酶抑制剂的药物敏感性,分析其神经氨酸酶(NA)基因特征。方法选取山东省2017—2018年分离的18株B型流感病毒(Yamagata系16株,Victoria系2株),通过生物学耐药实验检测病毒对奥司他韦和扎那米韦的药物敏感性。提取病毒核酸后一步法RT-PCR扩增NA基因片段,双向测定核苷酸序列,对基因序列和氨基酸序列特征比对分析。结果在检测的18株B型流感病毒中,有1株Yamagata系病毒对奥司他韦和扎那米韦2种药物的敏感性均降低,此株病毒的NA基因发生H274Y位点突变。其余15株Yamagata系病毒和2株Victoria系病毒均为奥司他韦及扎那米韦的敏感株。结论随机选取的18株B型流感病毒中大多数病毒对神经氨酸酶抑制剂敏感,临床上可继续使用此类药物对流感患者进行治疗。应加强耐药性监测,警惕耐药株的出现。

B型流感病毒核衣壳蛋白ELISA捕获法的建立和临床应用

目的制备和鉴定B型流感病毒核衣壳(N)蛋白单克隆抗体(mAb),建立双抗体夹心捕获抗原ELISA,用于B型流感病毒感染的早期诊断。方法用重组B型流感病毒N蛋白和B型流感病毒抗原免疫BALB/c小鼠制备mAb,采用ELISA间接法、免疫荧光(IFA)和免疫印迹(WB)进行筛选和鉴定,通过竞争抑制试验分析抗体识别表位,并采用抗体配对试验建立双抗体夹心捕获抗原ELISA检测B型流感病毒N抗原。结果获得12株特异性针对B型流感病毒N蛋白的mAb,识别8个不同的抗原位点,根据mAb识别抗原表位,对mAb进行多种组合的配对试验,筛选出2株单抗BN4和BN8混合作为捕获抗体,辣根过氧化物酶标记的单抗BN1和BN5混合作为测定抗体,建立了双抗体夹心ELISA,测定新鲜的漱口液标本的灵敏度达100%,而对冻融的漱口液标本检测灵敏度为83.9%,与其他呼吸道病毒如A型流感病毒、副流感病毒等无交叉反应,特异度达100%。结论获得特异性好的mAb,经过抗体的配对和优化,建立了一种灵敏度高、特异性强的B型流感病毒抗原的ELISA捕捉法,可用于B型流感病毒感染的早期实验室诊断及流行病学研究。

两株B型流感病毒的基因组序列分析

目的了解两株B型流感病毒的基因组序列特征。方法对两株B型流感病毒进行全基因组序列测定和基因进化特性的分析。结果成功扩增出两株B型流感病毒的全基因组序列,并且两毒株的基因组均属于Yamagata系类似株Ⅱ系。两株病毒的基因组序列与疫苗株B/Florida/4/2006(Yamagata系)以及Victoria系代表株B/Brisbane/60/2008、B/Malay-sia/2506/2004相比,HA基因同源性为89.7%～97.3%,NB基因同源性则为95.4%～98.4%。两株病毒的HA蛋白与WHO推荐的疫苗株B/Florida/4/2006(Yamagata系)相比,存在11处氨基酸突变,其中HA的N131K氨基酸位点突变,可能对抗原性产生影响。NB的S198N氨基酸位点突变可能影响神经氨酸酶抑制剂的灵敏度。结论两株B型流感病毒的遗传进化状态稳定,但是与同分支中的毒株基因序列部分位点存在差异。

多重RT-PCR同步快速检测A型和B型流感病毒

目的 建立特异、敏感、快速、同步检测含漱液中A、B型流感病毒的分子生物学检测方法。 方法 以流感病毒A型保守的M基因和流感病毒B型的NS基因为模板分别设计的两对引物 ,用MRT -PCR同时扩增A型M基因和B型NS基因的片断 ,得到相对应的病毒片段 ,根据扩增出的片段的位置和大小来判断含漱液中A、B型流感病毒分型。 结果 用MRT -PCR从 19株A型流感病毒毒株和 11株B型流感病毒毒株分别特异地扩增出M基因 5 0 1bp的片段和NS基因 13 6bp的片段 ,灵敏度可达 1 6× 10 -5TCID5 0 ;对 2份黑天鹅的咽拭子和肺组织标本均检出A型流感病毒M基因 5 0 1bp的片段。 结论 多重逆转录聚合酶链反应能特异、敏感快速的检测A、B型流感病毒。