Highly frequent infections with human rhinovirus in healthy young children: A longitudinal cohort study

AbstractBackgroundHuman rhinoviruses (HRVs) are an important cause of respiratory tract infections.ObjectivesWe questioned whether the high prevalence rates of HRVs found in epidemiological studies is due to long-term individual continuity or a result of frequent infections with different HRV subtypes.Study designIn a 6-month winter period 18 healthy controls, aged 0–7 years, were at least sampled every two weeks for HRV-PCR, irrespective of respiratory symptoms. All HRV positive samples were genotyped to determine HRV diversity.ResultsIn total 272 samples were collected. HRV was found in 101/272 (37%) samples. Genotyping revealed 27 different HRV subtypes. A median of 3.0 different HRV subtypes was found per child. Re-infections and continuity with identical HRV sequences were observed. The number of HRVs were higher in the youngest age group (p=0.01) and they had more different HRV subtypes (p=0.05) compared to oldest age group.ConclusionsWe found a high HRV exposition with a considerable diverse population of HRV subtypes in young children. These results have major implications for future research into the pathogenic role of HRV in respiratory diseases. Characterisation of subtypes will be necessary to discriminate between prolonged continuity and re-infections in patients with respiratory diseases

Human coronavirus 229E encodes a single ORF4 protein between the spike and the envelope genes

BACKGROUND: The genome of coronaviruses contains structural and non-structural genes, including several so-called accessory genes. All group 1b coronaviruses encode a single accessory protein between the spike and envelope genes, except for human coronavirus (HCoV) 229E. The prototype virus has a split gene, encoding the putative ORF4a and ORF4b proteins. To determine whether primary HCoV-229E isolates exhibit this unusual genome organization, we analyzed the ORF4a/b region of five current clinical isolates from The Netherlands and three early isolates collected at the Common Cold Unit (CCU) in Salisbury, UK. RESULTS: All Dutch isolates were identical in the ORF4a/b region at amino acid level. All CCU isolates are only 98% identical to the Dutch isolates at the nucleotide level, but more closely related to the prototype HCoV-229E (>98%). Remarkably, our analyses revealed that the laboratory adapted, prototype HCoV-229E has a 2-nucleotide deletion in the ORF4a/b region, whereas all clinical isolates carry a single ORF, 660 nt in size, encoding a single protein of 219 amino acids, which is a homologue of the ORF3 proteins encoded by HCoV-NL63 and PEDV. CONCLUSION: Thus, the genome organization of the group 1b coronaviruses HCoV-NL63, PEDV and HCoV-229E is identical. It is possible that extensive culturing of the HCoV-229E laboratory strain resulted in truncation of ORF4. This may indicate that the protein is not essential in cell culture, but the highly conserved amino acid sequence of the ORF4 protein among clinical isolates suggests that the protein plays an important role in vivo

Prevalence and Pathogenicity of WU and KI Polyomaviruses in Children, the Netherlands

A longitudinal study in 2004 and 2005 detected polyomaviruses WU and KI in 44% and 17% of children with and without respiratory symptoms, respectively, in the Netherlands. In some children both viruses were detected for long periods. In several symptomatic children no other respiratory pathogen was detected

Risk factors for acute respiratory tract infections in general practitioner patients in The Netherlands: a case-control study

<p>Abstract</p> <p>Background</p> <p>Acute respiratory tract infections (ARTI) are an important public health problem. Improved identification of risk factors might enable targeted intervention. Therefore we carried out a case-control study with the aim of identifying environmental risk factors for ARTI consultations in the Dutch general population.</p> <p>Methods</p> <p>A subset of patients visiting their GP in the period of 2000–2003 with an ARTI (cases) and age-matched controls (visiting for other complaints) were included in a case-control study. They were asked to complete a questionnaire about potential risk factors. Conditional logistic regression was used to calculate odds ratio's (OR) and 95% confidence intervals (CI) to estimate the independent effect of potential risk factors.</p> <p>Results</p> <p>A total of 493 matched pairs of case and control subjects were enrolled. Exposure to persons with respiratory complaints, both inside and outside the household, was found to be an independent risk factor for visiting a GP with an ARTI (respectively OR_adj= 1.9 and OR_adj= 3.7). Participants exposed to dampness or mould at home (OR_adj=0.5) were significantly less likely to visit their GP. In accordance with the general risk of consultations for ARTI, participants with a laboratory-confirmed ARTI who were exposed to persons with respiratory complaints outside the household were also significantly more likely to visit their GP (OR_adj=2.5).</p> <p>Conclusion</p> <p>This study confirmed that heterogeneity in the general population as well as in pathogens causing ARTI makes it complicated to detect associations between potential risk factors and respiratory infections. Whereas it may be difficult to intervene on the risk posed by exposure to persons with respiratory complaints, transmission of ARTI in the general population might be reduced by improved hygienic conditions.</p

Frequency and Duration of Rhinovirus Infections in Children with Cystic Fibrosis and Healthy Controls : A Longitudinal Cohort Study

BACKGROUND: Respiratory viral infections are an important cause of morbidity in patients with chronic respiratory diseases, such as cystic fibrosis (CF). We hypothesized that patients with CF are more susceptible to human rhinovirus (HRV) infections than healthy controls. METHODS: In a 6-months winter period 20 young children with CF (0-7 years) and 18 age-matched healthy controls were sampled bi-weekly for HRV-PCR using nasopharyngeal swabs, irrespective of respiratory symptoms. Respiratory symptoms were scored twice a week. If any symptom was present an additional sample was obtained. All HRV positive samples were genotyped to distinguish HRV subtypes. RESULTS: We analyzed 645 samples, with comparable total numbers of samples in both groups. HRV was detected in 40.8% of all analyzed samples. Children with CF had significantly more HRV positive samples compared to healthy controls, with a mean number (± SD) of 8.1 ± 2.3 versus 5,7 ± 2.9 positive samples per individual (p2 weeks) with the same HRV subtype occurred more frequently in the CF patients (p<0.01). The genetic distribution and pattern of phylogenetic diversity of the different HRV subtypes was similar in both groups. CONCLUSION: This is the first in vivo longitudinal study showing that HRV is detected more frequently and persists for longer periods in CF patients compared to healthy controls. This might indicate increased viral replication and/or decreased anti-viral defense in patients with CF

Rhinovirus wheezing illness in infancy is associated with medically attended third year wheezing in low risk infants : results of a healthy birth cohort study

Rhinoviruses may be pathogens contributing to the development of childhood wheezing. However, their role in low risk infants without an asthmatic predisposition is unknown. Knowing which healthy, low risk children are at increased risk for childhood wheezing after rhinovirus wheezing illness (RV-WI) in infancy, might help in developing prevention and treatment strategies for childhood wheezing. The aim of this study was to determine the association of medically attended wheezing at the age of three with RV-WI in the first year of life in low risk children without parental asthma. In a low risk, prospective birth cohort study, we followed 181 healthy born children from birth through the third year of life. We considered children 'low risk' if neither parent had a doctor's diagnosis of asthma. We determined infant RV-WI by parent-reported wheezing (based on daily logs) and simultaneous molecular rhinovirus detection in the first year of life. Respiratory function and blood eosinophil count were both measured in the first month of life. The primary outcome, third year wheezing, was defined as the use of prescribed inhaled asthma medications together with a doctor's visit for respiratory symptoms in the third year of life. We calculated the association of RV-WI with medically attended third year wheezing and other known possible risk factors for wheezing at the age of three. Among low risk children, third year wheezing was observed in 7 out of 18 (39%) children with versus 10 out of 163 (6%) children without infant RV-WI (OR 9.7, 95% CI 3.1-33.5, P < 0.0001). The association between RV-WI and third year wheezing was unchanged after adjustment for potential confounders such as eosinophilia and atopic eczema. RV-WI is a robust and independent risk factor for third year wheezing in low risk children without parental asthma. Future research will identify and protect those children at increased risk for RV-WI

Frequency and Duration of Rhinovirus Infections in Children with Cystic Fibrosis and Healthy Controls : A Longitudinal Cohort Study

BACKGROUND: Respiratory viral infections are an important cause of morbidity in patients with chronic respiratory diseases, such as cystic fibrosis (CF). We hypothesized that patients with CF are more susceptible to human rhinovirus (HRV) infections than healthy controls. METHODS: In a 6-months winter period 20 young children with CF (0-7 years) and 18 age-matched healthy controls were sampled bi-weekly for HRV-PCR using nasopharyngeal swabs, irrespective of respiratory symptoms. Respiratory symptoms were scored twice a week. If any symptom was present an additional sample was obtained. All HRV positive samples were genotyped to distinguish HRV subtypes. RESULTS: We analyzed 645 samples, with comparable total numbers of samples in both groups. HRV was detected in 40.8% of all analyzed samples. Children with CF had significantly more HRV positive samples compared to healthy controls, with a mean number (± SD) of 8.1 ± 2.3 versus 5,7 ± 2.9 positive samples per individual (p2 weeks) with the same HRV subtype occurred more frequently in the CF patients (p<0.01). The genetic distribution and pattern of phylogenetic diversity of the different HRV subtypes was similar in both groups. CONCLUSION: This is the first in vivo longitudinal study showing that HRV is detected more frequently and persists for longer periods in CF patients compared to healthy controls. This might indicate increased viral replication and/or decreased anti-viral defense in patients with CF