A comparison of hospitalized children with enterovirus D68 to those with rhinovirus

Detection of enterovirus D68 among children with severe acute respiratory infection in Myanmar

BACKGROUND

Enterovirus D68 (EV-D68) is an important reemerging pathogen that causes severe acute respiratory infection and acute flaccid paralysis, mainly in children. Since 2014, EV-D68 outbreaks have been reported in the United States, Europe, and east Asia; however, no outbreaks have been reported in southeast Asian countries, including Myanmar, during the previous 10 years.

METHODS

EV-D68 was detected in nasopharyngeal swabs from children with acute lower respiratory infections in Myanmar. The samples were previously collected from children aged 1 month to 12 years who had been admitted to the Yankin Children Hospital in Yangon, Myanmar, between May 2017 and January 2019. EV-D68 was detected with a newly developed EV-D68-specific real-time PCR assay. The clade was identified by using a phylogenetic tree created with the Bayesian Markov chain Monte Carlo method.

RESULTS

During the study period, nasopharyngeal samples were collected from 570 patients. EV-D68 was detected in 42 samples (7.4 %)-11 samples from 2017 to 31 samples from 2018. The phylogenetic tree revealed that all strains belonged to clade B3, which has been the dominant clade worldwide since 2014. We estimate that ancestors of currently circulating genotypes emerged during the period 1980-2004.

CONCLUSIONS

To our knowledge, this is the first report of EV-D68 detection in children with acute lower respiratory infections in Yangon, Myanmar, in 2017-2018. Detection and detailed virologic analyses of EV-D68 in southeast Asia is an important aspect of worldwide surveillance and will likely be useful in better understanding the worldwide epidemiologic profile of EV-D68 infection.

Seroprevalence of Enterovirus D68 Infection among Humans: A Systematic Review and Meta-Analysis

INTRODUCTION

Human enterovirus D68 (EV-D68), which belongs to enteroviruses of the small RNA family, is a type of enterovirus that can cause acute respiratory tract infection and central nervous system diseases. This study systematically analysed and summarized EV-D68 antibody studies in databases and identified the seropositivity rates of different regions, ages, and sexes.

METHODS

Meta-analysis was performed using STATA 16.0 software. I2 and Q tests were used to analyse the heterogeneity of the included studies. Meta-regression analysis was performed for different groups, and Egger's linear regression analysis was used to evaluate publication bias.

RESULTS

The results of multiple studies indicated that the serological prevalence range of EV-D68 antibody was 17.78-96.69%. The results of the meta-analysis showed that the seropositivity rate of EV-D68 antibody was 76% (95% confidence interval [CI]: 67-84%), among which that of the Chinese population was 74% (95% CI: 61-86%) and that of other countries was 79% (95% CI: 65-91%). At the same time, a subgroup analysis was conducted. The seroprevalence of EV-D68 antibody was related to age but not sex or region.

CONCLUSION

The seropositivity rate was lower in the below 5-year age group; however, it gradually increased with age. The results of this study showed that EV-D68 infection was widespread in the population, and the current clinical infection situation could not reflect the actual epidemic situation of the virus, among which children under 5 years old were vulnerable to infection, which should be given greater attention for epidemic prevention and control.

Epidemiology and Immunopathogenesis of Virus Associated Asthma Exacerbations

Asthma is a common airway disease, affecting millions of people worldwide. Although most asthma patients experience mild symptoms, it is characterized by variable airflow limitation, which can occasionally become life threatening in the case of a severe exacerbation. The commonest triggers of asthma exacerbations in both children and adults are viral infections. In this review article, we will try to investigate the most common viruses triggering asthma exacerbations and their role in asthma immunopathogenesis, since viral infections in young adults are thought to trigger the development of asthma either right away after the infection or at a later stage of their life. The commonest viral pathogens associated with asthma include the respiratory syncytial virus, rhinoviruses, influenza and parainfluenza virus, metapneumovirus and coronaviruses. All these viruses exploit different molecular pathways to infiltrate the host. Asthmatics are more prone to severe viral infections due to their unique inflammatory response, which is mostly characterized by T2 cytokines. Unlike the normal T1 high response to viral infection, asthmatics with T2 high inflammation are less potent in containing a viral infection. Inhaled and/or systematic corticosteroids and bronchodilators remain the cornerstone of asthma exacerbation treatment, and although many targeted therapies which block molecules that viruses use to infect the host have been used in a laboratory level, none has been yet approved for clinical use. Nevertheless, further understanding of the unique pathway that each virus follows to infect an individual may be crucial in the development of targeted therapies for the commonest viral pathogens to effectively prevent asthma exacerbations. Finally, biologic therapies resulted in a complete change of scenery in the treatment of severe asthma, especially with a T2 high phenotype. All available data suggest that monoclonal antibodies are safe and able to drastically reduce the rate of viral asthma exacerbations.

Prevalence and clinical presentation of EV-D68 infections in Kansas City children during the 2022 season

Seasonal EV-D68 infections can strain medical care resources due to increased pediatric hospitalizations for respiratory illness. In this study, we examine Kansas City's 2022 EV-D68 season. Rhinovirus/enterovirus (RV/EV) positive respiratory specimens from standard of care testing were salvaged and tested by EV-D68 specific PCR. Of the 1412 respiratory specimens tested from July 1 to September 15, 2022, 346 (23%) were positive for RV/EV and EV-D68 was detected in 134/319 (42%) salvaged RV/EV positive specimens. The median age of children with EV-D68 infections was 35.2 months (IQR 16.1, 67.3), which was older than children with non-EV-D68 RV/EV infections (16 months, IQR 5, 47.8), but younger than children infected during the 2014 EV-D68 outbreak. EV-D68 infection was more likely to cause severe disease in children with asthma compared to those without asthma. Real-time EV-D68 monitoring for outbreaks could potentially improve resource utilization by hospitals and help prepare for surges of respiratory disease.

The pathogenesis and virulence of enterovirus-D68 infection

In 2014, enterovirus D68 (EV-D68) emerged causing outbreaks of severe respiratory disease in children worldwide. In a subset of patients, EV-D68 infection was associated with the development of central nervous system (CNS) complications, including acute flaccid myelitis (AFM). Since then, the number of reported outbreaks has risen biennially, which emphasizes the need to unravel the systemic pathogenesis in humans. We present here a comprehensive review on the different stages of the pathogenesis of EV-D68 infection – infection in the respiratory tract, systemic dissemination and infection of the CNS – based on observations in humans as well as experimental in vitro and in vivo studies. This review highlights the knowledge gaps on the mechanisms of systemic dissemination, routes of entry into the CNS and mechanisms to induce AFM or other CNS complications, as well as the role of virus and host factors in the pathogenesis of EV-D68.

Outbreak of Enterovirus D68 Among Children in Japan-Worldwide Circulation of Enterovirus D68 Clade B3 in 2018

BACKGROUND

Enterovirus D68 (EV-D68) causes asthma-like respiratory infection in children. Several EV-D68 outbreaks have been reported worldwide since the largest outbreak occurred in the United States in 2014. We experienced an accumulation of pediatric cases with asthma-like respiratory illness in Niigata, Japan, in 2018.

STUDY DESIGN

To determine whether EV-D68 was responsible for the case accumulation, this prospective observational study evaluated children hospitalized in 1 of 8 hospitals with asthma-like respiratory illness in Niigata, Japan, during October and November 2018. Diagnoses were made by EV-D68-specific RT-PCR using nasopharyngeal samples. The clade was identified by sequence analyses, and a phylogenetic tree was created. To evaluate seasonal variation, data from pediatric cases with asthma-like respiratory illness in 2018 were retrospectively analyzed.

RESULTS

In 2018, 114 children were hospitalized with asthma-like respiratory illness in October and November, and 47 nasopharyngeal samples were collected. EV-D68 was detected in 22/47 (47%) patients during the study period. The phylogenetic tree revealed that all strains belonged to the clade B3 branch, which has been detected worldwide every 2 years since 2014.

CONCLUSIONS

EV-D68 was the associated pathogen for asthma-like respiratory illness in children in Japan in 2018. Clade B3, the dominant clade in outbreaks worldwide, was responsible for the outbreak. Detection and detailed virologic analysis of EV-D68 is important as part of worldwide surveillance, as it will aid in understanding the epidemiologic characteristics of EV-D68 infection.

Dynamics and predisposition of respiratory viral co-infections in children and adults

OBJECTIVES

The epidemiology of respiratory co-infection pairings is poorly understood. Here we assess the dynamics of respiratory viral co-infections in children and adults and determine predisposition for or against specific viral pairings.

METHODS

Over five respiratory seasons from 30 November 2013 through 6 June 2018, the mono-infection and co-infection prevalence of 13 viral pathogens was tabulated at The Cleveland Clinic. Employing a model to proportionally distribute viral pairs using individual virus co-infection rate with prevalence patterns of concurrent co-circulating viruses, we compared predicted occurrence with observed occurrence of 132 viral pairing permutations using binomial analysis.

RESULTS

Of 30 535 respiratory samples, 9843 (32.2%) were positive for at least one virus and 1018 (10.8%) of these were co-infected. Co-infected samples predominantly originated from children. Co-infection rate in paediatric population was 35.0% (2068/5906), compared with only 5.8% (270/4591) in adults. Adenovirus C (ADVC) had the highest co-infection rate (426/623, 68.3%) while influenza virus B had the lowest (55/546, 10.0%). ADVC-rhinovirus (HRV), respiratory syncytial virus A (RSVA)-HRV and RSVB-HRV pairings occurred at significantly higher frequencies than predicted by the proportional distribution model (p < 0.05). Additionally, several viral pairings had fewer co-infections than predicted by our model: notably metapneumovirus (hMPV)-parainfluenza virus 3, hMPV-RSVA and RSVA-RSVB.

CONCLUSIONS

This is one of the largest studies on respiratory viral co-infections in children and adults. Co-infections are substantially more common in children, especially under 5 years of age, and the most frequent pairings occurred at a higher frequency than would be expected by random. Specific pairings occur at altered rates compared with those predicted by proportional distribution, suggesting either direct or indirect interactions result between specific viral pathogens.

Respiratory illness and acute flaccid myelitis in the Tokai district in 2018

BACKGROUND

An outbreak of acute flaccid myelitis was chronologically correlated with an outbreak of severe respiratory illness in Japan in 2015. We hypothesized that increases in children hospitalized with severe respiratory illnesses might also be associated with increase in acute flaccid myelitis in autumn 2018.

METHODS

We explored the temporal correlations between respiratory illness outbreaks and acute flaccid myelitis during autumn season between 2016 and 2018 using questionnaire surveys. One questionnaire explored the monthly numbers of children with acute flaccid myelitis, Guillain-Barré syndrome, and other acute flaccid paralyses. The other questionnaire explored the monthly numbers of children hospitalized with respiratory illnesses associated with wheezing. A correlation between the monthly numbers of children with acute flaccid myelitis and those with respiratory illness was analyzed using the Pearson correlation test.

RESULTS

Although the number of patients hospitalized with respiratory illness did not correlate with the number of those admitted with myelitis, increases in children aged 7-12 and 13-19 years requiring intensive care unit admission correlated temporally with an outbreak of acute flaccid myelitis.

CONCLUSIONS

An increase in intensive care unit admissions to treat respiratory disease occurred in association with a cluster of acute flaccid myelitis. An increase in the number of intensive care unit admissions due to respiratory illness may be a clue to expect the occurrence of acute flaccid myelitis.

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.

Genomic analysis of serologically untypable human enteroviruses in Taiwan

Background

Human enteroviruses contain over 100 serotypes. We have routinely conducted enterovirus surveillance in northern Taiwan; but about 10% of isolates could not be serotyped using traditional assays. Next-generation sequencing (NGS) is a powerful tool for genome sequencing.

Methods

In this study, we established an NGS platform to conduct genome sequencing for the serologically untypable enterovirus isolates.

Results

Among 130 serologically untypable isolates, 121 (93%) of them were classified into 29 serotypes using CODEHOP (COnsensus-DEgenerate Hybrid Oligonucleotide Primer)-based RT-PCR to amplify VP1 genes (VP1-CODEHOP). We further selected 52 samples for NGS and identified 59 genome sequences from 51 samples, including 8 samples containing two virus genomes. We also detected 23 genome variants (nucleotide identity < 90% compared with genome sequences in the public domain) which were potential genetic recombination, including 9 inter-serotype recombinants and 14 strains with unknown sources of recombination.

Conclusions

We successfully integrated VP1-CODEHOP and NGS techniques to conduct genomic analysis of serologically untypable enteroviruses.

Electronic supplementary material

The online version of this article (10.1186/s12929-019-0541-x) contains supplementary material, which is available to authorized users.

Epidemiology of Infections and Development of Asthma

Asthma and allergic diseases have become more prevalent, although the reasons for this increase in disease burden are not known. Understanding why these diseases have become more common requires knowledge of the disease pathogenesis. Multiple studies have identified respiratory viral infections and atypical bacteria as potential etiologic agents underlying the development of asthma (and possibly allergies). This review discusses the epidemiology and potential mechanistic studies that provide links between these infectious agents and the development (and exacerbation) of asthma. These studies provide insight into the increase in disease prevalence and have identified potential targets for future therapeutic intervention.

Enterovirus D68 infection induces IL-17-dependent neutrophilic airway inflammation and hyperresponsiveness

Enterovirus D68 (EV-D68) shares biologic features with rhinovirus (RV). In 2014, a nationwide outbreak of EV-D68 was associated with severe asthma-like symptoms. We sought to develop a mouse model of EV-D68 infection and determine the mechanisms underlying airway disease. BALB/c mice were inoculated intranasally with EV-D68 (2014 isolate), RV-A1B, or sham, alone or in combination with anti-IL-17A or house dust mite (HDM) treatment. Like RV-A1B, lung EV-D68 viral RNA peaked 12 hours after infection. EV-D68 induced airway inflammation, expression of cytokines (TNF-α, IL-6, IL-12b, IL-17A, CXCL1, CXCL2, CXCL10, and CCL2), and airway hyperresponsiveness, which were suppressed by anti-IL-17A antibody. Neutrophilic inflammation and airway responsiveness were significantly higher after EV-D68 compared with RV-A1B infection. Flow cytometry showed increased lineage-, NKp46-, RORγt+ IL-17+ILC3s and γδ T cells in the lungs of EV-D68-treated mice compared with those in RV-treated mice. EV-D68 infection of HDM-exposed mice induced additive or synergistic increases in BAL neutrophils and eosinophils and expression of IL-17, CCL11, IL-5, and Muc5AC. Finally, patients from the 2014 epidemic period with EV-D68 showed significantly higher nasopharyngeal IL-17 mRNA levels compared with patients with RV-A infection. EV-D68 infection induces IL-17-dependent airway inflammation and hyperresponsiveness, which is greater than that generated by RV-A1B, consistent with the clinical picture of severe asthma-like symptoms.

Enterovirus D-68 in children presenting for acute care in the hospital setting

BACKGROUND

Severe respiratory disease associated with enterovirus D68 (EV-D68) has been reported in hospitalized pediatric patients. Virologic and clinical characteristics of EV-D68 infections exclusively in patients presenting to a hospital Emergency Department (ED) or urgent care have not been well defined.

METHODS

Mid-nasal swabs from pediatric patients with respiratory symptoms presenting to the ED or urgent care were evaluated using a commercial multiplex PCR platform. Specimens positive for rhinovirus/enterovirus (HRV/EV) were subsequently tested using real-time reverse-transcriptase PCR for EV-D68. The PCR cycle threshold (CT) was used as a viral load proxy. Clinical outcomes were compared between patients with EV-D68 and patients without EV-D68 who tested positive for HRV/EV.

RESULTS

From August to December 2014, 511 swabs from patients with HRV/EV were available. EV-D68 was detected in 170 (33%) HRV/EV-positive samples. In multivariable models adjusted for age and underlying asthma, patients with EV-D68 were more likely to require hospitalization for respiratory reasons (odds ratio (OR): 3.11, CI: 1.85-5.25), require respiratory support (OR: 1.69, CI: 1.09-2.62), have confirmed/probable lower respiratory tract infection (LRTI; OR: 3.78, CI: 2.03-7.04), and require continuous albuterol or steroids (OR: 3.91, CI: 2.22-6.88 and OR: 4.73, CI: 2.65-8.46, respectively). Higher EV-D68 viral load was associated with need for respiratory support and LRTI in multivariate models.

CONCLUSIONS

Among pediatric patients presenting to the ED or urgent care, EV-D68 causes more severe disease than non-EV-D68 HRV/EV independent of underlying asthma. High viral load was associated with worse clinical outcomes. Rapid and quantitative viral testing may help identify and risk stratify patients.

Comparison of the Severity of Respiratory Disease in Children Testing Positive for Enterovirus D68 and Human Rhinovirus

OBJECTIVE

To compare the characteristics and severity of respiratory disease in children testing positive for enterovirus D68 (EV-D68) and for human rhinovirus (RhV).

STUDY DESIGN

A retrospective single center study of children presenting with acute respiratory symptoms and positive polymerase chain reaction for RhV/EV from September 1, 2014 through October 31, 2014 was performed. Specimens were subsequently tested specifically for EV-D68 and specimens identified as RhV were subtyped when possible into RhV-A, RhV-B, and RhV-C species. Clinical manifestations in patients with EV-D68 were compared with those with non-EV-D68, RhV, and RhV-C.

RESULTS

Of the 173 patients included in the analysis, 72 tested positive for EV-D68, 61 for RhV, and 30 for RhV-C. There were significantly fewer infants in the EV-D68 group. Patients with EV-D68 were more likely than those without EV-D68, and specifically with RhV-C, to have fever and wheezing. Patients with EV-D68 received more magnesium sulfate for respiratory distress not responding adequately to repeated doses of inhaled albuterol. Hospitalized patients with EV-D68 received more bronchodilator therapy than patients with RhV. Patients with EV-D68 were more likely to be admitted to the intensive care unit and were older than patients without EV-D68. There was no difference in length of overall hospitalization or time in the pediatric intensive care unit.

CONCLUSIONS

Children with EV-D68 appeared to have more severe respiratory disease on admission than children with RhV as evidenced by higher rates of fever, wheezing, bronchodilator use and pediatric intensive care unit admission. Despite the initial difference in severity, no significant difference in length of stay was found suggesting that patients with EV-D68 recovered as quickly as other groups.