Clinical severity of pediatric respiratory illness with enterovirus D68 compared with rhinovirus or other enterovirus genotypes

Respiratory presentation of patients infected with enterovirus D68 in Taiwan

BACKGROUND

Enterovirus-D68 (EV-D68) has been endemic in Taiwan for some years with a small number of positive cases. Detailed information about respiratory presentation is lacking. This study characterized the clinical course in children admitted to the medical center and regional hospital in Taichung during 2015.

METHODS

Retrospective chart review of patients with confirmed EV-D68 infection admitted to the medical center and regional hospital in Taichung with respiratory symptoms in the second half of 2015. Past medical history, clinical presentation, management, and course in hospital were collected and analyzed. Simple demographic data and clinical symptoms were also collected from patients confirmed with EV-D68 infection who visited clinics in Taichung.

RESULTS

Six children were included. Two patients had a prior history of asthma or recurrent dyspnea, and one had other preexisting medical comorbidities. One child was admitted to the pediatric intensive care unit. All the patients were cured. Cough, rhinorrhea, tachypnea and fever were the most common clinical symptoms among inpatients, while influenza-like illness (ILI) was prevalent in outpatients.

CONCLUSION

EV-D68 infection resulted in respiratory presentations of asthma-like illness in the hospitalized pediatric population. Patients with a prior history of asthma or recurrent dyspnea appear to be more severely affected.

The Fraction of Rhinovirus Detections Attributable to Mild and Severe Respiratory Illness in a Setting of High Human Immunodeficiency Virus Prevalence, South Africa, 2013-2015

BACKGROUND

The association of rhinovirus (RV) detection to illness is poorly understood.

METHODS

We enrolled case patients hospitalized with severe respiratory illness (SRI) at 2 hospitals and outpatients with influenza-like illness (ILI) and asymptomatic individuals (controls) from 2 affiliated clinics during 2013-2015. We compared the RV prevalence among ILI and SRI cases to those of controls stratified by human immunodeficiency virus (HIV) serostatus using penalized logistic regression. The attributable fraction (AF) was calculated.

RESULTS

During 2013-2015, RV was detected in 17.4% (368/2120), 26.8% (979/3654), and 23.0% (1003/4360) of controls, ILI cases, and SRI cases, respectively. The RV AF (95% confidence interval) was statistically significant among children aged <5 years (ILI: 44.6% [30.7%-55.7%] and SRI: 50.3% [38.6%-59.9%]; P < .001) and individuals aged ≥5 years (ILI: 62.9% [54.4%-69.8%] and SRI: 51.3% [38.7%-61.3%]; P < .001) as well as among HIV-infected (ILI: 59.9% [45.8%-70.3%] and SRI: 39.8% [22.3%-53.3%]; P < .001) and HIV-uninfected (ILI: 53.6% [44.7%-61.1%] and SRI: 55.3% [45.6%-63.2%]; P < .001) individuals.

CONCLUSIONS

Although RV detection was common among controls, it was also associated with a substantial proportion of clinical illness across age groups, irrespective of HIV status.

Enterovirus D68 respiratory infection in a children's hospital in Japan in 2015

BACKGROUND

Outbreaks of enterovirus D68 (EV-D68) respiratory infections in children were reported globally in 2014. In Japan, there was an EV-D68 outbreak in the autumn of 2015 (September-October). The aim of this study was to compare EV-D68-specific polymerase chain reaction (PCR)-positive and EV-D68-specific PCR-negative patients.

METHODS

Pediatric patients admitted for any respiratory symptoms between September and October 2015 were enrolled. Nasopharyngeal swabs were tested for multiplex respiratory virus PCR and EV-D68-specific reverse transcription-PCR. EV-D68-specific PCR-positive and -negative patients were compared regarding demographic data and clinical information.

RESULTS

A nasopharyngeal swab was obtained from 76 of 165 patients admitted with respiratory symptoms during the study period. EV-D68 was detected in 40 samples (52.6%). Median age in the EV-D68-specific PCR-positive and -negative groups was 3.0 years (IQR, 5.5 years) and 3.0 years (IQR, 4.0 years), respectively. The rates of coinfection in the two groups were 32.5% and 47.2%, respectively. There was no significant difference in the history of asthma or recurrent wheezing, length of hospitalization, or pediatric intensive care unit admission rate between the groups. The median days between symptom onset and admission was significantly lower for the EV-D68-positive group (3.0 days vs 5.0 days, P = 0.001). EV-D68 was identified as clade B on phylogenetic analysis. No cases of acute flaccid myelitis were encountered.

CONCLUSIONS

More than half of the samples from the children admitted with respiratory symptoms were positive for EV-D68-specific PCR during the outbreak. Asthma history was not associated with the risk of developing severe respiratory infection.

New and Emerging Infections of the Lung

In this era of rapid globalization and frequent travel, emerging viral infections have gained an immense potential to spread at an unprecedented speed and scale compared with the past. This poses a significant challenge to coordinated international efforts in global surveillance and infection control.

Significantly, respiratory viral infections, spread mostly via droplet transmission, are extremely contagious and have caused significant morbidity and mortality during outbreaks in the last decade. Molecular diagnostics via reverse transcriptase polymerase chain reaction (RT-PCR) have been key in the rapid diagnosis of most of these viral infections. However, a high index of suspicion and early institution of appropriate isolation measures remain as the mainstay in the control and containment of the spread of these viral infections. Although treatment for most of the viral infections remains supportive, efficacious antiviral agents against influenza infections exist.

The infections discussed in this chapter include those first described in the 2000s: Middle East respiratory syndrome coronavirus (MERS-CoV) and metapneumovirus and rhinovirus C as well as those that have been described in the past but have reemerged in the last decade in outbreaks resulting in significant morbidity and mortality, including adenovirus, influenza virus, and enterovirus D68 (EV-D68).

Andrographolide Prevents EV-D68 Replication by Inhibiting the Acidification of Virus-Containing Endocytic Vesicles

Enterovirus D68 (EV-D68) has emerged as a significant respiratory pathogen that can cause severe respiratory disease and acute neurologic disease. At present, there are no approved antiviral agents or vaccines for EV-D68. In this study, we demonstrate that andrographolide (ADO), an active component of Andrographis paniculata, exerts substantial antiviral activity against EV-D68 infection. ADO treatment dramatically inhibited EV-D68 RNA replication (EC₅₀ = 3.45 μM) and protein synthesis without producing significant cytotoxicity at virucidal concentrations. ADO-treated cells did not show any changes in host immune activation, EV-D68 attachment, or viral 5′ UTR activity. Using a pH-sensitive fluorescent indicator system for endocytosis in living cells, we found that ADO prevented the acidification of endocytic vesicles after receptor-mediated endocytosis. Finally, we showed that ADO inhibited the viral replication of circulating isolated EV-D68 strains. In summary, our results demonstrate that ADO suppresses EV-D68 replication by targeting the maturation of virus-containing endosomes of EV-D68. This mechanism represents a promising strategy for drug development.

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.

Severe Respiratory Illness Associated With Rhinovirus During the Enterovirus D68 Outbreak in the United States, August 2014-November 2014

Background

In 2014, a nationwide outbreak of severe respiratory illness occurred in the United States, primarily associated with enterovirus D68 (EV-D68). A proportion of illness was associated with rhinoviruses (RVs) and other enteroviruses (EVs), which we aimed to characterize further.

Methods

Respiratory specimens from pediatric and adult patients with respiratory illness were submitted to the Centers for Disease Control and Prevention during August 2014-November 2014. While initial laboratory testing focused on identification of EV-D68, the negative specimens were typed by molecular sequencing to identify additional EV and RV types. Testing for other pathogens was not conducted. We compared available clinical and epidemiologic characteristics among patients with EV-D68 and RV species A-C identified.

Results

Among 2629 typed specimens, 1012 were EV-D68 (39%) and 81 (3.1%) represented 24 other EV types; 968 were RVs (37%) covering 114 types and grouped into 3 human RV species (RV-A, 446; RV-B, 133; RV-C, 389); and 568 (22%) had no RV or EV detected. EV-D68 was more frequently identified in patients who presented earlier in the investigation period. Among patients with EV-D68, RV-A, RV-B, or RV-C, the age distributions markedly differed. Clinical syndromes and intensive care unit admissions by age were largely similar.

Conclusions

RVs were commonly associated with severe respiratory illness during a nationwide outbreak of EV-D68, and most clinical. Characteristics were similar between groups. A better understanding of the epidemiology of RVs and EVs is needed to help inform development and use of diagnostic tests, therapeutics, and preventive measures.

Effect of enterovirus infections on asthma in young children: A national cohort study

BACKGROUND

We conducted a cohort study to determine the relationship between enterovirus (EV) infection and asthma.

MATERIALS AND METHODS

From the National Health Insurance Research Database of Taiwan, we identified patients who received a new diagnosis of asthma and concurrent treatment between January 2000 and December 2011 (EV cohort: n = 208 213; non-EV cohort: n = 208 213). Cox proportional hazards regression analysis was performed to determine and compare the adjusted hazard ratios (aHRs) of asthma between these 2 cohorts. Kaplan-Meier analysis was conducted to assess the differences in the cumulative incidence curves of asthma between the 2 cohorts.

RESULTS

The overall aHR of asthma was 1.48-fold higher in the EV cohort than in the non-EV cohort (95% confidence interval = 1.45-1.50). The aHR of asthma was higher in the EV cohort than in the non-EV cohort, comprising children aged ≤5 years, regardless of sex, sociodemographic factors (urbanization level and parental occupation) or comorbidities. The risk of asthma was higher in 1-3, 4-6, 7-9 and 10-12 months (all P < .001), particularly in those with a higher frequency of admission (>5 per year).

CONCLUSION

The incidence of asthma was higher in the EV cohort than in the non-EV cohort, comprising children aged ≤5 years, regardless of sex, urbanization level, parental occupation or season. In particular, the risk of asthma was higher in children with a higher frequency of admission, even in the absence of atopy or other respiratory infections.

Clinical Course of Enterovirus D68 in Hospitalized Children

BACKGROUND

Enterovirus D68 (EV-D68) has been sporadically reported as a cause of respiratory tract infections. In 2014, an international outbreak of EV-D68 occurred and caused severe respiratory disease in the pediatric population.

METHODS

A retrospective chart review was performed of children admitted to Children's Mercy Hospital from August 1, 2014, to September 15, 2014, with positive multiplex polymerase chain reaction testing for EV/rhinovirus (RV). Specimens were subsequently tested for EV-D68, and clinical data were obtained from the medical records. Patients with EV-D68 were compared with children presenting simultaneously with other EV/RV.

RESULTS

Of 542 eligible specimens, children with EV-D68 were significantly older than children with other EV/RV (4.6 vs. 2.2 years, P < 0.001). Children with EV-D68 were more likely to have a history of asthma (38.6% vs. 30.0%, P = 0.04) or recurrent wheezing (22.1% vs. 14.8%, P = 0.04). EV-D68-positive children more commonly received supplemental oxygen (86.7% vs. 65.0%, P < 0.001), albuterol (91.2% vs. 65.5%, P < 0.001) and corticosteroids (82.9% vs. 58.6%, P < 0.001). Age ≥5 years was an independent risk factor for intensive care unit management in EV-D68-infected children. Children with a history of asthma or recurrent wheezing and EV-D68 received supplemental oxygen (92.7% vs. 82.4%, P = 0.007) and magnesium (42.7% vs. 29.7%, P = 0.03) at higher rates and more continuous albuterol (3 vs. 2 hours, P = 0.03) than those with other EV/RV.

CONCLUSIONS

EV-D68 causes severe disease in the pediatric population, particularly in children with a history of asthma or recurrent wheezing. EV-D68-positive children are more likely to require therapy for refractory bronchospasm and may need intensive care unit- level care.

Enterovirus D68-Associated Community-Acquired Pneumonia in the Pediatric Age Group

PURPOSE OF REVIEW

This review summarizes the current knowledge regarding the role of Enterovirus D68 (EV-D68) in community-acquired pneumonia (CAP) in children.

RECENT FINDINGS

EV-D68 is an emergent viral pathogen. Since its first isolation in 1962 in California in four children suffering from CAP and bronchiolitis, EV-D68 has been rarely detected from respiratory specimens. However, recently, EV-D68 infection has raised concerns in the international community because of outbreaks in 2014 in the USA and the increased number of children with EV-D68-associated severe respiratory illnesses, including pneumonia, that have been reported in many other countries around the world. EV-D68 causes severe and life-threatening respiratory diseases in the pediatric population, particularly in children with underlying conditions such as prematurity or chronic diseases. Since no specific treatment or vaccinations are available for EV-D68 infections, greater surveillance as well as the use of sensitive and rapid diagnostic methods are essential to prevent and manage new outbreaks.

Enterovirus D68 in Hospitalized Children: Sequence Variation, Viral Loads and Clinical Outcomes

Background

An outbreak of enterovirus D68 (EV-D68) caused severe respiratory illness in 2014. The disease spectrum of EV-D68 infections in children with underlying medical conditions other than asthma, the role of EV-D68 loads on clinical illness, and the variation of EV-D68 strains within the same institution over time have not been described. We sought to define the association between EV-D68 loads and sequence variation, and the clinical characteristic in hospitalized children at our institution from 2011 to 2014.

Methods

May through November 2014, and August to September 2011 to 2013, a convenience sample of nasopharyngeal specimens from children with rhinovirus (RV)/EV respiratory infections were tested for EV-D68 by RT-PCR. Clinical data were compared between children with RV/EV-non-EV-D68 and EV-D68 infections, and among children with EV-D68 infections categorized as healthy, asthmatics, and chronic medical conditions. EV-D68 loads were analyzed in relation to disease severity parameters and sequence variability characterized over time.

Results

In 2014, 44% (192/438) of samples tested positive for EV-D68 vs. 10% (13/130) in 2011–13 (p<0.0001). PICU admissions (p<0.0001) and non-invasive ventilation (p<0.0001) were more common in children with EV-D68 vs. RV/EV-non-EV-D68 infections. Asthmatic EV-D68+ children, required supplemental oxygen administration (p = 0.03) and PICU admissions (p <0.001) more frequently than healthy children or those with chronic medical conditions; however oxygen duration (p<0.0001), and both PICU and total hospital stay (p<0.01) were greater in children with underlying medical conditions, irrespective of viral burden. By phylogenetic analysis, the 2014 EV-D68 strains clustered into a new sublineage within clade B.

Conclusions

This is one of the largest pediatric cohorts described from the EV-D68 outbreak. Irrespective of viral loads, EV-D68 was associated with high morbidity in children with asthma and co-morbidities. While EV-D68 circulated before 2014, the outbreak isolates clustered differently than those from prior years.

Respiratory Presentation of Pediatric Patients in the 2014 Enterovirus D68 Outbreak

Background. In the fall of 2014, a North American outbreak of enterovirus D68 resulted in a significant number of pediatric hospital admissions for respiratory illness throughout North America. This study characterized the clinical presentation and risk factors for a severe clinical course in children admitted to British Columbia Children's Hospital during the 2014 outbreak. Methods. Retrospective chart review of patients with confirmed EV-D68 infection admitted to BCCH with respiratory symptoms in the fall of 2014. Past medical history, clinical presentation, management, and course in hospital was collected and analyzed using descriptive statistics. Comparison was made between those that did and did not require ICU admission to identify risk factors. Results. Thirty-four patients were included (median age 7.5 years). Fifty-three percent of children had a prior history of wheeze, 32% had other preexisting medical comorbidities, and 15% were previously healthy. Ten children (29%) were admitted to the pediatric intensive care unit. The presence of complex medical conditions (excluding wheezing) (P = 0.03) and copathogens was associated with PICU admission (P = 0.02). Conclusions. EV-D68 infection resulted in severe, prolonged presentations of asthma-like illness in the hospitalized pediatric population. Patients with a prior history of wheeze and preexisting medical comorbidities appear to be most severely affected, but the virus can also cause wheezing in previously well children.

What happened to enterovirus D68 infections in 2015?

BACKGROUND

Enterovirus-D68 (EV-D68) was observed in association with severe respiratory disease in children in North America and around the world in the fall of 2014.

OBJECTIVE

To compare fall 2014 detection rates with fall 2015 detection rates of EV-D68 in nasopharyngeal swab (NPS) samples collected for routine clinical care from a large regional laboratory in south-central Ontario.

METHOD

Consecutive NPS samples submitted from inpatients and outpatients in Hamilton, Niagara Region and Burlington to the Regional Virology Laboratory were tested with multiplex polymerase chain reaction (PCR) for rhinovirus/enterovirus (as a single target) and for other common respiratory viruses. All NPS samples positive for rhinovirus/enterovirus were reflexed to a lab-developed single target PCR for EV-D68 detection.

RESULTS

In 2014, between August 1 and October 31, 566 of 1,497 (38%, 95%CI 35-40%) NPS samples were rhino/enterovirus positive, of which 177 (31%, 95%CI 27-35%) were confirmed as EV-D68. In 2015, between August 1 and October 31, 472 of 1,630 (29%, 95%CI 27-31%) NPS samples were rhino/enterovirus positive, of which none (0%, upper limit 97.5%CI 0.8%) were confirmed to be EV-D68.

CONCLUSION

Based on testing results, there appears to be much less circulating EV-D68 in south central Ontario in 2015 than in 2014. Further studies would be helpful to determine if detection rates have also dramatically decreased in other regions in Canada and internationally.