Practical approach to catheter-related bloodstream infections in paediatrics

Catheter-related bloodstream infections (CRBIs) are a common problem in paediatrics. Sterile insertion and proper care of the catheter is likely more important than the type of catheter in determining the rate of CRBIs. The accuracy of the diagnosis of CRBIs can be improved by comparing the time to positivity or the concentration of organisms in blood drawn through the catheter with blood drawn from other sites, or by changing the catheter over a guidewire and culturing the removed catheter. When a CRBI is suspected, the catheter should be removed if it is no longer required, the child is hemodynamically unstable, there are metastatic foci of infection, the infecting organism is Candida or a mycobacterium, or there is a tunnel infection. The necessity for catheter removal is controversial if the infecting organism is Staphylococcus aureus or a Gram-negative organism. In most other situations, the catheter only needs to be removed if bacteremia persists despite appropriate antibiotic use.     

Neonatal nosocomial respiratory infection with coronavirus: a prospective study in a neonatal intensive care unit

The aim of this prospective study was to evaluate the incidence of viral respiratory infection in hospitalized premature newborn infants and to assess the role of coronaviruses. All hospitalized premature infants with a gestational age less than or equal to 32 weeks were included. Tracheal or nasopharyngal specimens were studied by immunofluorescence for coronaviruses, respiratory syncytial virus, adenoviruses, influenza and parainfluenza viruses. Forty premature infants were included; 13 samples were positive in 10 newborns (coronaviruses n = 10; influenza 1 n = 2; adenovirus n = 1). None was positive at admission. All premature infants infected with coronaviruses had symptoms of bradycardia, apnea, hypoxemia, fever or abdominal distension. Chest X-ray revealed diffuse infiltrates in two cases. However, no significant difference was observed between infected and non-infected premature infants for gestational age, birth weight, duration of ventilation, age at discharge, incidence of apnea or bradycardia. Nosocomial respiratory tract infection with coronaviruses appears to be frequent. The clinical consequences should be evaluated in a larger population.     

Pathology of Opportunistic Infections in Children with Acquired Immune Deficiency Syndrome

Opportunistic infections (OI) were diagnosed by histology and culture of biopsy and autopsy material in 15 children with the acquired immune deficiency syndrome (AIDS). The opportunistic pathogens included Pneumocystic carinii, Toxoplasma gondii, Candida species, Aspergillus species, Mycobacterium avium-intracellulare, cytomegalovirus, and herpes simplex virus. Seven of 15 patients also had multiple systemic infections with common pathogenic bacteria. Accurate diagnosis of OI in AIDS is of importance in the decision regarding the choice of appropriate antimicrobial therapy. Careful histologic assessment of the biopsy specimens; awareness of unusual features such as paucity of organisms and inflammatory reaction, “histoid” variety of reaction, lack of granuloma formation, and resemblance to Whipple's disease in certain OI; and demonstration of causative organisms by appropriate special stains andlor culture are essential in the evaluation of these patients.     

1978—1996年广州地区呼吸道合胞病毒感染分析

为了解广州地区儿童呼吸道合胞病毒（ＲＳＶ）感染的情况，采用病毒分离等方法，对广州地区１９７８～１９９６年连续１８年的儿童支气管炎和支气管肺炎进行了ＲＳＶ病原学检测。共检测患儿５２７３例，分离出ＲＳＶ的患儿５１３例。病毒分离总阳性率９．７％。１８年中以１９８５年、１９８６年和１９９２年ＲＳＶ分离率最高；一年中ＲＳＶ分离率从３月份开始增高，４月份达高峰，持续至５～８月，９月份开始下降。结论：１８年来广州地区有过３次ＲＳＶ感染流行高峰（１９８５年、１９８６年、１９９２年）；广州地区ＲＳＶ感染的流行季节主要发生在每年的春夏季。     

下呼吸道感染患儿外周血单个核细胞呼吸道合胞病毒感染的研究

为探讨呼吸道合胞病毒（ＲＳＶ）对外周血单个核细胞（ＰＢＭＣ）的感染情况及感染后细胞免疫的变化，采用免疫组化法对１８例ＲＳＶ性急性下呼吸道感染患儿ＰＢＭＣ内ＲＳＶ及其Ａ、Ｂ亚型抗原进行了检测；采用ＡＰＡＡＰ法、ＭＴＴ比色法和ＥＬＩＳＡ法对Ｔ细胞亚群及Ｔ细胞表面白细胞介素２受体表达、ＰＢＭＣ培养上清液白细胞介素２（ＩＬ－２）活性和可溶性ＩＬ－２受体水平进行了测定。结果显示：１８例ＲＳＶ感染患儿中７例ＰＢＭＣ内可检测到ＲＳＶ抗原；１１例ＲＳＶＡ亚型感染者５例ＰＢＭＣ内均为ＲＳＶＡ亚型阳性，７例ＲＳＶＢ型感染者２例Ｂ亚型阳性；７例恢复期和１０例对照组患儿均为阴性；发病３天以内ＰＢＭＣ中ＲＳＶ抗原阳性者多于３天以后（Ｐ＜０．０５）。ＲＳＶ感染组ＰＢＭＣ内ＲＳＶ抗原阳性者，ＣＤ４细胞比率和ＩＬ－２水平均低于阴性者（ｔ＝２．３８，２．４０，Ｐ值均＜０．０５）。提示：ＲＳＶ性急性下呼吸道感染患儿ＰＢＭＣ可被ＲＳＶ感染，可能由此加重免疫活性细胞损害，导致细胞免疫功能紊乱。     

北京地区急性呼吸道感染婴幼儿中人副流感病毒感染状况的研究

目的了解北京地区急性呼吸道感染患儿中人副流感病毒（HPIV）的感染状况。方法（1）根据HPIV血凝素蛋白（HA）的基因保守区序列,合成能够区分HPIV 1～4型的多重巢式PCR引物,并用多种呼吸道病毒的标准毒株确定多重PCR方法的特异性;（2）收集2003年8月-2006年4月急性呼吸道感染患儿的临床标本3519例,应用逆转录多重PCR方法,对标本同时进行HPIV 1～4的检测。（3）随机选取不同型别的HPIV基因检测阳性标本共10例,对其PCR扩增产物直接进行核苷酸序列测定,并将所测到的序列与GenBank中的基因序列进行比较。结果（1）多重PCR方法的特异性检测显示,HPIV的分离株cDNA有预期大小的扩增片段,与其他常见呼吸道病毒无交叉反应性。（2）3519例标本中多重PCR检测阳性的为349例,占本组检测标本的9．9％（349／3519）,明显高于间接免疫荧光方法和（或）病毒分离4．8％的阳性率（170／3519）;应用多重PCR方法还检测到HPIV1与HPIV3以及HPIV3与HPIV4的混合感染;在上呼吸道及下呼吸道感染的患儿中均有较高的HPIV阳性检出率;季节性分布分析显示,HPIV感染无明显的规律性,以HPIV1、3为主,HPIV2、4仅散发存在。（3）序列分析结果提示,所选取的多重PCR方法检测阳性的10例标本确实是HPIV阳性,其中有两份分别属于HPIV4A、4B亚型。结论HPIV在儿童感染中除了单．亚型感染外还可存在混合型感染。未发现其感染的季节性特点。所应用的逆转录多重RT-PCR方法不仅检出率高于常用的方法（间接免疫荧光方法和病毒分离）,而且能够直接进行亚型分析。除了检出常见的1、2、3型外,还检出了较少见的4型,属国内首次报道。     

儿童下呼吸道流感嗜血杆菌感染的临床调查

为了解小儿急性下呼吸道感染中流感嗜血杆菌（ＨＩ）的致病情况，采用改良的哥伦比亚巧克力琼脂培养基，对１３８例门、急诊下呼吸道感染患儿痰标本和１８１名健康儿童咽拭子进行分离培养；对检出的４０株ＨＩ分离株作生化分型；随机选择１６例ＨＩ阳性患儿作自身ＨＩ分离株的血清凝集试验。结果痰标本中致病菌检出率４２．０％（５８／１３８），ＨＩ阳性率２９．０％居首位，其次为肺炎链球菌４．３％。学龄组中患儿ＨＩ感染率２３．９％，健康儿童ＨＩ携带率２０．９％，ＨＩ均以生物Ⅰ，Ⅱ，Ⅲ型为主；学龄前组中患儿ＨＩ感染率３３．８％，健康儿童ＨＩ携带率３７．９％，均以生物Ⅵ型占优势。凝集试验阳性率８１．２％，健康对照组均为阴性。提示小儿下呼吸道感染病原菌以ＨＩ为主，健康儿童口咽部ＨＩ具有致病倾向。     

新生儿支原体感染情况的初步观察

为了探讨致病性支原体对新生儿的影响，采用间接血细胞凝集方法检测了３２３例住院新生儿血清中支原体特异抗体。结果：３２３例中５６例阳性，阳性率１７．３％。其中解脲脲原体２６例，阳性率４６．４％，人型支原体１６例，占２８．６％，二者合计４２例，占７５．０％。３３例做了双份血清抗体检测，１７例抗体阳性，并且两次间抗体滴度有变化，其中９例阳性转为阴性，７例阴性转为阳性，１例滴度继续升高。检测了１９例早产儿，阳性６例，阳性率３１．６％。所有支原体抗体阳性新生儿未见特异症状和体征，与原病种无明显关系。提示：新生儿对支原体的感染，以解脲脲原体和人型支原体为主，早产儿感染率相对较高。由于感染和检测时间的早晚，一次抗体阴性不能除外支原体感染。     

人类博卡病毒感染的持续喘息患儿临床特点分析

目的探讨人类博卡病毒（HBoV）感染的持续喘息患儿临床特点。方法从2006年4月至2007年1月共收集39例持续喘息患儿的呼吸道分泌物标本,其中33例通过纤维支气管镜检查吸取下呼吸道分泌物,6例为鼻咽分泌物。先进行呼吸道常见7种病毒筛查,并采用PCR的方法检测HBoV基因片段,对检出的阳性标本进行测序分析。结果（1）用免疫荧光快速诊断的方法在39例持续喘息患儿呼吸道分泌物中共检出呼吸道合胞病毒阳性13例,腺病毒阳性9例,副流感病毒3阳性4例,流感病毒A阳性2例。对检出的13例RSV阳性的标本进行病毒分离培养后提取RNA,RT-PCR进行呼吸道合胞病毒检测,检出8例阳性。（2）PCR和测序均证实,39例患儿呼吸道分泌物标本中有12例检出HBoV阳性。（3）12例HBoV阳性标本中的10例收集于冬春季,其余2例收集于夏秋季,与RSV的流行季节相似。（4）12例HBoV阳性患儿中7例出现发热,其中高热5例,明显高于RSV感染的患儿（1／13）,其胸X线改变出现间质性改变的例数也多于RSV感染患儿。其他如咳嗽、喘息、呼吸困难等临床表现两者差异均无统计学意义。结论HBoV感染是引起小儿下呼吸道感染的重要病毒病原之一,首次发现在持续喘息的患儿呼吸道分泌物中HBoV的阳性率高达31％。与RSV感染的患儿相比,HBoV感染发热例数相对多,但其他的临床症状与RSV相似。     

流感嗜血杆菌b型与急性呼吸道感染关系的研究

目的进一步了解急性呼吸道感染中流感嗜血杆菌（ＨＩ）感染的发病情况。方法采用单克隆抗体夹心酶联免疫吸咐法，对３６例上呼吸道感染、３２例支气管炎、７０例肺炎患儿及４５例健康对照组的血、尿进行ｂ型ＨＩ外膜蛋白（ＨｉｂＯＭＰ）抗原的检测，并对７０例肺炎患儿的血清进行ＨｉｂＯＭＰ抗体检测。结果３６例上呼吸道感染患儿中有４例为ＨｉｂＯＭＰ抗体阳性，３２例支气管肺炎患儿中有４例阳性，７０例肺炎患儿中有１８例为阳性；４５例健康对照组中仅１例为ＨｉｂＯＭＰ抗原阳性。肺炎组抗原检出率高于对照组（χ２＝１０．９６０，Ｐ＜０．０１）。７０例肺炎中１８例ＨｉｂＯＭＰ抗体阳性。抗原、抗体检测共有２４例（包括抗原、抗体均阳性１２例，仅抗原或抗体阳性各６例）肺炎获得阳性结果。结论１１．１％的上呼吸道感染、１２．５％支气管炎和３４．３％的肺炎患儿为Ｈｉｂ感染；抗原、抗体联合检测可使Ｈｉｂ检出率提高。     

Fluconazole for treatment of fungal infections of the urinary tract in children

Two children with fungal urinary tract infections (UTI) were treated with fluconazole. One had bilateral megaureters, an almost non-functioning right kidney, and a moderately functioning left kidney because of severe vesicoureteric reflux. He underwent a ureteric reimplantation procedure but developed a fungal UTI postoperatively. The other child had bilateral refluxing megaureters, one of which appeared to open ectopically into the urethra. He acquired a fungal infection during intensive and prolonged antibiotic therapy for a bacterial UTI and septicaemia in the neonatal period. Both fungal infections were cured successfully. We recommend fluconazole as a safe and effective antifungal agent that may be used as a drug of choice for this difficult problem.     

Qualitative versus quantitative blood cultures in the diagnosis of catheter-related bloodstream infections in children with malignancy

BACKGROUND: Paired quantitative and qualitative blood cultures have been introduced for the diagnosis of catheter-related bloodstream infections (CRBI) with the catheter in situ. The aim of the study was to compare the diagnostic performance and the prognostic value of the two methods in the evaluation of febrile episodes without an apparent source in children with cancer. PROCEDURE: During a 4-year period, in every febrile episode without an apparent focus, blood was drawn simultaneously from the catheter lumen and a peripheral vein in order to perform paired quantitative (Isolator) as well as qualitative (BacT/Alert) blood cultures. The diagnosis of a CRBI was defined as either a case of greater (at least 10 fold) or earlier (differential time to positivity >2 h) bacterial growth from the catheter compared to the peripheral blood sample, respectively. RESULTS: Nineteen febrile episodes manifested in 16 children (total period of observation 11,150 catheter-days) were evaluated with both methods. A concordant diagnosis of CRBI was stated with both methods in six episodes; one episode was diagnosed as CRBI only with qualitative culture criteria. Treatment failure resulted in catheter removal in five out of the seven episodes defined as CRBI with either method. Episodes where a CRBI was ruled out with both methods had a favorable outcome. CONCLUSIONS: In this study the two methods showed comparable results in the diagnosis of CRBI and both were of prognostic significance, regarding the outcome of the treatment. However, large scale studies are required in order to evaluate the clinical relevance and the cost effectiveness of performing routinely paired blood cultures with either method.     

携带Panton-Valentine杀白细胞素基因金黄色葡萄球菌致新生儿软组织化脓性感染三例

目的 研究引起新生儿软组织化脓性感染的病原菌.方法 常规方法分离细菌,全自动微生物分析仪进行菌种鉴定和药物敏感试验,多重PCR检测Panton-Valentine杀白细胞素基因,用另一种多重PCR检测SCCmec基因型,采用多位点测序技术检测基因序列型.结果 2例从软组织化脓性感染的新生儿从其脓液中分离出2株金黄色葡萄球菌,另1例从其血液和脓液中分别分离出2株金黄色葡萄球菌.4株金黄色葡萄球菌都为携带PVL基因的耐甲氧西林金黄色葡萄球菌,SCCmec基因型都为SCCmec ⅢA型,序列型为ST88,4株MRSA除红霉素外,其余耐药谱相同.结论 3例新生儿的软组织化脓性感染是由携带PVL杀白细胞素的MRSA同一克隆株引起,该克隆株为ST88-SCCmecⅢA-MRSA.     

The cephalosporin compounds in severe neonatal infection

The new cephalosporin compounds have increased in vitro activity against gram-negative enteric bacilli and penetrate well into cerobrospinal fluid. Moreover, their pharmacokinetic properties are favorable and their safety seems adequate, although insufficiently evaluated to date. Interest has been focused on them as therapeutic agents for neonatal sepsis and meningitis caused by Enterobacteriaceae. In this review the third generation cephalosporins are evaluated for their possible use in the neonates; opinions are based on currently available data. It is concluded that moxalactam and cefotaxime and probably also ceftriaxone and ceftazidime represent valuable alternatives to aminoglycosides for therapy of severe neonatal infection. Curriculum vitae. Urs B. Schaad was born 1945 in Switzerland. He graduated 1971 from the Medical Faculty of the Bernese University and his postgraduate training included 1 year General Surgery (Lugano), 11/2 years Internal Medicine (Langenthal) and 41/2 years Pediatrics (Berne). From 1978 to 1980 he completed a Research Fellowship in Pediatric Infectious Diseases at the University of Texas at Dallas, USA (Directors of Program: Prof. George H. McCracken, Jr., and Prof. John D. Nelson). Since 1981 he is back at the Department of Pediatrics, University of Berne (Head: Prof. E. Rossi), conducting clinical, research and teaching activities in Pediatric Infectious Diseases. In June 1983 he was promoted to Privatdozent and received the Venia Docendi in Pediatrics with special regard to Infectious Diseases. Main topics of research have been experimental meningitis and studies on pharmacokinetics and efficacy of different antimicrobial agents in pediatric patients. Previous reviews included recrudescence and relapse in bacterial meningitis, atypical myobacterial lymphadenitis, melioidosis, pyogenic sacroiliitis, arthritis in meningococcal disease, infantile chlamydial pneumonia, Campylobacter-reactive arthritis, prophylaxis against pneumococcal, meningococcal and H. influenzae type b infections in childhood, neonatal sepsis and meningitis, and infectious diarrhea in the pediatric age group.     

Clinical manifestations of human coronavirus NL63 infection in children in Taiwan

Human coronavirus NL63 (HCoV-NL63) is a global respiratory tract pathogen; however, the epidemiology of this virus in subtropical area is not well known. To evaluate the epidemics and disease spectrum of HCoV-NL63 infection in children in Taiwan, we prospectively screened children admitted to the hospital with respiratory tract infection from May 2004 to April 2005. Every enrolled child had a nasopharyngeal aspirate (NPA) sample taken. Quantitative RT-PCR was used to detect 1b gene of HCoV-NL63. A total of 539 NPAs were collected. Seven (1.3%) were positive for HCoV-NL63. All cases were boys younger than 3 years of age and most cases occurred in autumn. Co-infection with other pathogens was observed in three cases. The most common symptoms/signs of HCoV-NL63 infection were cough, fever, and inspiratory stridor. HCoV-NL63 was the most common pathogen (14.7%) in children with croup and was the cause of three cases of croup in October. The odds ratio of croup in children infected with HCoV-NL63 was 43.4 (95% CI 8.1∼233.1). In conclusion, HCoV-NL63 is an important respiratory tract pathogen as the main cause in children admitted to the hospital in Taiwan.     

Day care in relation to respiratory-tract and gastrointestinal infections in a German birth cohort study

AIM: To describe day care attendance in Germany today (in former East and former West Germany). To investigate longitudinally whether children attending day care centres have an increased risk of acquiring common cold, bronchitis, pneumonia, otitis media or diarrhea. METHODS: Questionnaire information was collected when the children in the cohort were 6, 12, 18, 24 months, and 4 and 6 years old. Day care within the first and first 2 years of life was investigated longitudinally with GEE (generalised estimating equations) methods in relation to common cold, bronchitis, pneumonia, otitis media and diarrhea within the first 6 years of life. RESULTS: Day care centre attendance is more common in former East than in former West Germany; this difference is evident even 10-12 years after German reunification. Children attending a day care centre were more likely to have common cold, bronchitis, pneumonia, otitis media and diarrhea within the first 2-3 years of life. With the exception of common cold, from year 4 onwards these associations were not statistically significant anymore and even reversed for some of the infections. CONCLUSIONS: Children attending day care centres were at an increased risk of respiratory and gastrointestinal infections within the first years of life. However, around school age these differences disappeared or even partly reversed.     

Lower respiratory tract infections and gastrointestinal infections among mature babies in Japan

Background: Epidemiologic evidence regarding the background factors of childhood infections in Japan is scarce. The aim of the present study was therefore to investigate the rates and associated factors of hospitalization for lower respiratory tract infections (LRTI) and gastrointestinal infections (GII) among children with birthweight ≥2500 g and ≥37 weeks of gestational age. Method: The data for the study were collected at 18‐month health checkups in one city in Japan. The community database included information on the main outcome (past hospitalization) and 16 host, environmental, and parenting factors. The Kaplan–Meier method and log–rank test were used to determine sex differences in hospital admission for infection, and the Cox regression model to analyze sex‐specific factors associated with the hospitalization. Results: The proportion of children who were admitted to hospital before their 18‐month checkup was 7.1% for LRTI and 2.2% for GII. Hospital admission for LRTI among boys was higher than girls. Multivariate analysis indicated the following LRTI‐associated factors: child‐care attendance (hazard ratio [HR]= 1.97) and three or more adults living together (HR = 2.63) for boys; and child‐care attendance (HR = 4.30) and two or more children living together (HR = 4.57) for girls. GII‐associated factors were maternal age <25 years (HR = 3.45) for boys, and hand washing by caregivers after lavatory use and diaper changing (HR = 6.93) for girls. Conclusions: One out of 11 children was hospitalized because of LRTI or GII during their first 18 months, which was associated with a biologic factor (sex), environmental factors (child‐care attendance and family size), and parenting practices (shorter duration of exclusive breast‐feeding and caregivers' unfavorable hygiene practices).     

小儿胃幽门螺杆菌感染诊断方法的研究

为探讨小儿幽门螺杆菌（ＨＰ）感染诊断的最佳手段，对９８例不同群体小儿用胃粘膜活检标本尿素酶快速诊断法、血清ＨＰ－ＩｇＧ测定法、胃液ＨＰ－聚合酶链反应（ＰＣＲ）法进行了ＨＰ感染的对比性研究。结果：三种方法在上消化道疾病组胃粘膜活检标本中ＨＰ感染阳性率分别为４２％、５４％、４８％，与非消化道疾病及健康小儿对照组差异有显著性意义（Ｐ＜０．００５）。结果表明：三种方法在检测ＨＰ的阳性率方面无明显差别，而胃液ＨＰ－ＰＣＲ法方法简单实用、敏感性和特异性均较好，可作为诊断ＨＰ感染的最佳方法之一。     

Therapy of infections in neutropenic patients: Results with gentamicin in combination with cephalothin or chloramphenicol

Gentamicin in combination with cephalothin (Gent-Ceph) or with chloramphenicol (Gent-Chloro) was utilized in the treatment of 55 infections occurring in 49 cancer patients. Responses were obtained in 78% of the infections treated with Gent-Ceph and in 64% of those treated with Gent-Chloro. Pneumonia and septicemia were the most common infections in this study. Among the cases of pneumonia, 64% responded to Gent-Ceph and 67% to Gent-Chloro. Among the cases of septicemia, 88% responded to Gent-Ceph and 50% to Gent-Chloro. All of the identified organisms producing infection were gram-negative bacilli. Of these, E. coli was the most common. All organisms were resistant to cephalothin in vitro, and only 41% of them were resistant to chloramphenicol. However, resistant organisms responded significantly better to the Gent-Ceph combination (p < 0.025). Also, response to therapy among patients with severe neutropenia (< 100 neutrophils/mm³) was better for those patients treated with Gent-Ceph (p = 0.07). The combination of gentamicin with cephalothin or with chloramphenicol did not increase the frequency of side effects expected from gentamicin alone. No significant hematological toxicity was seen among those patients treated with chloramphenicol. Gentamicin in combination with cephalothin or chloramphenicol is an effective and safe antibiotic combination against gram-negative bacilli infections occurring in cancer patients. The efficacy of Gent-Ceph in patients with severe neutropenia is particularly advantageous.