HRV Infections Research Articles

Disease Burden and Inpatient Management of Children with Acute Respiratory Viral Infections during the Pre-COVID Era in Germany: A Cost-of-Illness Study.

Respiratory viral infections (RVIs) are common reasons for healthcare consultations. The inpatient management of RVIs consumes significant resources. From 2009 to 2014, we assessed the costs of RVI management in 4776 hospitalized children aged 0-18 years participating in a quality improvement program, where all ILI patients underwent virologic testing at the National Reference Centre followed by detailed recording of their clinical course. The direct (medical or non-medical) and indirect costs of inpatient management outside the ICU ('non-ICU') versus management requiring ICU care ('ICU') added up to EUR 2767.14 (non-ICU) vs. EUR 29,941.71 (ICU) for influenza, EUR 2713.14 (non-ICU) vs. EUR 16,951.06 (ICU) for RSV infections, and EUR 2767.33 (non-ICU) vs. EUR 14,394.02 (ICU) for human rhinovirus (hRV) infections, respectively. Non-ICU inpatient costs were similar for all eight RVIs studied: influenza, RSV, hRV, adenovirus (hAdV), metapneumovirus (hMPV), parainfluenza virus (hPIV), bocavirus (hBoV), and seasonal coronavirus (hCoV) infections. ICU costs for influenza, however, exceeded all other RVIs. At the time of the study, influenza was the only RVI with antiviral treatment options available for children, but only 9.8% of influenza patients (non-ICU) and 1.5% of ICU patients with influenza received antivirals; only 2.9% were vaccinated. Future studies should investigate the economic impact of treatment and prevention of influenza, COVID-19, and RSV post vaccine introduction.

Specific Assay of Negative Strand Template to Quantify Intracellular Levels of Rhinovirus Double-Stranded RNA.

Human rhinovirus infections are a major trigger for acute exacerbations of lower airway diseases, including asthma and chronic obstructive pulmonary disease. Disease exacerbation is thought to be regulated via double-stranded RNA (dsRNA)-mediated signaling of proinflammatory and host defense responses in airway epithelial cells. Despite the central role of dsRNA in regulating host cell responses, no method for the quantitative assessment of dsRNA levels during HRV infections has been developed. Conventional RT-PCR for the negative strand template is not effective as self-priming results in apparent signals, even in the absence of primer during reverse transcription. To avoid these issues, we developed a selective assay for the negative strand template that uses a chimeric primer containing a 5′ non-viral sequence for reverse transcription and a primer using the non-viral sequence during subsequent PCR. We established that this assay avoided issues of self-priming and is strand specific, as it is unaffected even in the presence of a 1000-fold excess of positive strand. Assays in primary human airway epithelial cells showed that negative strand was detectable within 6 h of virus exposure and peaked at 18 h after virus exposure. The temporal pattern of negative strand induction mirrored that of genomic RNA but was always 1000-fold lower than positive strand, indicating that the negative strand levels regulate levels of dsRNA formation. This assay will permit relative quantification of dsRNA during studies of HRV regulation of epithelial cell function.

Molecular and clinical characteristics related to rhinovirus infection in Brasília, Brazil.

IntroductionHuman rhinovirus (HRV) is one of the most common human viral pathogens related to infections of the upper and lower respiratory tract, which can result in bronchiolitis and pneumonia. However, the relevance of HRV in human health was under-estimated for long time due to the absence of molecular targets for influenza and influenza-like syndrome surveillance in Brasília, Brazil. ObjectivesThe main objective of this study was analyze the clinical characteristics and outcomes of HRV infections in comparison with patients without HRV and other common respiratory viruses.Materials and MethodsFor this purpose, new specific primer sets were designed based on the high throughput sequencing analysis in previous study. These primers were used for HRV detection by RT-qPCR and Sanger sequencing of amplified cDNA of 5′ genomic region. The phylogenetic tree with representative HRV isolates was constructed using the Mega X software. Statistical analysis considering the patient profiles were performed using IBM SPSS program with non-parametric tests.ResultsThe most prevalent virus in negative samples was rhinovirus (n = 40), including three rhinovirus species (rhinovirus A, B, and C). The odds ratio associated with HRV infection was 2.160 for patients younger than 2 years and 4.367 for people living in rural areas. The multiple analysis showed lower chance of patients with HRV presenting respiratory distress.ConclusionIn this study, it was reported the predominance of rhinoviruses in cases of respiratory illness for negative patients for the influenza and influenza-like syndrome surveillance, being rhinorrhea, the most significant symptom associated with the disease.Supplementary InformationThe online version contains supplementary material available at 10.1007/s42770-020-00411-0.

Indoleamine 2,3-Dioxygenase in Hematopoietic Stem Cell-Derived Cells Suppresses Rhinovirus-Induced Neutrophilic Airway Inflammation by Regulating Th1- and Th17-Type Responses

Asthma exacerbations are a major cause of intractable morbidity, increases in health care costs, and a greater progressive loss of lung function. Asthma exacerbations are most commonly triggered by respiratory viral infections, particularly with human rhinovirus (hRV). Respiratory viral infections are believed to affect the expression of indoleamine 2,3-dioxygenase (IDO), a limiting enzyme in tryptophan catabolism, which is presumed to alter asthmatic airway inflammation. Here, we explored the detailed role of IDO in the progression of asthma exacerbations using a mouse model for asthma exacerbation caused by hRV infection. Our results reveal that IDO is required to prevent neutrophilic inflammation in the course of asthma exacerbation caused by an hRV infection, as corroborated by markedly enhanced Th17- and Th1-type neutrophilia in the airways of IDO-deficient mice. This neutrophilia was closely associated with disrupted expression of tight junctions and enhanced expression of inflammasome-related molecules and mucin-inducing genes. In addition, IDO ablation enhanced allergen-specific Th17- and Th1-biased CD4+ T-cell responses following hRV infection. The role of IDO in attenuating Th17- and Th1-type neutrophilic airway inflammation became more apparent in chronic asthma exacerbations after repeated allergen exposures and hRV infections. Furthermore, IDO enzymatic induction in leukocytes derived from the hematopoietic stem cell (HSC) lineage appeared to play a dominant role in attenuating Th17- and Th1-type neutrophilic inflammation in the airway following hRV infection. Therefore, IDO activity in HSC-derived leukocytes is required to regulate Th17- and Th1-type neutrophilic inflammation in the airway during asthma exacerbations caused by hRV infections.

Epidemiology and persistence of rhinovirus in pediatric lung transplantation.

Infection with rhinovirus (HRV) occurs following pediatric lung transplantation. Prospective studies documenting frequencies, persistence, and progression of HRV in this at-risk population are lacking. In the Clinical Trials in Organ Transplant in Children prospective observational study, we followed 61 lung transplant recipients for 2years. We quantified molecular subtypes of HRV in serially collected nasopharyngeal (NP) and bronchoalveolar lavage (BAL) samples and correlated them with clinical characteristics. We identified 135 community-acquired respiratory infections (CARV) from 397 BAL and 480 NP samples. We detected 93 HRV events in 42 (68.8%) patients, 22 of which (23.4%) were symptomatic. HRV events were contiguous with different genotypes identified in 23 cases, but symptoms were not preferentially associated with any particular species. Nine (9.7%) HRV events persisted over multiple successive samples for a median of 36days (range 18-408days). Three persistent HRV were symptomatic. When we serially measured forced expiratory volume in one second (FEV1) in 23 subjects with events, we did not observe significant decreases in lung function over 12months post-HRV. In conjunction with our previous reports, our prospectively collected data indicate that molecularly heterogeneous HRV infections occur commonly following pediatric lung transplantation, but these infections do not negatively impact clinical outcomes.

Epidemiological characteristics and clinical outcomes of human rhinovirus infections in a hospitalized population. Severity is independently linked to RSV coinfection and comorbidities

Human rhinovirus (hRV) is a predominant respiratory viral pathogen. The determinants that lead to adverse clinical outcomes in hospitalized patients are unclear.Our objective was to analyze the epidemiological and clinical characteristics of hRV infections in a hospitalized population and to compare non-severe and severe infections.The study was based on data from all patients with a respiratory episode admitted to Hospital from October 2015 to September 2016.During the study period, out of 2465 respiratory episodes, 434 were detected positive for hRV. Most of the coinfections involved the respiratory syncytial virus (RSV) and very few influenza viruses. A possible interference between rhinovirus and influenza virus is suggested.Airway involvement was present in a large part of hRV infections with 28.4 % (n = 48/169) of bronchiolitis and 3.6 % (n = 6/169) of bronchitis. One third of patients had at least one of the following severity criteria: need for oxygen therapy, hospitalization ≥ 5 days, and admission to the ICU. On multivariate analysis, a respiratory co-infection with RSV and the presence of a chronic respiratory disease (including a history of asthma) were shown to be independent risk factors for the onset of a severe infection in patients ≤ 2 years old. In a case control study based on 70 patients, hRV-A was the predominant lineage, followed closely by hRV-C. High viral load or viral genotypes were not associated with severe infection.

Typical epidemiology of respiratory virus infections in a Brazilian slum.

Host population size, density, immune status, age structure, and contact rates are critical elements of virus epidemiology. Slum populations stand out from other settings and may present differences in the epidemiology of acute viral infections. We collected nasopharyngeal specimens from 282 children aged ≤5 years with acute respiratory tract infection (ARI) during 2005 to 2006 in one of the largest Brazilian slums. We conducted real‐time reverse transcription‐polymerase chain reaction (RT‐PCR) for 16 respiratory viruses, nested RT‐PCR‐based typing of rhinoviruses (HRVs), and collected clinical symptoms. Viruses were common causes of respiratory disease; with ≥1 virus being detected in 65.2% of patients. We detected 15 different viruses during 1 year with a predominance of HRV (33.0%) and human respiratory syncytial virus (hRSV, 12.1%) infections, and a high rate of viral coinfections (28.3%). We observed seasonality of hRSV, HRV and human coronavirus infections, more severe symptoms in hRSV and influenza virus (FLU) infections and prolonged circulation of seven HRV clusters likely representing distinct serotypes according to genomic sequence distances. Potentially unusual findings included the absence of human metapneumovirus detections and lack of typical FLU seasonal patterns, which may be linked to the population size and density of the slum. Nonetheless, most epidemiological patterns were similar to other studies globally, suggesting surprising similarities of virus‐associated ARI across highly diverse settings and a complex impact of population characteristics on respiratory virus epidemiology.

Rhinovirus replication and innate immunity in highly differentiated human airway epithelial cells

BackgroundHuman rhinovirus (HRV) infections are the primary cause of the common cold and are a major trigger for exacerbations of lower airway diseases, such as asthma and chronic obstructive pulmonary diseases. Although human bronchial epithelial cells (HBE) are the natural host for HRV infections, much of our understanding of how HRV replicates and induces host antiviral responses is based on studies using non-airway cell lines (e.g. HeLa cells). The current study examines the replication cycle of HRV, and host cell responses, in highly differentiated cultures of HBE.MethodsHighly differentiated cultures of HBE were exposed to initial infectious doses ranging from 104 to 101 50% tissue culture-infective dose (TCID50) of purified HRV-16, and responses were monitored up to 144 h after infection. Viral genomic RNA and negative strand RNA template levels were monitored, along with levels of type I and II interferons and selected antivirals.ResultsRegardless of initial infectious dose, relatively constant levels of both genomic and negative strand RNA are generated during replication, with negative strand copy numbers being10,000-fold lower than those of genomic strands. Infections were limited to a small percentage of ciliated cells and did not result in any overt signs of epithelial death. Importantly, regardless of infectious dose, HRV-16 infections were cleared by HBE in the absence of immune cells. Levels of type I and type III interferons (IFNs) varied with initial infectious dose, implying that factors other than levels of double-stranded RNA regulate IFN induction, but the time-course of HRV-16 clearance HBE was the same regardless of levels of IFNs produced. Patterns of antiviral viperin and ISG15 expression suggest they may be generated in an IFN-independent manner during HRV-16 infections.ConclusionsThese data challenge a number of aspects of dogma generated from studies in HeLa cells and emphasize the importance of appropriate cell context when studying HRV infections.

Rhinovirus infections in infants suggest that early detection can prevent unnecessary treatment

BackgroundHuman rhinoviruses (hRV) are small, RNA viruses of the Picornaviridae family, which are divided into three subtypes (A, B, C). hRVs are among the most common causes for acute respiratory illnesses (ARI) involving both the upper and lower respiratory tract. ObjectivesThis study aimed to assess the magnitude and characteristics of hRV infections in hospitalized children, aged less than 5 years, hospitalized in Israel during 2011-2012. Study designThe 2503 respiratory samples were subjected to real-time PCR, to detect hRV and other respiratory viruses. Rhinovirus-positive samples were further tested by sequencing to identify the infecting species. ResultsOf these 2503 respiratory samples, 422 tested positive for hRV, of them, 243 were from children under 5 years of age (58% of all rhinoviral-positive samples). We also found that among the ARI-associated hospital admissions, 16% were positive for rhinovirus. hRV type A was the most common species. Laboratory data showed monocytosis in 51%, hypercalcemia in 61% and lower respiratory tract involvement in 75% of patients. ConclusionsWe thus recommend including rhinovirus testing as part of the routine testing performed in young children presenting with ARI.

Interleukin-13 associates with life-threatening rhinovirus infections in infants and young children.

Delineate risk factors associated with severe hypoxemia (O2 sat ≤87%) in infants and children younger than 2 years hospitalized with single pathogen HRV infection. Prospective study in a yearly catchment population of 56 560 children <2 years old between 2011 and 2013 in Argentina. All children with respiratory signs and O2 sat <93% on admission were included. HRV infections were identified by reverse transcriptase-polymerase chain reaction. Epidemiologic, clinical, viral, and immunological risk factors were assessed. Among 5012 hospitalized patients, HRV was detected as a single pathogen in 347 (6.92%) subjects. Thirty-two (9.2%) had life-threatening disease. Traditional risk factors for severe bronchiolitis did not affect severity of illness. HRV viral load, HRV groups, and type II and III interferons did not associate with severe hypoxemia. Interleukin-13 Levels in respiratory secretions at the time of admission (OR = 7.43 (3-18.4); P < 0.001 for IL-13 >10 pg/mL) predisposed to life-threatening disease. Targeted interventions against IL-13 should be evaluated to decrease severity of HRV illness in infancy and early childhood.

Phenotypical characterization of human rhinovirus infections in severely premature children

BackgroundHuman Rhinovirus (HRV) has been identified as the most common cause of acute respiratory infections and hospitalizations in premature children. It is unclear if premature children are more susceptible to HRV due to their decreased pulmonary reserve or because they have enhanced lower airway reactivity to HRV.MethodsWe conducted a retrospective analysis of the clinical respiratory presentation of all PCR-confirmed HRV infections in full-term and premature children aged ≤3 years in our institution. Standardized respiratory distress scores were developed to examine lower airway obstruction (i.e., wheezing, hyperinflation, and sub-costal retractions) along with markers of decreased pulmonary reserve (hypoxemia and tachypnea) in young children with HRV infections. Demographic and clinical variables were obtained from reviewing electronic medical records (EMR).ResultsThis study included a total of 205 children; 71% of these children were born full-term (>37 weeks gestation), 10% preterm (32–37 weeks) and 19% severely premature (<32 weeks). Our results demonstrated that: 1) HRV infections in the first 3 years of life were associated with higher overall respiratory distress scores in severely premature children relative to children born preterm or full-term; 2) HRV-infected severely premature children ≤3 years old were more likely to have lower airway obstruction than HRV-infected children born preterm or full-term; and 3) other clinical signs of respiratory distress such as tachypnea and hypoxemia were not more common in severely premature than in preterm and full-term children during an HRV infection.ConclusionsOur results indicate that HRV infections in severely premature children are associated with lower airway obstruction rather than hypoxemia or tachypnea. The latter suggests that enhanced airway reactivity is the underlying mechanism for the increased susceptibility to HRV in severely premature children. Longitudinal studies are needed to understand why premature babies develop airway hyper-reactivity to HRV and the long-term effects of early HRV infection in this population.

Biomarkers for Idiopathic Pneumonia Syndrome after Hematopoietic Cell Transplantation: Comparison with Viral Infectious Pneumonia

Background: Idiopathic pneumonia syndrome (IPS) is a non-infectious pulmonary complication with diffuse lung injury that develops in 5-10% of patients who undergo hematopoietic cell transplantation (HCT) and the mortality rate remains high at 50-90%. IPS is difficult to distinguish from occult pneumonia after HCT, because it is hard to exclude all infectious etiologies. There are currently no laboratory tests to aid physicians in the early detection of IPS and other pulmonary infections. The aim of this study was to identify prognostic biomarkers of future occurrence of IPS and compare their profiles to that for subjects with infectious pneumonia.Patients and methods: Among patients transplanted between 1988 and 2014 at FHCRC, we identified 42 patients with IPS based on radiographic findings and exclusion of possible pathogens using frozen bronchoalveolar lavage (BAL) samples of occult viral infections as recently reported (Blood 2015: 24: 3789-97). HCT recipients who did not require bronchoscopic examination and who did not grow any bacterial or fungal blood cultures within 100 days after HCT were considered as controls (n=163) and samples were collected at similar timepoints as IPS cases. We examined cases of viral pneumonia confirmed by positive BAL: human rhinovirus (HRV, n=18) and parainfluenza (PIV, n=21). A set of 1129 plasma samples from pre-HCT, day 7, day 14, day 21 post-HCT and at onset of each event was analyzed. The "onset sample" for controls was the sample closest to day 24 (median day of onset for patients with pulmonary symptoms). We measured six proteins by ELISA: Suppressor of tumorigenicity 2 (ST2), tumor necrosis factor receptor 1 (TNFR1), interleukin-6 (IL-6), lymphocyte vessel endothelial receptor (LYVE)-1, endothelial protein C receptor (EPCR), and herpes virus entry mediator (HVEM). TNFR1, LYVE-1, EPCR and HVEM were discovered through a proteomics approach, and ST2 and IL-6 were also measured due to their associations with endothelial processes and IPS (Blood 2015: 15: 2435-44), respectively.Multivariable logistic regression was used to evaluate the association of each protein with IPS vs. controls and IPS vs. HRV+PIV. Protein concentrations were log10 transformed and values below the lower limit of detection were replaced with that value (this occurred in 28% of the IL-6 measurements only). All analyses were adjusted for age, sex, transplant year, and acute GVHD status (grade 0-1 vs 2-4). Odds ratios indicate an increase in the odds of IPS for a tenfold increase in the protein concentration (Table 1). Receiver Operating Characteristic (ROC) curves were generated for each marker and if the area under the ROC (AUC) was greater than 0.7, then the analyte was considered an informative predictor of IPS.Results: Patients' characteristics are detailed in Table 1. Of the six proteins, TNFR1, ST2, LYVE-1, HVEM, and IL-6 were significantly elevated at the onset of IPS compared to controls at similar time point (adjusted, Table 2). ST2 and IL-6 were also elevated in infectious cases, although to a lesser degree. However, the biomarkers were able to distinguish IPS cases from viral infections (HRV and PIV) occurring approximately at the same time post HCT (Figure 1A). We also evaluated the prognostic value of the proteins by analyzing samples measured at day 7 post-HCT. All six proteins were elevated in IPS cases versus controls as early as day 7 with AUC from 0.85 to 0.75 (data not shown), and distinguished IPS from HRV and PIV infections (Figure 1B).Conclusion: Five proteins, TNFR1, ST2, LYVE-, HVEM, and IL-6 were significantly elevated at the onset of respiratory failure in IPS patients as compared to patients without pulmonary injury. Although the markers were also elevated in viral pulmonary infections, they were able to distinguish IPS from HRV and PIV. Importantly, these markers were elevated as early as day 7 after HCT, prior to the clinical signs of IPS. Additional analyses combining proteins together to form a composite panel are currently ongoing. [Display omitted] [Display omitted] [Display omitted] DisclosuresPaczesny:Viracor laboratories: Patents & Royalties: "Methods of detection of graft-versus-host disease" (US- 13/573,766).

Absence of back to school peaks in human rhinovirus detections and respiratory symptoms in a cohort of children with asthma.

Much of what is known about the seasonality of human rhinovirus (hRV) infections has been learned from the study of acute asthma exacerbations presenting to emergency care, including those among children at the start of the school term. Much less is known about the patterns of hRVs in the community. In this study, viruses and day-to-day symptoms of asthma and colds were monitored twice weekly in 67 children with asthma aged 5-12 years, over a 15 month period in Sydney, Australia. Overall hRV was detected in 314/1232 (25.5%) of nasal wash samples and 142/1231 (11.5%) of exhaled breath samples; of these, 231 and 24 respectively were genotyped. HRVs were detected with similar prevalence rate throughout the year, including no peak in hRV prevalence following return to school. No peaks were seen in asthma and cold symptoms using twice-weekly diary records. However, over the same period in the community, there were peaks in asthma emergency visits both at a large local hospital and in state-wide hospitalizations, following both return to school (February) and in late autumn (May) in children of the same age. This study suggests that hRV infections are common throughout the year among children, and differences in virus prevalence alone may not account for peaks in asthma symptoms.

Clinical and molecular epidemiology of human rhinovirus infections in patients with hematologic malignancy

BackgroundHuman rhinoviruses (HRVs) are common causes of upper respiratory tract infection (URTI) in hematologic malignancy (HM) patients. Predictors of lower respiratory tract infection (LRTI) including the impact of HRV species and types are poorly understood. ObjectivesThis study aims to describe the clinical and molecular epidemiology of HRV infections among HM patients. Study designFrom April 2012–March 2013, HRV-positive respiratory specimens from symptomatic HM patients were molecularly characterized by analysis of partial viral protein 1 (VP1) or VP4 gene sequence. HRV LRTI risk-factors and outcomes were analyzed using multivariable logistic regression. ResultsOne hundred and ten HM patients presented with HRV URTI (n=78) and HRV LRTI (n=32). Hypoalbuminemia (OR 3.0; 95% CI, 1.0–9.2; p=0.05) was independently associated with LRTI, but other clinical and laboratory markers of host immunity did not differ between patients with URTI versus LRTI. Detection of bacterial co-pathogens was common in LRTI cases (25%). Among 92 typeable respiratory specimens, there were 58 (64%) HRV-As, 12 (13%) HRV-Bs, and 21 (23%) HRV-Cs, and one Enterovirus 68. LRTI rates among HRV-A (29%), HRV-B (17%), and HRV-C (29%) were similar. HRV-A infections occurred year-round while HRV-B and HRV-C infections clustered in the late fall and winter. ConclusionsHRVs are associated with LRTI in HM patients. Illness severity is not attributable to specific HRV species or types. The frequent detection of bacterial co-pathogens in HRV LRTIs further substantiates the hypothesis that HRVs predispose to bacterial superinfection of the lower airways, similar to that of other community-acquired respiratory viruses.

Persistent rhinovirus infection in pediatric hematopoietic stem cell transplant recipients with impaired cellular immunity

BackgroundHRV infections are generally self-limiting in healthy subjects, whereas in immunocompromised hosts HRV infections can lead to severe complications and persistent infections. The persistence of HRV shedding could be due to the inefficient immunological control of a single infectious episode. ObjectivesTo investigate the clinical, virologic and immunologic characteristics of pediatric HSCT recipients with HRV-PI infection. Study designDuring the period 2006–2012, eight hematopoietic stem cell transplant (HSCT) recipients presented with persistent rhinovirus infection (HRV-PI, ≥30 days). Viral load and T-CD4+, T-CD8+, B and NK lymphocyte counts at the onset of infection were compared with those of fourteen HSCT recipients with acute HRV infection (HRV-AI, ≤15 days). ResultsThe median duration of HRV positivity in patients with HRV-PI was 61 days (range 30–174 days) and phylogenetic analysis showed the persistence of a single HRV type in all patients (100%). In HSCT recipients with HRV-PI, T-CD4+, T-CD8+ and NK cell counts at the onset of infection were significantly lower than those observed in recipients with HRV-AI (p<0.01), while B cell counts were similar in the two groups (p= 0.25). A decrease in HRV load was associated with a significant increase in T-CD4+, T-CD8+and NK lymphocyte counts in HRV-PI patients (p<0.01). ConclusionsThis study suggests a role for cellular immunity in HRV clearance and highlights the importance of its recovery for the control of HRV infection in HSCT recipients.

Molecular epidemiology of human rhinovirus infections in the pediatric emergency department

BackgroundHuman rhinovirus (HRV) infections are highly prevalent, genetically diverse, and associated with both mild upper respiratory tract and more severe lower tract illnesses (LRTI). ObjectiveTo characterize the molecular epidemiology of HRV infections in young children seeking acute medical care. Study designNasal swabs collected from symptomatic children <3 years of age receiving care in the Emergency and Urgent Care Departments at Seattle Children's Hospital were analyzed by a rapid polymerase chain reaction (PCR) system (FilmArray®) for multiple viruses including HRV/enterovirus. HRV-positive results were confirmed by laboratory-developed real-time reverse transcription PCR (LD-PCR). Clinical data were collected by chart review. A subset of samples was selected for sequencing using the 5′ noncoding region. Associations between LRTI and HRV species and genotypes were estimated using logistic regression analysis. ResultsOf 595 samples with HRV/enterovirus detected by FilmArray, 474 (80%) were confirmed as HRV by LD-PCR. 211 (96%) of 218 selected samples were sequenced; HRV species A, B, and C were identified in 133 (63%), 6 (3%), and 72 (34%), respectively. LRTI was more common in HRV-C than HRV-A illness episodes (adjusted OR [95% CI] 2.35[1.03–5.35). Specific HRV-A and HRV-C genotypes detected in multiple patients were associated with a greater proportion of LRTI episodes. In 18 patients with >1 HRV-positive illness episodes, a distinct genotype was detected in each. ConclusionDiverse HRV genotypes circulated among symptomatic children during the study period. We found an association between HRV-C infections and LRTI in this patient population and evidence of association between specific HRV genotypes and LRTI.

Molecular epidemiology of human rhinovirus in children with acute respiratory diseases in Chongqing, China.

Human rhinovirus-C (HRV-C) has been increasingly detected in patients with acute respiratory diseases (ARDs). Prolonged surveillance was performed on children with ARD to investigate the molecular epidemiology and clinical characteristics of HRV in Chongqing, China. Nasopharyngeal aspirates (NPA) were collected from hospitalized children with ARD during 2009–2012. HRV-C was genotyped by sequencing the VP4/VP2 coding region. Among the 1,567 NPAs obtained, 223 (14.2%) were HRV positive, and 75.3% of these 223 NPAs were co-infected with other viruses. HRV-A (54.7%) and HRV-C (39.9%) accounted for the majority of HRV infections. Logistic regression models demonstrated significant associations between HRV-A, HRV-C, and asthma attacks, as well as between HRV-C and wheezing. A phylogenetic tree showed that HRV-C2 was the predominant type of HRV-C, followed by HRV-C43, HRV-C1, and HRV-C17. Three novel genotypes were proposed on the basis of a low identity with the known HRVs. Our results showed that HRV-A and HRV-C were the predominant types of HRV infection, and HRV-C showed a high genetic variation in Chongqing, China. HRV infection was associated with asthma attacks and wheezing; furthermore, HRV infections played a minor role in causing severe pneumonia. This knowledge provides information for the prevention and control of HRV associated with ARDs.

Genetic diversity and clinical impact of human rhinoviruses in hospitalized and outpatient children with acute respiratory infection, Argentina

BackgroundHuman rhinoviruses (HRV) are recognized as a cause of upper and lower acute respiratory infections (ARI). The circulating species and their clinical impact were not described in Argentina. ObjectivesTo describe the molecular epidemiology of HRV in children and to determine the association of HRV species with outcome and severity.Study design: Hospitalized and outpatients children <6 years old with ARI without comorbidities (n=620) were enrolled (2008–2010). Demographic, clinical data and outcome were analyzed. HRV were identified by RT-PCR. Phylogenetic analysis and demographic reconstruction for HRV were performed in selected samples. ResultsHRV were detected in 252/620 (40.6%) of children; 8.5% in viral coinfection. Bronchiolitis (55%) and pneumonia (13%) were the most frequent clinical diagnosis. Of 202 inpatients with HRV: 72% required oxygen supplementation, 11% intensive care unit and 3% mechanical ventilation. HRV were identified as a risk factor for hospitalization (OR: 2.47).All three HRV species were detected being HRV-A (55%) and HRV-C (43%) the most frequent; HRV-B was infrequent (2%). Of 44 sequenced HRV, 30 genotypes were detected. Seven of them were the most prevalent and circulated during limited periods of time. The demographic reconstruction revealed a constant population size and a high turnover rate of genotypes. Demographic and clinical outcome were similar for HRV-A and HRV-C infections. ConclusionThis study highlights the clinical impact of HRV in children without comorbidities as a cause of lower ARI and hospitalization. The high frequency of HRV infections may be associated with the simultaneous circulation of genotypes and their high turnover rate.

Brief exposure to cigarette smoke impairs airway epithelial cell innate anti-viral defence

BackgroundHuman rhinovirus (hRV) infections commonly cause acute upper respiratory infections and asthma exacerbations. Environmental cigarette smoke exposure is associated with a significant increase in the risk for these infections in children. ObjectiveTo determine the impact of short-term exposure to cigarette smoke on innate immune responses of airway epithelial cells infected with hRV. MethodsA human bronchial epithelial cell line (HBEC-3KT) was exposed to cigarette smoke extract (CSE) for 30min and subsequently infected with hRV serotype 1B. Viral-induced cytokine release was measured with AlphaLISA and viral replication quantified by shed viral titer and intracellular viral copy number 24h post-infection. ResultsCSE induced a concentration-dependent decrease in CXCL10 (p<0.001) and IFN-β (p<0.001), with a 79% reduction at the highest dose with an associated 3-fold increase in shed virus. These effects were maintained when infection was delayed up to 24h post CSE exposure. Exogenous IFN-β treatment at t=0 after infection blunts the effects of CSE on viral replication (p<0.05). ConclusionA single exposure of 30min to cigarette smoke has a lasting impact on epithelial innate defence providing a plausible mechanism for the increase in respiratory infections seen in children exposed to second-hand tobacco smoke.

Influenza and other respiratory virus infections in outpatients with medically attended acute respiratory infection during the 2011-12 influenza season.

BackgroundRespiratory tract infections are a major cause of outpatient visits, yet only a portion is tested to determine the etiologic organism. Multiplex reverse transcriptase polymerase chain reaction (MRT-PCR) assays for detection of multiple viruses are being used increasingly in clinical settings.MethodsDuring January–April 2012, outpatients with acute respiratory illness (≤7 days) were tested for influenza using singleplex RT-PCR (SRT-PCR). A subset was assayed for 18 viruses using MRT-PCR to compare detection of influenza and examine the distribution of viruses and characteristics of patients using multinomial logistic regression.ResultsAmong 662 participants (6 months–82 years), detection of influenza was similar between the MRT-PCR and SRT-PCR (κ = 0·83). No virus was identified in 267 (40.3%) samples. Commonly detected viruses were human rhinovirus (HRV, 15·4%), coronavirus (CoV, 10·4%), respiratory syncytial virus (RSV, 8·4%), human metapneumovirus (hMPV, 8·3%), and influenza (6%). Co-detections were infrequent (6·9%) and most commonly occurred among those <18 years old. In regression analyses, compared with non-viral illnesses, RSV and hMPV were significantly more frequent in children and less frequent in 18- to 49-year-olds than in those ≥50 years (P = 0·01), fever was more common in hMPV and influenza infections (P = 0·008), nasal congestion was more frequent in CoV, HRV, hMPV, influenza and RSV infections (P = 0·001), and body mass index was higher among those with influenza (P = 0·036).ConclusionsUsing MRT-PCR, a viral etiology was found in three-fifths of patients with medically attended outpatient visits for acute respiratory illness during the influenza season; co-detected viruses were infrequent. Symptoms varied by viral etiology.