Coronavirus infection and hospitalizations for acute respiratory illness in young children

There is only limited knowledge on the burden of disease due to both new (HCoV‐NL63 and HKU‐1) and previously discovered coronaviruses (OC43 and 229E) in children. Respiratory specimens and clinical data were prospectively collected in an active, population‐based surveillance study over a 2‐year period from children aged <5 years hospitalized with acute respiratory symptoms or fever. These samples were retrospectively tested by real‐time RT‐PCR for HCoV‐NL63, HKU1, OC43, and 229E. Human coronaviruses (HCoVs) were identified in 2.2% of study children <2 years of age. Rates of HCoV‐associated hospitalization per 10,000 were 10.2 (95% CI 4.3, 17.6), 4.2 (95% CI 1.9, 6.9), and 0 (95% CI 0, 3.7) in children aged <6 months, 6–23 months, and 24–59 months, respectively. Coronaviruses were identified in a modest number of hospitalized children. J. Med. Virol. 81:853–856, 2009. © 2009 Wiley‐Liss, Inc.     

呼吸道合胞病毒下呼吸道感染对机体细胞免疫的影响

为研究呼吸道合胞病毒（ＲＳＶ）急性下呼吸道感染（ＡＬＲＩ）的细胞免疫变化，对２５例病儿外周血白细胞介素２（ＩＬ－２）和可溶性白细胞介素２受体（ｓＩＬ－２Ｒ）水平、Ｔ细胞白细胞介素２受体（ＩＬ－２Ｒ）表达率和Ｔ细胞亚群百分率进行检测。结果显示，急性期病儿外周血ＩＬ－２水平明显低于恢复期和正常对照组，Ｔ细胞ＩＬ－２Ｒ表达率亦明显降低，而ｓＩＬ－２Ｒ水平却显著增高。急性期病儿ＩＬ－２水平与Ｔ细胞ＩＬ－２Ｒ表达率和ＣＤ＋４细胞百分率呈正相关，与ｓＩＬ－２Ｒ水平和ＣＤ＋８细胞百分率呈负相关；ｓＩＬ－２Ｒ水平与Ｔ细胞ＩＬ－２Ｒ表达率呈负相关，与临床严重程度呈正相关。上述各项免疫指标异常均提示ＲＳＶ感染时机体存在细胞免疫功能紊乱。     

Human bocavirus infection in young children with acute respiratory tract infection in Lanzhou,China

Human bocavirus (HBoV) is a recognized human parvovirus associated with acute respiratory tract infection. However, HBoV has yet to be established as a causative agent of respiratory disease. In this study, the epidemiological and virological characteristics of HBoV infection were studied in children with acute respiratory tract infection in China. In total, 406 children younger than 14 years of age with acute respiratory tract infection were included in this prospective 1‐year study. HBoV was detected in 29 (7.1%) of the 406 children. No clear seasonal fluctuation was observed in infection rates of HBoV. Of the 29 children infected with HBoV, 16 (55.2%) were coinfected with other respiratory viruses, most commonly respiratory syncytial virus (RSV). Viral coinfection with HBoV did not affect the severity of the respiratory disease (P = 0.291). The number of HBoV genome copies ranged from 5.80 × 10² to 9.72 × 10⁸ copies/ml in nasopharyngeal aspirates among HBoV‐positive specimens by real‐time PCR, and neither coinfection nor the severity of disease correlated with the viral load (P = 0.148, P = 0.354, respectively). The most common clinical features were cough and acute upper respiratory infection, and acute bronchopneumonia. Additionally, the NP‐1 gene of HBoV showed minimal sequence variation. These data suggest that HBoV is frequent in young children with acute respiratory tract infection in Lanzhou, China, and RSV is the most common coinfecting virus. There was no apparent association between the viral load of HBoV and coinfection or disease severity. The NP‐1 gene was highly conserved in HBoV. J. Med. Virol. 82:282–288, 2010. © 2009 Wiley‐Liss, Inc.     

Respiratory viruses in young South African children with acute lower respiratory infections and interactions with HIV

BackgroundHuman rhinovirus (RV) is the most common respiratory virus and has been associated with frequent and severe acute lower respiratory infections (ALRI). The prevalence of RV species among HIV-infected children in South Africa is unknown.ObjectivesTo describe the prevalence of respiratory viruses, including RV species, associated with HIV status and other clinical symptoms in children less than two years of age with and without ALRI in Pretoria, South Africa.Study designNasopharyngeal aspirates were collected from 105 hospitalized ALRI cases and 53 non-ALRI controls less than two years of age. HIV status was determined. Common respiratory viruses were identified by PCR, and RV species and genotypes were identified by semi-nested PCR, sequencing and phylogenetic tree analyses.ResultsRespiratory viruses were more common among ALRI cases than controls (83.8% vs. 69.2%; p = 0.041). RV was the most commonly identified virus in cases with pneumonia (45.6%) or bronchiolitis (52.1%), regardless of HIV status, as well as in controls (39.6%). RV-A was identified in 26.7% of cases and 15.1% of controls while RV-C was identified in 21.0% of cases and 18.9% of controls. HIV-infected children were more likely to be diagnosed with pneumonia than bronchiolitis (p < 0.01). RSV was not identified in any HIV-infected cases (n = 15) compared with 30.6% of HIV-uninfected cases (n = 85, p = 0.013), and was identified more frequently in bronchiolitis than in pneumonia cases (43.8% vs. 12.3%; p < 0.01).ConclusionsRV-A and RV-C are endemic in South African children and HIV infection may be protective against RSV and bronchiolitis.     

Correlation between bocavirus infection and humoral response,and co-infection with other respiratory viruses in children with acute respiratory infection

BackgroundHuman bocavirus (HBoV), a recently discovered virus, is prevalent among children with respiratory tract infection throughout the world. Co-infection was frequently found in HBoV-positive patients. Thus, whether HBoV is responsible for the respiratory disease is still arguable.ObjectivesA comprehensive study was carried out to integrate clinical and virological prevalence in HBoV-positive outpatient children, and to determine genetic and serologic characteristics of HBoV in Shanghai, China.Study designNasal/throat swabs and sera were obtained over a 2-year period from 817 children with respiratory tract infection to examine the presence of HBoV and its co-infection. The seroepidemiology of HBoV was studied by ELISA and Western blot against the capsid protein VP2-based fragment. Persistence of HBoV was also analyzed in 12 pairs of return-visit cases.ResultsHBoV was identified in 96 samples (11.8%). The co-infection rate with other respiratory viruses was 51%. IgM was detected in 55.7% of HBoV RT-PCR-positive patients, and in 72.7% of those who had high viral genome load. In addition, persistent viral DNA positivity was detected in 10 of 12 HBoV-positive cases tested, an average of 14 days later, and one child was still HBoV-positive after 31 days.ConclusionHBoV was found frequently in children with respiratory tract symptoms associated with other respiratory viruses, and persisted in the respiratory tract and in serum and urine. The presence of IgM was significantly more prevalent in viremic patients and those diagnosed with high load of HBoV DNA in nasal/throat swabs.     

Class specific antibody response to gonococcal infection.

An enzyme immunoassay was used to determine IgM, IgG, and IgA antibodies to gonococcal pili in 68 patients with uncomplicated gonorrhoea, 35 women with pelvic inflammatory disease, and in 115 normal controls. A clear difference in response rate in all three antibody classes between patients with gonorrhoea and healthy controls was evident. Among women with gonorrhoea, the magnitude of antibody response was higher than among men with gonorrhoea, especially in the IgM class. No major differences were found in the overall distribution of serological findings between women with uncomplicated gonorrhoea and those with gonococcal pelvic inflammatory disease. Among this last group, however, high IgM antibody levels in acute phase sera were significantly associated with the isolation of Neisseria gonorrhoeae in the upper genital tract.     

Comparative molecular analysis of Haemophilus influenzae isolates from young children with acute lower respiratory tract infections and meningitis in Hanoi, Vietnam

Thirty-seven Haemophilus influenzae strains from nasopharyngeal swabs (NP) and 44 H. influenzae strains from cerebrospinal fluid (CSF) were investigated. Of the 37 H. influenzae isolates from NP, the serotypes of 30 isolates were nontypeable, 4 were type b, 2 were type c, and 1 was type a, whereas all of the 44 isolates from CSF were type b. The MICs of 16 antibiotics for the H. influenzae isolates from NP and CSF were similar, and no beta-lactamase-negative ampicillin-resistant strain was found. Molecular typing by pulsed-field gel electrophoresis (PFGE) showed that the 37 H. influenzae strains from NP had 22 PFGE patterns, with none predominating, and the 44 H. influenzae strains from CSF had 9 PFGE patterns, with patterns alpha (22 isolates) and beta (12 isolates) predominating. Our results indicate that two predominant types of H. influenzae type b strains have the potential to spread among children with meningitis in Hanoi, Vietnam.     

Characterization of the antibody response to a Haemophilus influenzae type b conjugate vaccine in children with recurrent lower respiratory tract infection

Children with recurrent lower respiratory tract infection (RLRI) may respond poorly to polysaccharide antigens. To examine how such children respond to a polysaccharide coupled to a protein carrier, we immunized 15 children with RLRI aged 8–69 months and 15 carefully age-matched healthy controls once with a Haemophilus influenzae type b (Hib) conjugate vaccine. Total IgG subclasses, total antipolysaccharide Hib antibodies, and antipolysaccharide Hib antibodies of IgM, IgG, IgA, and IgG 1–4 specificity were determined by ELISA. There were no significant differences between the two groups in any single total IgG subclass, but total IgG measured as the sum of all four subclasses was significantly lower in the children with RLRI than in the controls ( P = 0.036). Before vaccination, the children with RLRI had significantly less IgG antipolysaccharide Hib antibody than the controls ( P = 0.005), whereas 1 month later they had significantly more IgM antibody (P = 0.038). No other significant differences were found between the groups before or after immunization with respect to antipolysaccharide Hib antibodies. Since naturally occurring IgG antibodies are thought to be aquired partly as a consequence of antigenic stimulation on mucosal surfaces, we hypothesize that the low level of specific IgG found before immunization, as well as the low total IgG in the children with RLRI, may reflect an impaired ability to prime through mucosal surfaces. This is supported by our finding of an increased IgM response to Hib conjugate vaccine in these children, since this isotype predominates in the primary immune response, i.e., in the absence of immunologic memory. In conclusion, children with RLRI can be protected against invasive Hib infection as well as healthy children, but may have an immunodeficiency characterized by defective ability to respond to antigenic stimulation on mucosal surfaces.     

急性呼吸道感染住院患儿RSV和ADV与病情严重程度相关性研究

目的 通过对呼吸道合胞病毒(RSV)及腺病毒(ADV)临床检测阳性率来评价儿童急性呼吸道感染病情严重程度的相关性分析.方法 将82例患急性呼吸道感染的儿童(感染组)及30例健康儿童(健康组)作为观察对象,比较两组RSV和ADV阳性率;同时根据感染严重程度,将感染组患儿分为28例的非肺炎组、33例的普通肺炎组及21例的重症肺炎组,对比三组间RSV和ADV阳性率.此外,对感染组患儿中RSV和ADV阳性率与感染严重程度、血常规白细胞计数(WBC)、中性粒细胞百分比(N％)及淋巴细胞百分比(L％)的相关性.结果 感染组RSV和ADV阳性率明显高于健康组(P ＜0.05),而不同严重程度感染组中,以重症肺炎组RSV和ADV阳性率最高(P＜0.05),同时感染组中,RSV和ADV阳性率与患者的感染严重程度存在显著的直线相关性,但与WBC、N％及L％无直线相关性.结论 RSV和ADV阳性率可作为评价急性呼吸道感染患儿病情严重程度的指标.     

Serum antibody response to proteins of Moraxella (Branhamella) catarrhalis in patients with lower respiratory tract infection.

We searched for antibodies against Moraxella (Branhamella) catarrhalis proteins in the sera of patients with lower respiratory tract infection. Sera from 48 patients with M. catarrhalis and 39 patients without M. catarrhalis in their lower respiratory tract specimens were studied by a gel electrophoresis-immunoperoxidase technique; sera from 23 healthy adult blood donors were also included. Immunoglobulin G (IgG) antibodies against a 28-kDa protein were found significantly more frequently in patients with M. catarrhalis in lower respiratory tract specimens (71%) than in patients without M. catarrhalis in lower respiratory tract specimens (28%) or healthy adult blood donors (22%). Seroconversion, from the acute to the convalescent stages, occurred in at least eight patients with M. catarrhalis and in one patient without detectable M. catarrhalis. IgG antibodies against other M. catarrhalis proteins were found in most sera, including those obtained from blood donors. By adsorption experiments the 28-kDa protein was demonstrated to be surface exposed. IgM antibodies against an 85-kDa protein were found in serum from one patient from whom M. catarrhalis and Streptococcus pneumoniae were isolated from the lower respiratory tract, while IgA antibodies against M. catarrhalis proteins could not be detected in any serum specimen.     

支气管肺发育不良患儿发生急性病毒性下呼吸道感染的预测因素分析

目的:探讨支气管肺发育不良(BPD)患儿发生急性病毒性下呼吸道感染(AVLRI)的预测因素分析。方法:回顾性调查2015 年6 月至2017 年6 月我院收治的BPD 合并AVLRI 患儿60 例作为合并组,同期选取60 例BPD 无合并AVLRI 患儿作为对照组,分析BPD 患儿发生AVLRI 的预测因素。结果:本次调查中,合并组以呼吸道合胞病毒(RSV)感染为主,有35 例(58.00%);单因素法分析结果显示,BPD 患儿发生AVLRI 与季节、喂养方式、家庭吸烟和患儿BPD 病情、出生体重、合并基础疾病、合并先心病及母体孕期糖尿病、特应性疾病等因素有关(P<0.05);Logistics 多因素法分析结果显示,秋冬季节、患儿重度BPD、合并先心病、母体特应性疾病、人工喂养是BPD 患儿发生AVLRI 的预测因素(P<0.05)。结论:BPD 合并AVLRI 患儿常因RSV 发病,其发生是由多种因素引起,秋冬季节、患儿重度BPD、合并先心病、母体特应性疾病、人工喂养等可能可作为其发生的预测因素,应针对上述因素采取各项有效的干预措施。     

呼吸道病毒特异性IgM检测对儿童呼吸道感染的指导意义

目的:统计分析急性呼吸道感染患儿5种常见呼吸道病毒特异性Ig M的检出情况用以指导临床。方法:2012年1月~12月我院儿科住院急性呼吸道感染患儿1 609例,收集血清采用间接免疫荧光方法检测呼吸道合胞病毒(RSV)、腺病毒(ADV)、甲型流感病毒(IVA)、乙型流感病毒(IVB)、副流感病毒(PIV)特异性Ig M。结果:1 609例患儿检出阳性标本263例(16.35%),IVB检出率最多,共136例(8.45%),其余依次为IVA 63例(3.92%)、PIV 62例(3.85%)、ADV 44例(2.73%)、RSV 42例(2.61%)。不同年龄组患儿阳性标本检出率不同,差异具有统计学意义(χ2=134.822,P0.01),随年龄增长阳性标本检出率逐渐增高,学龄期儿童检查率最高(34.55%);IVB、PIV、IVA阳性标本检出率在不同年龄阶段的比较差异具有统计学意义(χ2分别为102.660、86.145、39.791,均P0.05),IVB和IVA以学龄期儿童检查率为最高,分别达20.00%和8.64%,PIV以学龄前儿童检出率最高(12.07%)。不同呼吸道病毒Ig M阳性检出率在不同月份有各自的特点,IVB在3月和10月出现两个检出高峰,检出率分别达20.15%和11.11%;IVA在3月和5月出现两个检出高峰,检出率分别达10.27%和11.81%;PIV、RSV检出率在1~6月份平缓上升,在3月份检出率最高,分别达7.98%和6.46%,随后检出率又平稳下降;ADV在3、4、5三个月份检出率为最高,检出率达6.19%。结论:5种呼吸道病毒检出阳性率达16.35%,尤以IVB检出率为最高;呼吸道病毒特异性Ig M阳性检出率随年龄增长而逐渐增高,IVB和IVA以学龄期儿童感染率最高,而PIV以学龄前儿童感染率最高;5种呼吸道病毒感染在2012年有各自的流行特点。     

WU polyomavirus in children with acute lower respiratory tract infections, China.

BACKGROUND: WU polyomavirus (WUPyV), a new member of the genus of Polyomavirus in the family Polyomaviridae, has been found and associated with respiratory tract infections recently. However, its clinical role and pathogenicity has not been known. OBJECTIVES: To confirm that WU polyomavirus has been found in Chinese children. STUDY DESIGN: WU polyomavirus was detected and identified using PCR methods. A total of 278 specimens of nasopharyngeal aspirate were collected, and then PCR products were sequenced directly. RESULTS: One of 278 nasopharyngeal aspirates was positive for WUPyV in one child, and the positive rate was 0.4%. The results showed that the sequences of genome, LTAg and VP2 gene was identical to the reference sequences of WU polyomavirus prototype strains. CONCLUSIONS: We confirmed that WU polyomavirus had been found and identified in the respiratory secretions in China.     

Rotavirus infection of the oropharynx and respiratory tract in young children.

Oropharyngeal aspirates were obtained from 89 infants hospitalized with respiratory illnesses accompanied or not by diarrhea and 33 control patients without the diseases. Rotavirus was detected from 25 of these patients by immunocytology, isolation of the virus in cultures of MA104 cells, or both. None of the control patients gave a positive result. The infection involves squamous cells and globlet cells probably originating from the oropharynx, and ciliated columnar epithelial cells from the respiratory tract. The virus from 2 specimens was propagated by repeatedly passaging in the cultures and found to have characteristic morphology of rotavirus. The electrophoretic patterns of the viral RNA extracted from them are closely similar to those obtained with the rotavirus genome extracted from the stool of the same patients. Repeated stool specimens were also obtained, and sera were paired from some of these subjects. All but one of the patients who gave a positive virology for their aspirates also showed a significant rise in the titres of common group A rotavirus antibody, neutralizing antibody against one or more of serotypes of rotavirus, or both. Patients who excreted rotavirus in their stools were younger and had significantly lower titres of rotavirus antibodies in their acute sera, than those who shedded the virus in the oropharynx but did not excrete the virus in repeated stool specimens. The prevalence of rotavirus in the oropharyngeal aspirates from these patients surpassed that of adenovirus, respiratory syncytial virus, influenza virus, and herpes simplex virus combined.     

Local antibody production and respiratory syncytial virus infection in children with leukaemia

Children undergoing therapy for acute lymphoblastic leukaemia (ALL) are at increased risk of severe viral respiratory infection, and some find it difficult to terminate virus secretion. This increased severity may result from a defect in the mucosal immune response. To test this hypothesis, nasal immunoglobulin secretion and specific antiviral antibody responses to infection with respiratory syncytial (RS) virus in children with ALL have been compared with those in a normal age-matched comparison group. Children with leukaemia secreted normal levels of IgA and slightly raised IgM levels. IgG levels were depressed. Following RS virus infection, the majority of children with leukaemia secreted normal amounts of IgA and IgG nasal antibody and successfully cleared the virus. However, three of the 13 children studied made poor or undetectable nasal antibody responses, which correlated with their inability to clear the virus.     

Airway microbiota and acute respiratory infection in children

Acute respiratory infections (ARIs), such as bronchiolitis and pneumonia, are the leading cause of hospitalization of infants in the US. While the incidence and severity of ARI can vary widely among children, the reasons for these differences are not fully explained by traditional risk factors (e.g., prematurity, viral pathogens). The recent advent of molecular diagnostic techniques has revealed the presence of highly functional communities of microbes inhabiting the human body (i.e., microbiota) that appear to influence development of local and systemic immune response. We propose a ‘risk and resilience’ model in which airway microbiota are associated with an increased (risk microbiota) or decreased (resilience microbiota) incidence and severity of ARI in children. We also propose that modulating airway microbiota (e.g., from risk to resilience microbiota) during early childhood will optimize airway immunity and, thereby, decrease ARI incidence and severity in children.