Influenza A in Young Children with Suspected Respiratory Syncytial Virus Infection

OBJECTIVES: To determine the prevalence of influenza A in young children suspected of having respiratory syncytial virus (RSV) infection and to compare the clinical presentation of these patients with those who have proven RSV infection. METHODS: Children younger than or at 36 months of age who presented to a pediatric emergency department (ED) with suspected RSV infection during the influenza A season of 2001-2002 were eligible. Eligible children had an RSV antigen test ordered as part of their initial clinical management. A consecutive sample of children was enrolled for prospective observational analysis. The main outcome measure was the prevalence of influenza A in young children with suspected RSV infection. The secondary outcome measure was a comparison of the clinical presentations, of the two groups. RESULTS: During the study period, 420 patients presented for evaluation of respiratory illness. RSV tests were ordered on 251 patients. Of 197 eligible patients, 124 (63%) tested positive for RSV and 33 (17%) for influenza A. Influenza A patients were more likely to have temperatures at or above 39 degrees C than RSV patients (36% vs. 15%; p = 0.01). RSV patients were more tachypneic (54 vs. 43 breaths/minute; p < 0.0001) and more often had wheezing (90% vs. 8%; p < 0.0001). Twenty influenza patients (61%) were hospitalized. CONCLUSIONS: This study found a high prevalence of influenza A in young children suspected of having RSV infection. Clinicians should consider influenza A in young febrile children presenting with respiratory illnesses.     

急性下呼吸道合胞病毒感染190例的淋巴细胞亚群分析

目的分析急性下呼吸道合胞病毒感染患儿的外周血淋巴细胞亚群的变化,为临床免疫调节治疗提供依据。方法对小于6个月急性下呼吸道感染住院患儿行痰病原学检测,明确为呼吸道合胞病毒为感染组。选择门诊体检儿童为对照组。同时两组病例抽外周血采用流式细胞仪检测淋巴细胞亚群值。结果感染组CD3＋、CD3＋CD8＋低于对照组,差异有统计学意义（P〈0．05）;CD3．CD19＋、CD19＋CD23＋、CD4＋／CD8＋、CD3＋CD25＋高于对照组,差异有统计学意义（P〈O．05）。感染组与对照组CD3＋CD4＋、CD16＋CD56＋差异无统计学意义（P〉0．05）。结论急性下呼吸道合胞病毒感染患儿的细胞免疫功能紊乱：T淋巴细胞受到全面抑制,B淋巴细胞激活参与病毒的清除,NK细胞比例变化不显著。     

清肺解毒法治疗小儿呼吸道合胞病毒肺炎的临床分析

目的探讨清热解毒法治疗小儿呼吸道合胞病毒肺炎的临床疗效。方法选择2014年5月~2016年5月我院收治的74例小儿呼吸道合胞病毒肺炎患儿作为此次研究对象,把全部患儿依据不同治疗方法分为对照组与治疗组,每组37例,对照组采用常规西药治疗,治疗组采用清肺解毒法治疗,比较两组患儿临床疗效。结果治疗组患儿的退热时间、痰壅消失时间、止咳时间以及肺部湿罗音消失时间要显著小于对照组(P0.05);治疗组临床总有效率是97.30%,对照组临床总有效率是72.97%,治疗组患儿临床治疗效果要显著优于对照组(P0.05)。结论小儿呼吸道合胞病毒肺炎应用清肺解毒法治疗具有显著临床疗效,可以明显改善患儿临床症状恢复状况,值得在临床上大力推广应用。     

苏州地区儿童呼吸道合胞病毒感染的流行病学研究

目的 调查苏州地区儿童呼吸道合胞病毒（RSV）感染的流行现状及其影响因素,为RSV感染的防治提供依据.方法 收集苏州大学附属儿童医院2008年5月～2011 年4月三年间因呼吸道感染住院的患儿痰标本18,170例,采用直接免疫荧光法检测RSV抗原.结果 18,170例呼吸道感染患儿中,RSV阳性者2,773例,阳性检出率15.26%,82.87%的RSV感染发生在12月以下患儿;男女比例1.97：1（P＜0.001）,发病高峰集中在每年的12月至次年的3月;12月以内母乳喂养儿较非母乳喂养儿RSV阳性检出率低,年龄小于6月或在流行季节出生、被动吸烟、母亲吸烟、兄妹数量等均可增加RSV的感染率.结论 苏州地区儿童RSV感染的流行状况与国内和国外温带城市情况基本一致,冬春季为流行高峰,0～12月龄组的患儿RSV感染所占比例最大.母乳喂养具有保护作用,男性、被动吸烟、母亲吸烟、多兄弟姐妹、年龄小于6月或在流行季节出生等因素均增加患儿RSV感染风险.     

Clinical Decision Support and Palivizumab: A Means to Protect from Respiratory Syncytial Virus

Background and Objectives

Palivizumab can reduce hospitalizations due to respiratory syncytial virus (RSV), but many eligible infants fail to receive the full 5-dose series. The efficacy of clinical decision support (CDS) in fostering palivizumab receipt has not been studied. We sought a comprehensive solution for identifying eligible patients and addressing barriers to palivizumab administration.

Methods

We developed workflow and CDS tools targeting patient identification and palivizumab administration. We randomized 10 practices to receive palivizumab-focused CDS and 10 to receive comprehensive CDS for premature infants in a 3-year longitudinal cluster-randomized trial with 2 baseline and 1 intervention RSV seasons.

Results

There were 356 children eligible to receive palivizumab, with 194 in the palivizumab-focused group and 162 in the comprehensive CDS group. The proportion of doses administered to children in the palivizumab-focused intervention group increased from 68.4% and 65.5% in the two baseline seasons to 84.7% in the intervention season. In the comprehensive intervention group, proportions of doses administered declined during the baseline seasons (from 71.9% to 62.4%) with partial recovery to 67.9% during the intervention season. The palivizumab-focused group improved by 19.2 percentage points in the intervention season compared to the prior baseline season (p < 0.001), while the comprehensive intervention group only improved 5.5 percentage points (p = 0.288). The difference in change between study groups was significant (p = 0.05).

Conclusions

Workflow and CDS tools integrated in an EHR may increase the administration of palivizumab. The support focused on palivizumab, rather than comprehensive intervention, was more effective at improving palivizumab administration.     

Influenza: A Clinical Update Following a Century of Influenza Science

Although influenza science has come a long way since the 1918 Spanish flu pandemic, influenza continues to be a leading cause of morbidity and mortality. This review provides current, evidence-based recommendations regarding influenza prevention, diagnosis, and treatment. Nurse practitioners can help reduce influenza-associated morbidity and mortality by receiving annual influenza vaccinations, encouraging patients and community members to receive annual influenza vaccinations, developing and implementing strategies to improve influenza vaccination rates, encouraging preventive personal and community nonpharmaceutical interventions during influenza outbreaks, and by routinely reviewing and implementing current influenza recommendations from the Centers for Disease Control and Prevention.     

An outbreak of respiratory tract infection due to Respiratory Syncytial Virus-B in a postpartum center

Background

An outbreak of respiratory tract infection due to Respiratory Syncytial Virus (RSV) type B in a postpartum center was reported on February 1, 2017. Investigation was conducted to identify the magnitude, possible source of infection and risk factors for this outbreak on February 2, 2017.

Development of a Rapid Automated Influenza A,Influenza B,and Respiratory Syncytial Virus A/B Multiplex Real-Time RT-PCR Assay and Its Use during the 2009 H1N1 Swine-Origin Influenza Virus Epidemic in Milwaukee,Wisconsin

Rapid, semiautomated, and fully automated multiplex real-time RT-PCR assays were developed and validated for the detection of influenza (Flu) A, Flu B, and respiratory syncytial virus (RSV) from nasopharyngeal specimens. The assays can detect human H1N1, H3N2, and swine-origin (S-OIV) H1N1 Flu A viruses and were effectively used to distinguish Flu A infections (of all subtypes) from Flu B and RSV infections during the current S-OIV outbreak in Milwaukee, WI. The analytical limits of detection were 10⁻² to 10¹ TCID₅₀/ml depending on the platform and analyte and showed only one minor cross-reaction among 23 common respiratory pathogens (intermittent cross-reaction to adenovirus at >10⁷ TCID₅₀/ml). A total of 100 clinical samples were tested by tissue culture, both automated assays, and the US Food and Drug Administration-approved ProFlu+ assay. Both the semiautomated and fully automated assays exhibited greater overall (Flu A, Flu B, and RSV combined) clinical sensitivities (93 and 96%, respectively) and individual Flu A sensitivities (100%) than the Food and Drug Administration-approved test (89% overall sensitivity and 93% Flu A sensitivity). All assays were 99% specific. During the S-OIV outbreak in Milwaukee, WI, the fully automated assay was used to test 1232 samples in 2 weeks. Flu A was detected in 134 clinical samples (126 H1N1 S-OIV, 5 H1N1 [human], and 1 untyped) with 100% positive agreement compared with other “in-house” validated molecular assays, with only 2 false-positive results. Such accurate testing using automated high-throughput molecule systems should allow clinicians and public health officials to react quickly and effectively during viral outbreaks.Tissue culture had been the gold standard for respiratory virus diagnosis until approximately the mid-1990s when large multiplex RT-PCR assays first became available clinically and commercially.^{1,2,3,4,5,6,7} RT-PCR was quickly shown to be significantly more sensitive and highly specific for the detection of influenza (Flu) and respiratory syncytial viruses (RSV) (and most other respiratory viruses as well). Since that time, many laboratories (including the Midwest Respiratory Virus Program) have worked to develop automated platforms that would encompass nucleic acid extraction, RT-PCR amplification, and detection ^8,9,10,11. The goals have been to decrease technician time to only a few minutes, to make the assay time only 2 to 3 hours (or faster), to decrease cost, and to keep the footprint of the equipment as small as possible. In early 2008, two multiplex RT-PCR assays received US Food and Drug Administration (FDA) clearance for the detection of Flu A, Flu B, and RSV A/B. xTAG RVP (Luminex Molecular Diagnostics, Toronto, ON, Canada) is capable of detecting 9 viruses and a combined 11 subtypes for 3 of these viruses.¹² This is an open format assay, which increases the chance for contamination, and requires approximately 8 hours for completion and the use of a Luminex flow cytometer. The second FDA-approved multiplex RT-PCR assay is the ProFlu+ Assay (Prodesse, Waukesha, WI), which is capable of detecting Flu A, Flu B, and RSV simultaneously. The assay takes approximately 3 hours, excluding extraction time, and as approved, is semiautomated: using automated extraction via the NucliSENS easyMAG System (bioMérieux, Durham, NC) or the MagNA Pure LC Instrument (Roche, Indianapolis, IN) followed by manual transfer for real-time thermocycling on a Smart Cycler II (Cepheid, Sunnyvale, CA). In addition to these multiplex tests, the FDA, in September 2008, approved a series of singleplex RT-PCR assays developed by the Centers for Disease Control and Prevention that are capable of typing Flu viruses as A or B and further subtyping Flu A viruses as H1, H3, or H5 subtypes. However, the reagents are only readily available to members of the Centers for Disease Control and Prevention''s Laboratory Response Network.¹³The dearth of FDA-approved Flu A, Flu B, and RSV assays has led a number of laboratories to develop their own “in-house” singleplex or multiplex semiautomated assays using commercial automated extractors, real-time thermocyclers, and research use-only reagents. Our laboratory has recently developed semiautomated and fully automated multiplex RT-PCR assays capable of detecting Flu A, Flu B, and RSV A/B with a noncompetitive RNA internal control (MS2 RNA phage, ZeptoMetrix Corp., Buffalo, NY). The semiautomated assay uses the NucliSENS easyMAG System for automated nucleic acid extraction and a rapid microfluidics-based real-time thermocycler (Raider, HandyLab Inc., Ann Arbor, MI) for amplification and detection. The fully automated assay is run on the Jaguar (HandyLab, Inc.), which performs automated extraction followed by amplification and detection on a similar microfluidics-based real-time thermocycler. These platforms were chosen because they have an open format, which allows laboratories to run their own assays while maintaining high throughput with minimal hands-on technician time.The assays were designed with Pleiades probes, which use modified bases for selecting specific melt temperatures and a minor groove binder (Epoch Biosciences, Inc., Bothell, WA).¹⁴ Although this chemistry is similar to that of previously described Epoch analyte specific reagents,¹⁵ those reagents required modification to perform optimally on the easyMAG/Raider platform. After optimization in the semiautomated system, the assay was adapted to the completely automated Jaguar system. On completion of analytical development, both assays were compared with tissue culture, an in-house RT-PCR-enzyme hybridization assay, and the FDA-approved ProFlu+ assay to determine specificity and sensitivity before routine use in our clinical laboratory.Beginning in March 2009, infections caused by a novel influenza virus [H1N1 swine origin influenza virus (S-OIV)] began to be recognized around the world.^16,17 On April 28, 2009, our laboratory detected and confirmed (April 29) the first patient with the novel Flu A S-OIV in the state of Wisconsin. The lack of knowledge concerning this new strain as well as public and medical concern over an apparently unprotected population led to many public health decisions that increased the number of patients and physicians seeking specific viral diagnostic information in a rapid time frame. We describe the use of this rapid, fully automated Flu A, Flu B, and RSV assay/system in testing large numbers of patient specimens over a very short time period during the ongoing S-OIV outbreak. This outbreak demonstrates the importance of having rapid, reliable, sensitive, and specific assays that allow clinicians and public health officials to react quickly and effectively during viral outbreaks.     

外周血NLR，PLR和LMR水平分析在儿童流感病毒与疱疹性咽峡炎感染鉴别诊断中的临床意义

目的　探讨外周血全血细胞分析中的三项指标在鉴别儿童流感病毒和疱疹性咽峡炎的临床意义。方法　收集2019年11月1日 ～2020年1月31日商洛市中心医院就诊的有上呼吸道感染症状患儿189例,采用胶体金法检测甲乙流感病毒抗原,采集患儿初诊时外周血进行全血细胞分析。研究组纳入甲型流感85例,乙型流感43例。对照组纳入甲乙流感病毒阴性的疱疹性咽峡炎患儿61例。分别比较三组之间中性粒细胞和淋巴细胞计数比值（NLR）、血小板和淋巴细胞计数比值（PLR）、淋巴细胞和单核细胞计数比值（LMR）水平,并对结果进行统计学分析。结果　流感组与对照组的三项感染指标水平比较,差异均有统计学意义（F=11.51,13.00和29.37,均P<0.05）。进一步对甲流组和乙流组进行比较,两组之间的NLR,PLR和LMR水平差异有统计学意义（均P<0.05）。三项感染指标的ROC曲线下面积 (area under the curve,AUC)分别为0.723,0.837和0.725,当NLR截点为3.77时,灵敏度和特异度分别为60%和73%;PLR截点为147.83时,灵敏度和特异度分别为71.1%和80% ;LMR截点为2.57时,灵敏度和特异度分别为71.8%和65%。结论　在甲乙型流感病毒感染与疱疹性咽峡炎的辅助鉴别诊断中PLR优于NLR和LMR两项指标。     

甲型流感病毒肺炎的影像学特征分析

[目的]探讨甲型流感病毒肺炎的高分辨率CT 影像特征.[方法]回顾性分析临床诊断甲型流感病毒肺炎患者10例CT图像,分析CT表现形态（实变、磨玻璃影、结节、网格状改变）、病变分布、淋巴结肿大、胸腔积液、病变转归等.[结果]10例患者均为双侧肺部受累,其中周围型8例（80%）、周围＋中央型2例（20%）;双侧对称性分布7例（70%）,双侧不对称分布3例（30%）;磨玻璃影10例（100%）,同时合并实变影5例（50%）,合并网格状改变3例（30%）,4 例（40%）病人出现胸腔积液;本组病例均未见明显肿大的淋巴结;10例患者经治疗8例（80%）病变范围缩小,2例（20%）病变范围进展.[结论]与既往流感相关的病毒性肺炎对比,本组甲型流感病毒肺炎起病急、病程进展迅速和严重,首发CT表现以双肺弥漫分布的磨玻璃影为主,恢复过程中出现了不同程度的纤维化,对抗病毒药物和糖皮质激素治疗有较好反应.     

呼吸道合胞病毒感染患儿外周血NDR1和miR-146a表达水平及其临床意义

目　的　探讨丝苏氨酸蛋白激酶 1(Nuclear Dbf2 p-related kinase 1, NDR1)和微小核糖核酸（micro RNA, miR）146a在呼吸道合胞病毒（ Respiratory syncytial virus,RSV）感染患儿外周血清中的表达情况及临床意义。方法　收集 2019年 7月～ 2020年 5月西北大学附属医院（西安市第三医院）检验科、西安市儿童医院就诊的 77例 RSV感染患儿作为研究对象。按照病情严重程度分为重症组 36例,轻症组 41例。同时选取 53例同期来医院体检的健康儿童为对照组。采用实时荧光定量 PCR（qRT-PCR）法检测外周血清中 miR-146a表达水平;酶联免疫吸附法（ ELISA）检测 NDR1水平;Pearson法分析 NDR1与 miR-146a表达的相关性及二者与相关炎性因子表达的相关性。受试者工作特征曲线（ ROC）评估血清 NDR1和 miR-146a水平对 RSV感染严重程度的诊断价值。结果　与对照组相比, RSV感染患儿外周血中 NDR1水平（ 9.95±2.38 pg/L vs 6.46±1.12 pg/L）下调, miR-146a表达水平（ 1.03±0.17 vs 2.12±0.43）上调,差异具有统计学意义（ tmiR-146a=17.519,tNDR1=11.204,均 P＜ 0.05）。RSV感染重症组、轻症组及对照组中 hs-CRP,IL-4, IL-5,IL-6,IL-2和 IFN-γ比较差异均有统计学意义（ F=67.825,564.775,256.06,202.992,77.579,320.470,均 P＜ 0.05）。 RSV感染患儿血清 NDR1水平与 IL-2,IFN-γ表达均呈正相关（ r=0.473,0.620,均 P＜ 0.05）,与 hs-CRP,IL-4, IL-5,IL-6水平呈负相关（ r=-0.259,-0.559,-0.422,-0.505,均 P＜ 0.05）; miR-146a与 hs-CRP,IL-4,IL-5,IL-6水平均呈正相关（ r=0.381,0.636,0.421,0.570,均 P＜ 0.05）,与 IL-2,IFN-γ水平呈负相关（ r=-0.646,-0.744,均 P＜ 0.05）;RSV感染患儿外周血清中 NDR1与 miR-146a表达水平呈负相关（ r=-0.225,P＜ 0.05）;ROC结果显示,血清 NDR1,miR-146a水平预测重症 RSV感染患儿的曲线下面积（ AUC）分别为 0.911（95%CI:0.823～ 0.964）, 0.741（95%CI:0.628～ 0.834）,敏感度分别为 82.93%,68.29%,特异度分别为 88.89%,75.00%,二者联合预测重症 RSV感染患儿的 AUC为 0.925（95%CI:0.842～ 0.973）,敏感度和特异度分别为 90.24%和 83.33%。结论　NDR1在 RSV感染患儿外周血清中呈低表达,miR-146a呈高表达,二者可作为评估患儿病情发展的潜在指标。     

儿童甲、乙型流感病毒感染外周血中性粒细胞 /淋巴细胞比值的临床意义

目的　探讨外周血全血细胞分析中的四项指标在儿童甲、乙型流感病毒感染中的临床意义。方法　回顾性分 析2018 年1 月~2019 年1 月在北京儿童医院就诊的发热和/ 或急性呼吸道症状的门诊患儿468 例。采用间接免疫荧光 法检测血清甲、乙型流感病毒IgM 抗体,采用流式细胞计数法进行外周血全血细胞分析。每组按年龄分为＜ 4 岁组和 ≥ 4 岁组。研究组纳入甲型流感患儿138 例,乙型流感患儿177 例,对照组纳入有呼吸道感染症状但甲、乙型流感病毒 阴性的患儿153 例。分别比较三组白细胞(white blood cell,WBC)、中性粒细胞(neutrophil,NEU)、淋巴细胞(lymphocyte, LYM)和中性粒细胞/ 淋巴细胞比值 (neutrophil-to-lymphocyte ratio,NLR)的水平,并对结果进行统计学分析。结果　在＜ 4 岁组和≥ 4 岁组中,四项指标与对照组相比差异有统计学意义( ＜ 4 岁组χ2=48.721~159.45,≥ 4 岁组χ2=36.79~93.56, 均P ＜ 0.001)。＜ 4 岁组,四项指标的受试者特征曲线(receiver operator characteristic curve,ROC) 的曲线下面积(area under the curve,AUC) 分别为0.765,0.904,0.742 和0.924,当NLR 取临界值1.12 时,敏感度为87.8%,特异度为 86.3%。≥ 4 岁组,四项指标的ROC-AUC 分别为0.823,0.937,0.799 和0.977,当NLR 取临界值1.65 时,敏感度为 94.1%,特异度为94.8%。进一步对甲、乙流感组进行比较,＜ 4 岁组中,两组之间WBC,NEU 和NLR 差异有统计学 意义(P ＜ 0.001)。结论　NLR 优于其他三项常规感染指标,有望作为诊断儿童甲、乙流感病毒感染的潜在指标。     

儿童呼吸道合胞病毒感染血清特异性抗体IgM,IgG和IgA表达的相关性研究

目的 探讨住院儿童呼吸道合胞病毒(RSV)感染血清特异性抗体IgM,IgG和IgA表达的相关性,筛选具有早期辅助诊断意义的抗体指标。方法 运用荧光定量聚合酶链反应技术(FQ-PCR)筛选出2015～2017年50例咽拭子RSV阳性的住院患儿; 采用酶联免疫吸附试验(ELISA)检测患儿血清中的特异性抗体IgM,IgG和IgA; 同时以95例无呼吸道感染症状的儿童血清标本作为对照组; 采用卡方检验对结果进行统计学分析。结果 50例咽拭子RSV阳性患儿血清中IgM,IgG,IgA及三者同时出现阳性率分别为24.00%,60.00%,22.00%%和16.00%,差异有统计学意义(χ2=28.19,P<0.01); 同一性别患儿的IgM,IgG和IgA阳性率在实验组和对照组中差异有统计学意义(χ2=9.16,P<0.01),不同性别在同一实验组或对照组中各抗体阳性率差异无统计学意义(χ2=0.10,P>0.05); 急性喉气管支气管炎中未检出IgM,IgG和IgA,仅在急性上呼吸道感染中检测到1例IgG,支气管肺炎及急性支气管炎中以IgG的检出率41.38%和23.53%最高,且均未单独检测到IgA; <6个月年龄组患儿在7天和21天内均未检出IgM和IgA,1～5岁年龄组患儿在7天内产生IgM阳性率为50.00%最高,且在21天内均能检出IgM,IgG和IgA,5～10岁年龄组患儿在7天内产生IgG和IgA的阳性率为100%和66.67%。结论 RSV特异性抗体IgM,IgG和IgA不能单独作为早期感染RSV的诊断指标,特异性抗体产生不受性别因素影响,上呼吸道感染RSV较难产生IgM,IgG和IgA,患儿年龄越小产生IgM和IgA的速度越慢,同时IgG存在母婴垂直传播且对机体无保护作用,RSV感染人体引起临床呼吸道症状可能与自身免疫力有关; IgA产生最早且不单独出现。     

中国内地首例输入性甲型H1N1流感诊治经过及文献复习

目的：探讨甲型H1N1流感的诊治。方法：对中国内地首例输入性新甲型H1N1流感病例诊治经过临床分析并文献复习。结果：通过流行病学史、临床表现、甲型H1N1流感病毒的核酸检测（real-time RT-PCR法）可明确诊断。经中西医积极治疗痊愈出院。结论：2009年中国内地首例输入性甲型H1N1流感病例临床表现较轻,病程短,无并发症;推测此次致病的甲型H1N1流感毒力小,病毒清除迅速,预后良好。     

A Multi-Targeting,Nucleoside-Modified mRNA Influenza Virus Vaccine Provides Broad Protection in Mice

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