Severe acute respiratory syndrome (SARS) in children: epidemiology, presentation and management

Severe acute respiratory syndrome (SARS) is a newly recognised and highly contagious respiratory infection caused by a new strain of coronavirus. The disease can result in progressive respiratory failure in adults and the mortality rate has been reported to be 8-15%. This infection spreads by droplet transmission and children appear to acquire SARS through close household contact exposure to infected adults. Disease severity is, however, much milder in the paediatric age group. The common laboratory findings in infected children and adolescents include lymphopaenia and elevated levels of lactate dehydrogenase and creatinine phosphokinase. Air space consolidation is commonly seen during the course of the illness although chest radiographs are normal on presentation in half of the cases. The pathophysiology of SARS appears to be related to immunological dysregulation in response to the coronavirus infection. The optimal treatment of SARS in children remains to be determined. No case fatality in infected children has been reported. The early and proper isolation of infected adults, meticulous infection control measures in the hospital setting, exhaustive contact tracing and quarantine measures are important steps in preventing the spread of the disease among health care workers and into the community. The development of a sensitive and rapid test for early diagnosis is underway. Further controlled trials are necessary to define the optimal treatment of this infection in children.     

Childhood severe acute respiratory syndrome, coronavirus infections and asthma

Severe acute respiratory syndrome (SARS) is a new infectious disease caused by a novel coronavirus. Children appear to be less susceptible to the SARS coronavirus, although the other non-SARS coronaviruses can cause respiratory infections in adults and in children of all ages. The exact reasons as to why SARS preferentially affects adults, and not children, are still unknown. Many hypotheses exist and need to be explored. During the outbreak of SARS, there did not appear to be an increase in asthma exacerbations in children.     

Epidemiology of severe acute respiratory syndrome (SARS): adults and children

Severe acute respiratory syndrome (SARS) is a newly described respiratory infection with pandemic potential. The causative agent is a new strain of coronavirus most likely originating from wild animals. This disease first emerged in November 2002 in Guangdong Province, China. Early in the outbreak the infection had been transmitted primarily via household contacts and healthcare settings. In late February 2003 the infection was transmitted to Hong Kong when an infected doctor from the mainland visited there. During his stay in Hong Kong at least 17 guests and visitors were infected at the hotel at which he stayed. By modern day air travel, the infection was rapidly spread to other countries including Vietnam, Singapore and Canada by these infected guests. With the implementation of effective control strategies including early isolation of suspected cases, strict infection control measures in the hospital setting, meticulous contact tracing and quarantine, the outbreak was finally brought under control by July 2003. In addition, there were another two events of SARS in China between the end of December 2003 and January 2004 and from March to May 2004; both were readily controlled without significant patient spread.     

长沙地区急性下呼吸道感染住院儿童人博卡病毒感染的初步研究

目的 了解人博卡病毒(HBoV)在长沙地区急性下呼吸道感染住院儿童中的流行情况及临床特征,比较分析其区域流行特点.方法 收集2007年9月 - 2008年3月长沙地区773份急性下呼吸道感染住院儿童鼻咽抽吸物(nasopharyngeal aspirates,NPAs)样本进行HBoV病毒NP1基因检测,将PCR阳性产物测序,并将所测序列在GenBank中进行比较分析.结果 773例样本中,HBoV阳性例数87例,HBoV感染患儿年龄为18 d ～ 64个月,冬春季节流行,主要的临床诊断与症状是支气管肺炎与咳嗽;所测序列与GenBank公布的不同地区的HBoV NP1基因核苷酸序列同源性达99.53%,氨基酸序列同源性达99.8%,对核苷酸序列作基因进化树分析显示属于1种基因型.结论 长沙地区部分急性下呼吸道感染儿童与人博卡病毒有关,且HBoV 感染在低年龄组的儿童中更常见;一种基因型在长沙地区流行.     

亚细亚酸对兔未成熟肺缺血再灌注损伤的保护作用

目的 观察亚细亚酸对兔未成熟肺缺血再灌注损伤的保护作用。方法 选用15~21日龄新西兰白兔60只,分为5组：假手术组,对照组,亚细亚酸低、中和高剂量组,每组各12只。建立单肺缺血再灌注模型,肺门阻断1 h后,开放再灌注4 h。亚细亚酸低、中和高剂量组分别于术前3 d给予亚细亚酸7.5、15和30 mg·kg-1,假手术组仅开胸不阻断肺门,对照组不予干预。术毕收集肺组织,光镜和电镜观察肺组织病理和超微结构改变。测定肺组织丙二醛（MDA）,细胞毒性活性氧（ROS）-HR、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-PX）水平。Western Blot检测髓样生化因子（MyD）88和核转录因子（NF-κB）水平。ELISA法检测IL-1β、TNF-α水平。结果 ①亚细亚酸中和高剂量组肺缺血再灌注损伤明显减轻,光镜下肺泡与肺泡间隔肿胀程度明显轻于对照组,肺泡腔渗液减少,出血少见。电镜下可见肺泡上皮与血管内皮细胞脱落明显减少。②亚细亚酸中和高剂量组较对照组肺组织MDA,ROS-HR水平明显降低,SOD及GSH-PX水平明显升高;各时点的IL-1β、TNF-α水平也有不同程度下降,特别是再灌注后的2 h和4 h(P<0.05);肺组织中MyD88和NF-κB表达显著下降。③亚细亚酸中和高剂量的保护效果较好。结论 亚细亚酸对未成熟肺缺血再灌注损伤有一定的保护作用,其机制与清除氧自由基和减轻全身炎性反应有关。     

人冠状病毒与人类呼吸道感染

21世纪初10余年,新型及变异人类呼吸道病毒已多次威胁全球人类。2012年9月2513,WHO发布3天前在英国确诊的1例新型冠状病毒致命性感染病例,并认为该病例与不久前往沙特阿拉们的1例新型冠状病毒致命性感染相关,新型人冠状病毒（HCoV）致命性感染人类再次发生[1]。随即这种新型HCoV的全基因序列在GenBank中被公布．新的冠状病毒被命名为HCoV—EMC／20120。     

儿童急性下呼吸道感染病毒病原学分析

目的了解儿童急性下呼吸道感染病毒病原学特点。方法采用直接免疫荧光法(DIF),对2007年9月—2009年9月住院的5480例0～12岁下呼吸道感染患儿鼻咽分泌物进行8种病毒检测。结果5480例患儿中,2710例检出至少1种病毒,总检出率49.5%。呼吸道合胞病毒(RSV)检出最多,为1386例,占51.1%,其余,依次是偏肺病毒(hMPV)513例(18.9%),副流感病毒Ⅲ(PIVⅢ)338例(12.5%),腺病毒(ADV)192例(7.1%);流感病毒A(IFA)128例(4.7%),流感病毒B(IFB)79例(2.9%),副流感病毒Ⅰ(PIVⅠ)41例(1.5%),副流感病毒Ⅱ(PIVⅡ)33例(1.2%)。6个月以下年龄组阳性率最高,为43.5%。RSV、hMPV季节性较明显,主要集中在冬春季节(11月至次年4月)。肺炎、毛细支气管炎、支气管炎(伴喘息)、支气管炎(不伴喘息)和哮喘患儿病毒阳性率分别为47.4%、63.6%、50.5%、30.1%和43.5%。结论病毒是儿童急性下呼吸道感染的主要病原。发病年龄主要在婴幼儿,其中RSV和hMPV最常见。     

急性呼吸道感染住院儿童人类博卡病毒感染的临床特征

目的 了解西安地区以急性呼吸道感染住院患儿的人类博卡病毒(HBoV)感染的临床特征.方法 将2008年1月-12月以急性呼吸道感染住院患儿的咽拭及痰液标本252例分成2份,1份应用直接免疫荧光法检测RSV,甲、乙型流感病毒,Ⅰ、Ⅱ、Ⅲ型副流感病毒和腺病毒常见的7种呼吸道病毒;另1份用于提取HBoV DNA,分析HBoV感染的临床特点及流行病学特征.随机抽取1份HBoV DNA阳性扩增产物进行序列测定,并通过Clustal W软件与GenBank中其他HBoV序列进行多序列比对分析.结果 252份标本共检测到15份(6.0%)HBoV PCR阳性扩增产物.HBoV感染全年均有发生,冬春季多发;73.3%HBoV感染患儿的年龄为6个月至3岁;53.3%的患儿诊断为支气管肺炎(包括毛细支气管炎);53.3%患儿合并有其他呼吸道病毒的感染.HBoV单独感染与合并其他呼吸道病毒感染在临床特征方面无明显差别.HBoV NS1测序的291 bp与GenBank中2个原型株HBoV Stockholm 1(stl,No.DQ00495)、HBoY Stockholm2(st2,No.DQ00496)和北京的2株(No.DQ988934.2及No.DQ988933.1)的同源性为99.0%.结论 HBoV在15例以急性呼吸道感染住院患儿的咽拭及痰液标本中检出,HBoV感染以下呼吸道感染为著,与其他呼吸道病毒有较高的合并感染,HBoV单独感染与合并其他呼吸道病毒感染在临床特征方面无明显差别.     

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目的分析急性呼吸道感染住院患儿的病原学特点。方法对2005年10月至2009年9月苏州大学附属儿童医院呼吸科8172例急性呼吸道感染住院患儿,采用无菌负压吸引法采集其新鲜痰液,分别用直接免疫荧光法、RT-PCR检测7种常见病毒抗原和人类偏肺病毒基因(6599例),细菌培养检测细菌(6404例),ELISA法检测血清肺炎支原体(7842例),检出的阳性病例入选,分析其病例资料。结果 8172例标本中检出1种或1种以上病原4756例(58.2%),6404例细菌检测标本中阳性1883例(29.4%),6599例病毒检测标本中阳性1886例(28.2%),7842例肺炎支原体检测标本中阳性2630例(33.5%)。细菌病原中肺炎链球菌(10.8%)最多见。病毒中以呼吸道合胞病毒(15.8%)最常见。病原混合感染率为16.9%,以细菌及病毒混合感染为最常见。呼吸道合胞病毒冬季检出率最高,人类偏肺病毒冬春季、副流感病毒3夏季检出率较高,流感病毒A夏季检出率较低,肺炎支原体检出率夏秋季较高,冬春季较低;副流感病毒1,2季节差异不明显。结论肺炎支原体是本地区儿童急性呼吸道感染最常见的病原,病毒次之,细菌是混合感染的常见病原。细菌和病毒感染多见于1岁以下婴儿,而支原体感染多见于3岁以上儿童。各病原的流行季节各异。     

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??Abstract??Objective??To investigate the characteristics of adenovirus infection in children with acute respiratory tract infection. Methods??From May to June 2009?? 492 out-patients with acute respiratory tract infection were involved in our study. One throat swab specimen was collected from each patient. ??RT?? PCRs were performed to detect common respiratory tract viruses including respiratory syncytial virus ??RSV???? rhinovirus ??RV???? influzenza virus type A and B ??IFA?? IFB???? parainfluenza virus ??PIV?? type 1??4?? adenovirus ??AdV???? enterovirus ??EV???? human coronavirus ??HCoV???? human metapneumonia virus ??hMPV?? and human bocavirus ??HBoV??. AdV amplicons were cloned and sequenced to determine the AdV serotypes by using Blast and phylogenetic analysis. Results??At least one viral pathogen was detected in 165 out of 492 patients and the overall positive rate was 33.5%. AdV was detected in 53 ??10.8%?? specimens and it was the most common viral pathogen. Of the 53 AdV postive samples?? 3 subgroups and 7 serotypes were found. AdV serotype 3 ??23/53?? was the major serotype?? followed by serotype 7 ??8/53?? and serotype 1 ??7/53??. Conclusion??There were several AdV serotypes circulating in the spring of 2009 in Beijing area and serotype 3 was the predominant strain. AdV still playes an important role in acute respiratory tract infection in children.     

Chlamydia pneumoniae in children with acute respiratory tract infections

Children seeking medical attention for acute respiratory tract infections were investigated for evidence of Chlamydia pneumoniae infection. Blood samples were obtained from 367 children. Nasopharyngeal or throat swabs for PCR analysis (polymerase chain reaction) were taken from 360 children. Serology was found to be useful for diagnosis of infection only in children aged 5 y. Using PCR, a prevalence of 8 and 10% of C pneumoniae was found in male and female children aged < 2 y; 17 and 19%, respectively, in the age group 2-4 y and 32 and 21%, respectively, in the age group 5–16 y. We conclude that Chlamydia pneumoniae is a common finding in young children with respiratory tract infections. Younger children were more often found to have a moderate disease, but may have been ill for a long period.     

急性呼吸道感染住院患儿副流感病毒的检测及分析

目的分析温州地区急性呼吸道感染(ARI)患儿副流感病毒(PIV)的流行情况。方法采集2003年1月～2006年12月急性呼吸道感染住院患儿的鼻咽分泌物,应用直接免疫荧光法检测副流感病毒1、2、3型抗原。结果5731例标本中PIV阳性348例(6.1%),其中PIV165例(1.1%)、PIV26例(0.1%)、PIV3250例(4.4%)、混合感染27例(0.5%);2003～2006年PIV检出率分别为9.1%、5.7%、8.9%、2.0%(χ2=88.47,P<0.01);PIV3在≤1岁组检出率高于>1岁组(χ2=9.03,P<0.01)。结论2003年1月～2006年12月,温州地区ARI患儿中有PIV1、PIV2、PIV3及混合感染不同程度的流行,婴儿期易感。PIV3为优势流行株,2003～2005年几乎呈全年的流行态势,并且年度流行高峰不同,以夏季为多。     

The impact of passive smoking on the development of lower respiratory tract infections in children

Environmental tobacco smoke is an important public health problem. The objective of this study was to evaluate the effect of passive smoking on lower respiratory tract infections (LRTIs) in children aged 2-12 years. A case-control study was conducted on matched-pair design. One-hundred and fifty children with LRTIs and 150 healthy children were included in the study. Data were collected through questionnaire and urine samples for the determination of cotinine levels, and were analysed by McNemar chi-square, paired t-test and Pearson correlation tests. The prevalence of parental self-reported, indoor smoking was 71.3% in children with LRTI and 72.0% in healthy children. Employing 30 ng mg(-1), the cut-off level of urinary cotinine/creatinine as commonly accepted, 87.3% of the children with LRTIs and 84.7% of healthy children were found to be passive smokers (p = 0.61, odds ratio (OR) = 0.93; confidence interval (CI) = 0.34-2.53). If 60 ng mg(-1) of urinary cotinine/creatinine was accepted as a cut-off level, it was observed that the rates of passive smoking were 76.7% and 50.7%, respectively (p = 0.000, OR = 4.72; 95% CI = 2.62-8.52). Dose-dependent exposure to environmental tobacco smoke was found to be associated with the incidence of LRTI.     

7岁以下儿童急性下呼吸道感染病原学研究

目的 探讨苏州地区7岁以下儿童急性下呼吸道感染的痛原学分布.方法 对2007年10月至2008年3月间苏州大学附属儿童医院呼吸科住院患儿中7岁以下急性下呼吸道感染住院患儿810例,采用无菌负压吸引法采集新鲜痰液,进行细茵培养,直接免疫荧光法检测病毒,酶联免疫吸附试验(ELISA)法检测血清支原体、衣原体抗体.结果 810例患儿中556例病原栓测阳性(68.6%),单纯病毒感染181例(22.3%),单纯细菌感染124例(15.3%),单纯支原体感染72例(8.9%),单纯衣原体感染10例(1.2%),混合感染169例(20.9%).病毒以呼吸道合胞病毒为主(35.8%),细菌则以肺炎链球菌为主(13.8%),其次为流感嗜血杆菌(4.6%).结论 苏州地区7岁以下儿童急性下呼吸道感染最常见痛原是病毒,其次是细菌、支原体、衣原体.支原体感染多见于1岁以上儿童,混合感染则多见于3岁以下儿童.     

2000年秋冬至 2002年夏北京地区急性呼吸道感染病毒病原学研究

为了解北京地区婴幼儿急性呼吸道感染的病毒病原。对2000年秋冬至2002年夏收集的1402份临床标本进行了病原分析。所有标本接种Hep-2和MDCK细胞进行病毒分离；鼻咽洗液脱落细胞涂片后经间接免疫荧光检测7种呼吸道病毒。RT-PCR鉴定RSV亚型；血凝及血凝抑制试验鉴定流感病毒型别；nested-PCR检测肠道病毒。1402份标本中672份咽拭子标本取自门诊患儿，730份鼻咽洗液标本取自住院患儿，结果：共有614份标本为病毒阳性，阳性率为43.8%。病毒阳性标本中呼吸道合胞病毒（RSV）占66.1%。并以A亚型为主；RSV阳性标本中91.4%来自诊断为毛细支气管炎的住院患儿。2001-2002年冬春季RSV感染比2000-2001年同期高25.1%。流感病毒阳性标本占总阳性标本的24.4%，其中89.3%来自门诊患儿；2000-2001年以乙型流感病毒为主，2001-2002年以甲3型为主，在冬春季还可检测到腺病毒和副流感病毒，夏季检测不到以上几种呼吸道病毒，利用nested-PCR方法检测2002年夏季收集的标本，发现7月份肠道病毒感染率相当高。提示RSV是北京地区冬春季婴幼儿急性下呼吸道感染首要病毒病原。流感病毒是婴幼儿急性上呼吸道感染首要病毒病原，肠道病毒是夏季婴幼儿呼吸道感染主要病毒病原，病毒分离，免疫荧光和PCR等方法的并用提高了病毒检出率，病毒病原的诊断可为临床诊断和治疗提供可靠依据。     

小儿急性呼吸道感染流感嗜血杆菌耐药性研究

为了解上海地区小儿急性呼吸道感染 (ARTIs)时流感嗜血杆菌(Hi)的分离率、产酶率以及b型Hi(Hib)感染的情况 ,并了解Hi对8种常用抗菌药物的耐药性 ,收集812例呼吸道感染患儿的鼻咽分泌物进行Hi分离培养 ,以Nitrocefin纸片法测定β_内酰胺酶的产生率 ,以玻片凝集法分离出b型株 ,用Kirbry_Bauer(KB)法和E_test法测定Hi对8种抗菌药物的耐药率。结果显示 ,Hi分离率24.7 %,其中Hib占19% ;平均β_内酰胺酶产生率9 % ,其中Hib产酶率36.8 % ,明显高于非Hib产酶率2.5 %(P<0.01)。Hi对第2、第3代头孢类抗生素、阿莫西林/克拉维酸均十分敏感 ,对氯霉素、氨苄西林的耐药率分别为11.5%和9.5 % ,而对四环素、复方新诺明(SMZco)的耐药率分别达到16.1 %和45.6%。提示Hi是小儿ARTIs的重要病原菌之一 ,Hi对氨苄西林、氯霉素、四环素和SMZco的耐药在增加 ,产β_内酰胺酶是Hi耐药的重要机制 ,而Hib的产酶率显著高于非Hib株     

Drug-resistant pneumococci in children with acute lower respiratory infections in Vietnam

Background: Acute lower respiratory infections (ALRI), primarily pneumonia, are the leading cause of death in children under 5 years of age. Most of these deaths occur in Africa and southeast Asia. Increasing rates of drug resistance in pneumococcal strains emphasize the necessity of prevention of pneumococcal vaccines. The aim of the present study was to determine the frequency of drug resistance and the distribution of serotype of pneumococcal strains isolated from pediatric patients with ALRI in Vietnam.
Methods: Two hundred and twenty pediatric patients with ALRI under 5 years of age were enrolled in Hanoi, Vietnam between 2001 and 2002. Bacterial pathogens with a heavy growth (10⁶ c.f.u./mL) were isolated from nasopharyngeal secretions on quantitative culture. Fifty-three pneumococcal strains isolated from the nasopharynx of pediatric patients were examined for antibiotic susceptibility including drug-resistant genes and serotyping.
Results: A total of 73.6% of pneumococcal strains were genotypic penicillin-resistant Streptococcus pnemoniae (gPRSP), possessing altered penicillin-binding protein genes pbp 1a   +   2x   +   2b ; 67.9% of these strains were gPRSP and simultaneously had the ermB gene, which is responsible for high resistance to erythromycin. The majority of gPRSP strains were serotype 19F or 23F.
Conclusion: gPRSP strains with serotype 19F or 23F are highly prevalent among pediatric patients with ALRI under 5 years of age in Hanoi, Vietnam.