新发现呼吸道病毒感染的流行病学及其临床特征

呼吸道感染是儿科的常见病、多发病,是引起世界范围内5岁以下儿童死亡的首位原因.其临床表现易被认识,但病因却很难明确.2001年以来许多新的人类病毒被发现,其中人类偏肺病毒、人类冠状病毒NL63和HKU1,以及人类博卡病毒,均已被证实可引起小儿呼吸道疾病,其流行病学及临床特征也得到较为深入的研究.     

Viral etiology of acute respiratory infections with cough in infancy: a community-based birth cohort study

BACKGROUND: Acute respiratory infections (ARI) are a major cause of morbidity in infancy worldwide, with cough and wheeze being alarming symptoms to parents. We aimed to analyze in detail the viral aetiology of ARI with such symptoms in otherwise healthy infants, including rhinoviruses and recently discovered viruses such as human metapneumovirus (HMPV), coronavirus NL63 and HKU1, and human bocavirus (HBoV). METHODS: We prospectively followed 197 unselected infants during their first year of life and assessed clinical symptoms by weekly standardized interviews. At the first ARI with cough or wheeze, we analyzed nasal swabs by sensitive individual real time polymerase chain reaction assays targeting 16 different respiratory viruses. RESULTS: All 112 infants who had an ARI had cough, and 39 (35%) had wheeze. One or more respiratory viruses were found in 88 of 112 (79%) cases. Fifteen (17%) dual and 3 (3%) triple infections were recorded. Rhino- (23% of all viruses) and coronaviruses (18%) were most common, followed by parainfluenza viruses (17%), respiratory syncytial virus (RSV) (16%), HMPV (13%), and HBoV (5%). Together rhinoviruses, coronaviruses, HMPV, and HBoV accounted for 60% (65 of 109) of viruses. Although symptom scores and need for general practitioner (GP) consultations were highest in infants infected with RSV, they were similar in infants infected with other viruses. Viral shedding at 3 weeks occurred in 20% of cases. CONCLUSIONS: Rhinoviruses, coronaviruses, HMPV, and HBoV are common pathogens associated with respiratory symptoms in otherwise healthy infants. They should be considered in the differential diagnosis of the aetiology of ARI in this age group.     

Human coronavirus NL63 associated with lower respiratory tract symptoms in early life

Coronavirus NL63 has been identified as a new member of the coronavirus genus, but its role as a cause of respiratory disease needs to be established. We studied the first episode of lower respiratory tract symptoms in a cohort of healthy neonates. NL63 was identified in 6 (7%) of 82 cases and was as frequent as other coronaviruses (9%). NL63 was recovered at the onset of symptoms and was cleared within 3 weeks in half of the cases. Our data suggests that coronavirus NL63 causes lower respiratory tract symptoms and is acquired in early life.     

Human coronavirus OC43 pneumonia in a pediatric cancer patient with down syndrome and acute lymphoblastic leukemia

In this report, we describe a case of pneumonia due to an infection with human coronaviruses (HCoVs)-OC43 in a pediatric leukemia patient with Down syndrome and febrile neutropenia. Not only the recently discovered HCoVs NL63 or HKU1 but also the prototype strains HCoV-OC43 and HCoV-229E have to be considered as respiratory pathogens in immunocompromised pediatric cancer patients. The routine utilization of polymerase chain reaction-based diagnostic tools would certainly elucidate the etiology of a relevant proportion of "pneumonias of unknown origin" in immunocompromised pediatric patients and would contribute to a better understanding of the role of HCoVs in this setting.     

SARS in newborns and children

The severe acute respiratory syndrome (SARS) is a highly contagious infection caused by a newly discovered strain of coronavirus (SARS-CoV). Infants born to pregnant women with SARS did not appear to acquire the infection through vertical transmission. Some newborn infants, however, developed severe intrauterine growth retardation and life-threatening gastrointestinal complications. It is now known that the clinical course and prognosis are different between paediatric and adult SARS patients. Young children (< 12 years), in general, run a less aggressive clinical course than do teenage and adult patients. Thus far, no fatalities have been reported in the paediatric age group (< or =18 years). This review describes the current understanding of the clinical manifestations, diagnostic tests, immunological profiles, patient management and outcomes of SARS-CoV infection in the paediatric population.     

基因检测在儿童严重急性呼吸综合征疑似病例诊断中的应用

目的 通过病原学检测鉴别诊断严重急性呼吸综合征(SARS)。方法 对1例没有明确SARS接触史,入院时临床诊断疑为“支原体肺炎”的患儿进行病原学鉴别诊断。(1)对患儿的咽拭子标本进行常见呼吸道病毒(包括呼吸道合胞病毒、甲、乙型流感病毒、腺病毒和I、Ⅱ、Ⅲ型副流感病毒)的抗原检测。(2)用RT-PCR进行人类偏肺病毒、肠道病毒和鼻病毒的检测。(3)采用巢式RT-PCR方法,进行SARS病毒基因检测。根据WHO在网上公布的SARS冠状病毒复制酶基因1b区合成3对引物,其中I对为所有冠状病毒所保守的,用来进行第一次PCR,另2对为SARS冠状病毒所特异的,分别用于第二次PCR,这2对引物可分别扩增368和348bp的基因片段。结果 患儿咽拭子标本7种常见呼吸道病毒和人类偏肺病毒、肠道病毒和鼻病毒的检测结果均为阴性,而用不同引物对检测,SARS冠状病毒基因均为阳性。经测序显示,该基因片段与GenBank已公布的17株SARS冠状病毒的序列同源性为100％,而与人冠状病毒的标准株有很低的同源性。同时该患儿的恢复期血清SARS冠状病毒特异性IgM和IgG均为阳性。结论 从患儿标本中未检测到常见的7种呼吸道病毒、人类偏肺病毒、肠道病毒和鼻病毒,而检测到了SARS冠状病毒。经病原学检测,确诊患儿为SARS,,在SARS流行期间,用检测常见呼吸道病毒抗原或基因的方法,可以将儿科的急性呼吸道病毒感染与SAPS进行区别。     

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.     

A young infant with severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS), a new contagious respiratory disease associated with a novel coronavirus, has spread worldwide and become a global health concern after its first outbreak in Guangdong Province of the People's Republic of China in November 2002. The clinical presentation and the radiologic, hematologic, biochemical, and microbiologic findings of a 56-day-old male infant with SARS are described. Some clinical and laboratory features are similar to those reported in adult and pediatric patients. However, this infant had a more severe clinical course as compared with the older children. This is the youngest patient with symptomatic SARS reported to date.     

Severe acute respiratory syndrome (SARS)

Several cases of life threatening respiratory disease with no identifiable cause were reported from Guangdong Province, China; these were soon followed by reports from many other countries. The disease was named as severe acute respiratory syndrome (SARS). A novel coronavirus, isolated from the respiratory secretions of patients, has been implicated in the causation of SARS. The modes of transmission include droplet spread, close contact, and Fomites; shedding of virus from respiratory tract is the primary mode of transmission. SARS clinically presents with high-grade fever, chills and rigors, myalgia, headache, cough with or without sputum production, dyspnea, and dizziness. Chest radiographs reveal unilateral or bilateral, predominantly peripheral, areas of consolidation progressing with in a short time of bilateral patchy consolidation. Preliminary reports suggest a milder illness in young children. The case definition of probable SARS cases, laboratory investigations and precautions for prevention of spread are discussed.     

The chronology of the 2002-2003 SARS mini pandemic

Severe acute respiratory syndrome (SARS) was a new human disease in the autumn of 2002. It first occurred in Southern China in November 2002 and was transported to Hong Kong on February 21, 2003 by an infected and ill patient. Ten secondary cases spread the infection to two hospitals in Hong Kong and to Singapore, Toronto and Hanoi. In March 2003 a novel coronavirus (SARS-CoV) was found to be the causative agent. Within 11 weeks from the first SARS case in Hong Kong it had spread to an additional 27 countries or special administrative regions. The mini pandemic peaked during the last week of May 2003 and the last new probable case was on July 13, 2003. There were a total of 8096 probable cases and 774 deaths. Sixty-six per cent of the cases occurred in China, 22% in Hong Kong, 4% in Taiwan and 3% in both Singapore and Canada. Twenty-one per cent of all cases occurred in healthcare workers.     

The cell biology of acute childhood respiratory disease: therapeutic implications

Respiratory syncytial virus (RSV), the recently identified human metapneumovirus (HMPV), and the human parainfluenza viruses (HPIVs), cause most cases of childhood croup, bronchiolitis, and pneumonia. Influenza virus also causes a significant burden of disease in young children, although its significance in children was not fully recognized until recently. This article discusses pathogens that have been studied for several decades, including RSV and HPIVs, and also explores the newly identified viral pathogens HMPV and human coronavirus NL63. The escalating rate of emergence of new infectious agents, fortunately meeting with equally rapid advancements in molecular methods of surveillance and pathogen discovery, means that new organisms will soon be added to the list. A section on therapies for bronchiolitis addresses the final common pathways that can result from infection with diverse pathogens, highlighting the mechanisms that may be amenable to therapeutic approaches. The article concludes with a discussion of the overarching impact of new diagnostic strategies.     

Human bocavirus: clinical significance and implications

PURPOSE OF REVIEW: Human bocavirus (HBoV), a parvovirus, was discovered in 2005 with the use of nonspecific genome amplification techniques. Since its discovery, HBoV has been identified worldwide. This review will focus on the epidemiology and clinical features associated with HBoV infection. RECENT FINDINGS: Initial studies demonstrated the presence of HBoV DNA in respiratory specimens of individuals with respiratory tract disease. Data from some studies suggest that HBoV may be the etiological agent responsible for respiratory tract disease, particularly in young children. HBoV, however, is frequently detected in the presence of other common respiratory viruses. HBoV is not confined to the respiratory tract as evidence of the virus has been detected in serum and stool, the significance of which remains unclear. Presence of the virus in respiratory secretions, serum and stool suggests that this virus may cause systemic illness. SUMMARY: HBoV is an emerging human parvovirus. The full spectrum of disease associated with HBoV remains to be defined.     

Coronavirus-associated pneumonia in previously healthy children

The extent to which coronaviruses are associated with lower respiratory tract disease in previously healthy children without underlying medical conditions is unknown. We investigated instances of radiographically confirmed lower respiratory tract disease among symptomatic children with coronavirus infection. Here, we document the clinical courses of 2 previously healthy children with coronavirus-associated pneumonia.     

儿童呼吸道病毒感染的流行病学特点

呼吸系统感染是儿童门诊就诊最为常见的病因，也是造成＜5岁儿童死亡的首要原因。病毒是儿童时期呼吸道感染最为常见的病原，需要引起儿科医师关注。该文讨论了常见呼吸道病毒的流行病学特征，着重介绍了呼吸道合胞病毒、流感病毒、鼻病毒和腺病毒等较为常见的呼吸道病毒的好发年龄、好发季节、流行区域等流行病学特点。同时，也简要介绍了副流感病毒、偏肺病毒和冠状病毒等近期新发现的病毒的流行病学特征，并回顾了病毒共感染的相关信息。     

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.     

新近发现的呼吸道病毒感染流行病学与临床研究进展

呼吸道感染是儿科常见病、多发病,病因复杂,其中病毒在儿童呼吸道感染中起重要作用.近年来新发现的呼吸道病毒包括人偏肺病毒、SARS冠状病毒、人冠状病毒NL63和HKU1、人博卡病毒以及人多瘤病毒,本文对其流行现状和临床研究进展作一介绍.