Impact of human metapneumovirus and human cytomegalovirus versus other respiratory viruses on the lower respiratory tract infections of lung transplant recipients

Viral respiratory tract infections in lung transplant recipients may be severe. During three consecutive winter-spring seasons, 49 symptomatic lung transplant recipients with suspected respiratory viral infection, and 26 asymptomatic patients were investigated for presence of respiratory viruses either in 56 nasopharyngeal aspirate or 72 bronchoalveolar lavage samples taken at different times after transplantation. On the whole, 1 asymptomatic (3.4%) and 28 symptomatic (57.1%) patients were positive for human metapneumovirus (hMPV, 4 patients), influenza virus A (3 patients), and B (2 patients), respiratory syncytial virus (2 patients), human coronavirus (2 patients), human parainfluenza virus (2 patients), rhinovirus (5 patients), while 4 patients were coinfected by 2 respiratory viruses, and 5 were infected sequentially by 2 or more respiratory viruses. In bronchoalveolar lavage samples, hMPV predominated by far over the other viruses, being responsible for 60% of positive specimens, whereas other viruses were present in nasopharyngeal aspirates at a comparable rate. RT-PCR (detecting 43 positive samples/128 examined) was largely superior to monoclonal antibodies (detecting 17 positive samples only). In addition, HCMV was detected in association with a respiratory virus in 4/18 HCMV-positive patients, and was found at a high concentration (>10(5) DNA copies/ml) in 3/16 (18.7%) patients with HCMV-positive bronchoalveolar lavage samples and pneumonia. Coinfections and sequential infections by HCMV and respiratory viruses were significantly more frequent in patients with acute rejection and steroid treatment. In conclusion: (i) about 50% of respiratory tract infections of lung transplant recipients were associated with one or more respiratory viruses; (ii) hMPV largely predominates in bronchoalveolar lavage of symptomatic lung transplant recipients, thus suggesting a causative role in lower respiratory tract infections; (iii) RT-PCR appears to be the method of choice for detection of respiratory viruses in lung transplant recipients, (iv) a high HCMV load in bronchoalveolar lavage is a risk factor for viral pneumonia, suggesting some measure of intervention for the control of viral infection.     

The association of rhinoviruses with lower respiratory tract disease in hospitalized patients

An analysis of 32 hospitalized infants and children from whom rhinoviruses were isolated in our diagnostic laboratories in 1982-83 suggests that these agents are associated with lower respiratory tract disease with focal findings in susceptible patients. In 23 cases, an acute lower respiratory disease was the cause for admission, while nine patients were cultured after new respiratory symptoms developed during hospitalization. Presenting signs and symptoms included cough (23), fever (19), rhinorrhea (19), respiratory distress (14), and decreased feeding (15). Seventeen of 25 chest x-rays showed new focal abnormalities. Twenty-five patients had a significant underlying disease including seven with malignancies, six with respiratory tract abnormalities, and four with congenital heart lesions. Six of the remaining seven patients were less than 2 1/2 months of age. In no cases were significant bacterial or fungal pathogens isolated; two did have concomitant viral isolates. Rhinoviruses in the appropriate clinical setting are associated with significant pulmonary disease.     

Detection of human cytomegalovirus in transbronchial biopsies from lung transplant recipients

The role of human cytomegalovirus (HCMV) in lung transplantation (LT) and drawbacks related to viral quantification in bronchoalveolar lavage (BAL) underline the potential usefulness of investigating other specimens. Thirty-three LT recipients were prospectively studied by HCMV quantitative real time PCR on matched transbronchial biopsy (TBB), BAL, and whole blood specimens. Overall, 27/33 patients turned out HCMV-positive in at least one specimen: 7.1 %, 37.1 %, and 13.5 % of TBB, BAL, and blood samples, respectively. No significant association between HCMV on all types of specimens and acute rejection, lymphocytic bronchiolitis, bronchiolitis obliterans and bronchiolitis obliterans syndrome was found. HCMV pneumonia was associated to HCMV detection on TBB (p = 0.003) and whole blood (p = 0.008), not on BAL (p = 0.47). The highest mean viral load was detected in TBB from cases with HCMV pneumonia in comparison to all other cases, suggesting the potential use of HCMV investigation in TBB for evaluating posttransplant complications.     

Respiratory syncytial virus and human rhinoviruses are the major causes of severe lower respiratory tract infections in Kuwait

Respiratory infections are very common in Kuwait, yet little is known about the cause of severe lower respiratory tract infections. This study was designed to investigate the viral cause of lower respiratory tract infections using sensitive molecular methods. PCR was applied to investigate 10 respiratory viruses in respiratory samples from 1,014 patients aged between 3 days to 76 years with acute lower respiratory tract infections. Of the 1,014 patients with lower respiratory tract infections, 288 (28.4%) had a viral infection. One hundred fifty‐five (53.8%) presented with bronchiolitis, 100 (43.7%) with pneumonia, and 33 (11.5%) with croup. One hundred six (36.8%) and 99 (34.4%) patients had evidence of respiratory syncytial virus and human rhinoviruses infections, respectively. Adenoviruses were detected in 44 (15.2%) patients, while influenza A virus in 21 (7.3%) patients. The majority of respiratory syncytial virus infections (84%) were among patients aged <1 year. Similarly, of the 99 patients infected by human rhinoviruses, 50 (50.5%) were also among this age group. In contrast, most of influenza A virus infections, 12 of 21 (57.1%), were among patients aged over 16 years. Parainfluenza virus‐2 and human coronaviruses were not detected in any of the patients' samples. Over the 3‐year period, most of the hospitalized patients were seen during the autumn and winter months from October through March. These data show that respiratory syncytial virus and human rhinoviruses may be the major causes of lower respiratory tract infections in children admitted to hospital in Kuwait. J. Med. Virol. 82:1462–1467, 2010. © 2010 Wiley‐Liss, Inc.     

Detection of human bocavirus in Japanese children with lower respiratory tract infections

Human bocavirus (HBoV), a newly cloned human virus of the genus Bocavirus, was detected by PCR from nasopharyngeal swab samples (8 of 318; 5.7%) collected from children with lower respiratory tract infections. HBoV may be one of the causative agents of lower respiratory tract infections in young children.     

The value of polymerase chain reaction for the diagnosis of viral respiratory tract infections in lung transplant recipients.

BACKGROUND: Respiratory viruses cause severe infections in lung transplant recipients, which require rapid and accurate diagnosis for appropriate management. OBJECTIVES: To evaluate the added benefit of a multiplex PCR for respiratory viruses (influenza [FLU] A and B, respiratory syncytial virus [RSV] A and B and parainfluenza virus [PIV] 1, 2, and 3) complementing rapid respiratory viral culture (RRV) and FLU-A antigen detection (EIA) in this transplant population. RESULTS: Over 6 months, 116 nasal washes and bronchoalveolar lavages, obtained from 72 lung transplant recipients with symptoms of upper or lower respiratory tract infections, were tested in real time by RRV and FLU-A EIA, and batched frozen by PCR. One or more methods recognized a respiratory virus in 31 (27%) specimens, including 15 FLU-A, nine RSV and seven PIV. PCR identified 26 of 31 positive samples demonstrating a sensitivity of 84%, higher than RRV (67%) or EIA (54%). PCR, RRV and EIA detected 60, 80 and 54%, respectively, FLU-A samples. PCR and RRV were equivalent for RSV-A, PIV-2 and 3, but PCR found a significantly higher number of RSV-B and PIV-1. CONCLUSIONS: These data indicate that routine use of PCR will enhance the number and speed with which viral respiratory tract infections are diagnosed in lung transplant recipients.     

Detection of parvovirus B19 in the lower respiratory tract

BackgroundHuman parvovirus B19 infection generally displays a self-limiting course followed by viral clearance; although, in some cases, persistent infection may occur. Few cases of severe pulmonary disease following primary infection in both immunocompetent and immunocompromised patients were reported.ObjectivesTo investigate the prevalence and clinical impact of parvovirus B19 in the lower respiratory tract.Study designThe prevalence of parvovirus B19-DNA was evaluated by Real-Time PCR in 264 bronchoalveolar lavages (BAL) from 189 adult patients over a full-year period and related to demographic characteristics, underlying pathologies, immune status, admission to intensive care unit, mortality within 28 days, and discharge diagnosis.ResultsParvovirus B19-DNA was detected in 7/189 (3.7%) patients, without significant association to demographic characteristics, immune status, transplant versus non-transplant status, admission to intensive care unit, presence of haematological conditions. In two lung transplant recipients surveillance specimens were positive to B19. Four of the remaining five patients presented respiratory insufficiency. A significant association to mortality was found, as 3/7 (42.9%) positive patients died within 28 days. No patient presented serological evidence of recent or acute infection and viremia.ConclusionsParvovirus B19 may be detected at low frequency in BAL specimens from patients with different pathological backgrounds. This finding could be due to chronic infection with virus persistence in the lower respiratory tract, also in the absence of symptoms unequivocally attributable to B19. The high rate of mortality warrants the need for further studies to evaluate the opportunity to consider parvovirus B19 in the diagnostic work-up of lower respiratory tract infections.     

Detection of human rhinovirus C in children with acute lower respiratory tract infections in South Korea

Recently, HRV-C was identified as a new species of HRV, but its spectrum of clinical disease is still not clear. The purpose of this study was to investigate the molecular epidemiology of HRVs in children with acute lower respiratory tract infections (LRTIs). A total of 54 HRV-positive samples that were negative for other respiratory viruses were sequenced. HRV-A was detected in 33, HRV-B in 4, and HRV-C in 17 of these samples. All HRV-C-positive patients showed favorable clinical outcomes. We confirmed the presence of HRV-C in children with LRTIs, but its association with clinical severity is not clear.     

Frequent detection of human rhinoviruses, paramyxoviruses, coronaviruses, and bocavirus during acute respiratory tract infections

Viruses are the major cause of pediatric acute respiratory tract infection (ARTI) and yet many suspected cases of infection remain uncharacterized. We employed 17 PCR assays and retrospectively screened 315 specimens selected by season from a predominantly pediatric hospital-based population. Before the Brisbane respiratory virus research study commenced, one or more predominantly viral pathogens had been detected in 15.2% (n = 48) of all specimens. The Brisbane study made an additional 206 viral detections, resulting in the identification of a microbe in 67.0% of specimens. After our study, the majority of microbes detected were RNA viruses (89.9%). Overall, human rhinoviruses (HRVs) were the most frequently identified target (n = 140) followed by human adenoviruses (HAdVs; n = 25), human metapneumovirus (HMPV; n = 18), human bocavirus (HBoV; n = 15), human respiratory syncytial virus (HRSV; n = 12), human coronaviruses (HCoVs; n = 11), and human herpesvirus-6 (n = 11). HRVs were the sole microbe detected in 37.8% (n = 31) of patients with suspected lower respiratory tract infection (LRTI). Genotyping of the HRV VP4/VP2 region resulted in a proposed subdivision of HRV type A into sublineages A1 and A2. Most of the genotyped HAdV strains were found to be type C. This study describes the high microbial burden imposed by HRVs, HMPV, HRSV, HCoVs, and the newly identified virus, HBoV on a predominantly paediatric hospital population with suspected acute respiratory tract infections and proposes a new formulation of viral targets for future diagnostic research studies.     

Rhinovirus and the lower respiratory tract

Human rhinoviruses (HRVs) are well-recognised causes of common colds and associated upper respiratory tract complications such as sinusitis and otitis media. This article reviews information linking HRV infection to illness in the lower respiratory tract. HRVs are capable of efficient replication in vitro at temperatures present in the tracheobronchial tree and have been shown to cause productive infection, elaboration of cytokines and chemokines, and up-regulation of cell surface markers in human bronchial epithelial cells. In situ hybridisation studies have proven that HRV infection occurs in the tracheobronchial tree following experimental infection. Clinical studies report that HRV infection is the second most frequently recognised agent associated with pneumonia and bronchiolitis in infants and young children and commonly causes exacerbations of pre-existing airways disease in those with asthma, chronic obstructive pulmonary disease or cystic fibrosis. HRV infection is associated with one-third to one-half of asthma exacerbations depending on age and is linked to asthma hospitalisations in both adults and children. Limited information implicates HRV infection as a cause of severe lower respiratory tract illness in older adults and in highly immunocompromised hosts, particularly bone marrow transplant recipients. More information is needed about the pathogenesis of HRV infection with regard to lower respiratory tract complications in these diverse patient groups. Given the large unmet medical need associated with HRV infections, safe and effective antiviral agents are needed for both prevention and treatment of these infections.     

肺癌患者下呼吸道病毒抗原检测

目的　了解肺癌患者下呼吸道病毒感染情况。方法　通过纤维支气管镜刷取肿物周围之分泌物,采用北京军区第262医院研制的呼吸道病毒抗原检测试剂盒进行检测、分析。结果　肺癌组呼吸道病毒抗原阳性8例,阳性率174%(846),显著高于非肺癌组(P<005)。其中甲型流感病毒1例,乙型流感病毒2例,副流感病毒(1,3型)2例,腺病毒2例,呼吸道合胞病毒1例。鳞癌、小细胞癌、腺癌伴病毒感染依次为4例、3例、1例。结论　肺癌与常见呼吸道病毒感染有统计学上的相关性,肺癌患者感染率增加,值得重视。     

鼻病毒在婴幼儿下呼吸道感染中作用的研究

目的探讨鼻病毒在婴幼儿下呼吸道感染中的作用。方法收集2008年5月到2009年4月北京儿童医院下呼吸道感染住院儿童鼻咽分泌物标本240份,使用Real-timeRT-PCR方法筛选鼻病毒阳性标本,并进行统计分析。结果在240例住院儿童中,入院诊断为肺炎的208例,占86．67％（208／240）,支气管炎21例（8．14％）,毛细支气管炎11例,无死亡病例,男女病例比例为1．93：1,且2009年2月采集标本数达到最多。采用Real-timeRT-PCR方法检测为鼻病毒阳性的标本71份,阳性率为29．58％（71／240）,且主要的临床诊断症状是肺炎。发病年龄以2岁以下婴幼儿为主,占81．69％（58／71）,其中以13～18月、324月年龄组发病率最高,发病率为33．33％。结论鼻病毒感染季节为春季和冬季,尤以2岁以下婴幼儿感染为主,主要症状表现为肺炎、支气管炎及毛细支气管炎等下呼吸道感染。鼻病毒流行具有季节性,且传染性强,传播速度快,应做好医院内防护措施,避免交叉感染。