Update on nonpolio enterovirus and parechovirus infections in neonates and young infants.

PURPOSE OF REVIEW: To review the epidemiology, clinical manifestations, and treatment strategies of nonpolio enterovirus and parechovirus (PeV) infections, and identify research gaps. RECENT FINDINGS: There is currently no approved antiviral agent for enterovirus or PeV infections, although pocapavir may be provided on a compassionate basis. Elucidation of the structure and functional features of enterovirus and PeV may lead to novel therapeutic strategies, including vaccine development. SUMMARY: Nonpolio human enterovirus and PeV are common childhood infections that are most severe among neonates and young infants. Although most infections are asymptomatic, severe disease resulting in substantial morbidity and mortality occurs worldwide and has been associated with local outbreaks. Long-term sequelae are not well understood but have been reported following neonatal infection of the central nervous system. The lack of antiviral treatment and effective vaccines highlight important knowledge gaps. Active surveillance ultimately may inform preventive strategies.

Genotypic Diversity of Childhood Rhinovirus Infections.

Our objective was to describe the distribution of rhinovirus (RV) by species and type in both symptomatic and asymptomatic children in a prospective study over multiple years. A large and diverse distribution of RV types was seen among children with and without symptoms. RV-A and RV-C were predominant at all visits.

Rhinovirus-A True Respiratory Threat or a Common Inconvenience of Childhood?

A decade-long neglect of rhinovirus as an important agent of disease in humans was primarily due to the fact that they were seen as less virulent and capable of causing only mild respiratory infections such as common cold. However, with an advent of molecular diagnostic methods, an increasing number of reports placed them among the pathogens found in the lower respiratory tract and recognized them as important risk factors for asthma-related pathology in childhood. As the spread of rhinovirus was not severely affected by the implementation of social distancing and other measures during the coronavirus disease 2019 (COVID-19) pandemic, its putative pathogenic role has become even more evident in recent years. By concentrating on children as the most vulnerable group, in this narrative review we first present classification and main traits of rhinovirus, followed by epidemiology and clinical presentation, risk factors for severe forms of the disease, long-term complications and the pathogenesis of asthma, as well as a snapshot of treatment trials and studies. Recent evidence suggests that the rhinovirus is a significant contributor to respiratory illness in both high-risk and low-risk populations of children.

Rhinovirus-induced epithelial RIG-I inflammasome suppresses antiviral immunity and promotes inflammation in asthma and COVID-19.

Rhinoviruses and allergens, such as house dust mite are major agents responsible for asthma exacerbations. The influence of pre-existing airway inflammation on the infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is largely unknown. We analyse mechanisms of response to viral infection in experimental in vivo rhinovirus infection in healthy controls and patients with asthma, and in in vitro experiments with house dust mite, rhinovirus and SARS-CoV-2 in human primary airway epithelium. Here, we show that rhinovirus infection in patients with asthma leads to an excessive RIG-I inflammasome activation, which diminishes its accessibility for type I/III interferon responses, leading to their early functional impairment, delayed resolution, prolonged viral clearance and unresolved inflammation in vitro and in vivo. Pre-exposure to house dust mite augments this phenomenon by inflammasome priming and auxiliary inhibition of early type I/III interferon responses. Prior infection with rhinovirus followed by SARS-CoV-2 infection augments RIG-I inflammasome activation and epithelial inflammation. Timely inhibition of the epithelial RIG-I inflammasome may lead to more efficient viral clearance and lower the burden of rhinovirus and SARS-CoV-2 infections.

Detection and genetic characterization of canine kobuvirus from stray dogs in Shanghai, China.

In this study, rectal samples collected from 60 stray dogs in dog shelters were screened for canine kobuvirus and other enteroviruses by quantitative real-time reverse transcription polymerase chain reaction. Canine kobuvirus was detected in 25% (15/60) of the samples. In the 15 positive samples, the coinfection rates of canine distemper virus, canine coronavirus, canine astrovirus, canine norovirus, and canine rotavirus were 26.67%, 20.00%, 73.33%, 0%, and 20.00%, respectively. Phylogenetic analysis based on partial VP1 sequences identified a novel canine kobuvirus that was a recombinant of canine and feline kobuvirus. Bayesian evolutionary analysis revealed that the rate of evolution of the VP1 gene of canine kobuvirus was 1.36 × 10-4 substitutions per site per year (95% highest posterior density interval, 6.28 × 10-7 - 4.30 × 10-4 substitutions per site per year). Finally, the divergence time of VP1 was around 19.44 years ago (95% highest posterior density interval, 12.96-27.57 years).

Asthma exacerbations: the Achilles heel of asthma care.

Asthma exacerbations significantly impact millions of patients worldwide to pose large disease burdens on affected patients, families, and health-care systems. Although numerous environmental factors cause asthma exacerbations, viral respiratory infections are the principal triggers. Advances in the pathophysiology of asthma have elucidated dysregulated protective immune responses and upregulated inflammation that create susceptibility and risks for exacerbation. Biologics for the treatment of severe asthma reduce rates of exacerbations and identify specific pathways of inflammation that contribute to altered pathophysiology, novel therapeutic targets, and informative biomarkers. Major steps to prevent exacerbations include the identification of molecular pathways whose blockage will prevent asthma attacks safely, predictably, and effectively.

Disruption of seasonal enterovirus and parechovirus detections in the CSF and plasma of children during the COVID-19 pandemic.

BACKGROUND: Enteroviruses (EV) and parechovirus (PeV) are a common cause of CNS infection in children. Both viruses demonstrate consistent seasonal patterns, with detections mainly in the summer-fall months. While research has shown COVID-19 pandemic-related disruption of traditional seasonality of respiratory pathogens, the pandemic's impact on non-respiratory pathogens is less understood. The aim of this study was to quantify the EV/PeV seasonal variations during pre-COVID years compared to variations observed during the COVID pandemic. METHODS: Patients with EV/PeV testing of CSF/plasma between January 2012 through September 2022 were identified. Restricted cubic spline methods were used to model the detections. Poisson models were utilized to model pre-COVID (2012-2019) EV/PeV detections. The expected seasonal trends from these models were then compared to the observed EV/PeV detections during the COVID pandemic (2020-2022). RESULTS: A total of 5199 patients were included. The annual pre-pandemic proportion of EV detections ranged between 7.5%-20.3%. PeV exhibited a biennial pattern with peak proportions between 8.0%-16.3%. EV/PeV detections during the COVID pandemic period, especially during 2020 and 2021, were considerably lower than would have been expected based on pre-pandemic modeling. However, PeV detections from January through September 2022 nearly reached the pre-pandemic modeled expectation, including instances of exceeded expectations. CONCLUSIONS: A significant disruption in expected seasonal EV/PeV detections was observed during the early phases of the COVID-19 pandemic. However, testing that occurred during summer-fall of 2022, when social mitigation initiatives were relaxed, showed a rapid increase in detections. Additional data are needed to further understand which public health initiatives are effective at decreasing EV/PeV transmission.

Effects of COVID-19 and Social Distancing on Rhinovirus Infections and Asthma Exacerbations.

Since their discovery in the 1950s, rhinoviruses (RVs) have been recognized as a major causative agent of the "common cold" and cold-like illnesses, accounting for more than 50% of upper respiratory tract infections. However, more than that, respiratory viral infections are responsible for approximately 50% of asthma exacerbations in adults and 80% in children. In addition to causing exacerbations of asthma, COPD and other chronic lung diseases, RVs have also been implicated in the pathogenesis of lower respiratory tract infections including bronchiolitis and community acquired pneumonia. Finally, early life respiratory viral infections with RV have been associated with asthma development in children. Due to the vast genetic diversity of RVs (approximately 160 known serotypes), recurrent infection is common. RV infections are generally acquired in the community with transmission occurring via inhalation of aerosols, respiratory droplets or fomites. Following the outbreak of coronavirus disease 2019 (COVID-19), exposure to RV and other respiratory viruses was significantly reduced due to social-distancing, restrictions on social gatherings, and increased hygiene protocols. In the present review, we summarize the impact of COVID-19 preventative measures on the incidence of RV infection and its sequelae.

High prevalence and clinical characteristics of respiratory infection by human rhinovirus in children from Lima-Peru during years 2009-2010.

INTRODUCTION: Human rhinovirus is a major cause of acute respiratory infections (ARIs) worldwide. Epidemiological data on human rhinovirus (RV) in Peru is still scarce, as well as its role in respiratory infections in children. Therefore, the aim of this study was to describe the prevalence of rhinovirus and to identify the circulating species in nasopharyngeal swabs from children with acute respiratory infections. MATERIALS AND METHODS: We analyzed nasopharyngeal swab samples that were collected from children younger than 17 years old, who had a clinical diagnosis of ARI from the "Hospital Nacional Cayetano Heredia" between May 2009 and December 2010. The original study recruited 767 inpatients with ARI, 559 samples of which were included and analyzed in the current study. Detection of rhinovirus and determination of rhinovirus species were characterized by PCR. RESULTS: Rhinovirus was detected in 42.22% samples (236/559), RV-A was detected in 10.17% (24/236) of the cases, RV-B in 16.53% (39/236), and RV-C in 73.31% (173/236). The age group with the highest number of cases was the 0-5 months group with 45.97%, followed by the 1-5 years group with 25.22%. Most of the positive RV cases, i.e., 86.44% (204/236), were hospitalized. The most common signs and symptoms found in patients who tested positive for RV were cough (72.88%), fever (68.64%), rhinorrhea (68.22%), and respiratory distress (61.44%). Infection with RV-A was associated with wheezing (p = 0.02). Furthermore, RV-C was related to cough (p = 0.01), wheezing (p = 0.002), and conjunctival injection (p = 0.03). A peak in RV-C cases was found in March (32 cases in 2010); June (18 cases in 2009 and 12 cases in 2010), which corresponds to the fall season in Peru; and also November (17 cases in 2009 and 4 cases in 2010), which corresponds to spring. RV-A and RV-B cases were constant throughout the year. CONCLUSION: In conclusion, we found a high prevalence of rhinovirus C infection among pediatric patients with acute respiratory infections in Lima, Peru. This viral infection was more common in children between 0 to 5 months old, and was associated with cough, wheezing, and conjunctival injection. Epidemiological surveillance of this virus should be strengthened/encouraged in Peru to determine its real impact on respiratory infections.

SIRT-1 connects autophagy and release of virus-containing vesicles during picornavirus infection (preprint)

ABSTRACT Enterovirus D68 is a re-emerging enterovirus which causes acute respiratory illness in infants. EV-D68 infection has recently been associated with Acute Flaccid Myelitis, a severe polio-like neurological disease that causes limb weakness and loss of muscle tone in infants. There is currently no FDA-approved drug or prophylactic vaccine against EV-D68. Here, we investigated the role of the histone deacetylase, SIRT-1, in autophagy and EV-D68 infection. We show that SIRT-1 plays an important role in both autophagy and EV-D68 infection. siRNA-mediated knockdown of the cellular protein blocks basal and stress-induced autophagy and reduces EV-D68 extracellular viral titers. The proviral activity of SIRT-1 does not require deacetylase activity, since transient expression of both wild-type and deacetylase-inactive SIRT-1 mutant plasmids increased EV-D68 release. In non-lytic conditions, EV-D68 is primarily released in extracellular vesicles, and SIRT-1 is required for this process. Knockdown of SIRT-1 further impedes EV-D68 release in the autophagy-deficient ATG-7 knockout cells. Knockdown of SIRT-1 also decreases titers of poliovirus (PV) and SARS-CoV-2, but not Coxsackievirus-B3 (CVB3). CVB3 is the only tested virus that fails to induce SIRT-1 translocation to the cytosol. Our data suggest a correlation between SIRT-1 translocation during viral infection and extracellular vesicle-mediated non-lytic release of infectious viral particles. SIGNIFICANCE Picornaviruses, including EV-D68, constitute a significant cause of human disease. EV-D68 infection generally causes mild respiratory tract infection in infants but has recently been implicated in a severe polio-like neurological disease, AFM. Given the lack of prophylactic vaccines or antivirals against EV-D68, identifying host factors that modulate EV-D68 infection is crucial. Here, we show that SIRT-1 regulates autophagy and EV-D68 infection. Knockdown of SIRT-1 blocked autophagy and impeded the non-lytic release of EV-D68 in extracellular vesicles. We also show that SIRT-1 modulates the release of SARS-CoV-2 and poliovirus but not Coxsackievirus-B3 virus. Our data suggest that many RNA viruses require SIRT-1 for egress and that targeting SIRT-1 could constitute a broad-spectrum antiviral strategy.

Retrospective evaluation of viral respiratory tract infections in a university hospital in Ankara, Turkey (2016-2019).

INTRODUCTION: Viruses are responsible for two-thirds of all acute respiratory tract infections. This study aims to retrospectively detect respiratory tract viruses in patients from all age groups who visited the hospital. METHODOLOGY: A total of 1592 samples from 1416 patients with respiratory tract symptoms were sent from several clinics to the Molecular Microbiology Laboratory at Gazi University Hospital from February 2016 to January 2019. Nucleic acid extraction from nasopharyngeal swabs, throat swabs or bronchoalveolar lavage (BAL) samples sent to our laboratory was done using a commercial automated system. Extracted nucleic acids were amplified by a commercial multiplex-real time Polymerase Chain Reaction (PCR) method, which can detect 18 viral respiratory pathogens. RESULTS: Among 1592 samples, 914 (57.4%) were positive for respiratory viruses. The most prevalent were rhinovirus (25.2%) and influenza A virus (12.1%), the least prevalent was the bocavirus (2.6%). Rhinovirus was the most detected as a single agent (21.2%, 194/914) among all positive cases, followed by coronavirus (9.3%, 85/914). The detection rates of coronavirus, human adenovirus, respiratory syncytial virus A/B, human parainfluenza viruses, human metapneumovirus-A/B, human parechovirus, enterovirus and influenza B virus were 9.9%, 8%, 7.7%, 5%, 3.4%, 3.1%, 3%, and 2.8%, respectively. CONCLUSIONS: The most detected viral agents in our study were influenza A virus and rhinovirus. Laboratory diagnosis of respiratory viruses is helpful to prevent unnecessary antibiotic use and is essential in routine diagnostics for antiviral treatment. Multiplex Real-time PCR method is fast and useful for the diagnosis of viral respiratory infections.

Development of a multiplex droplet digital PCR assay for detection of enterovirus, parechovirus, herpes simplex virus 1 and 2 simultaneously for diagnosis of viral CNS infections.

BACKGROUND: Enterovirus (EV), parechovirus (HPeV), herpes simplex virus 1 and 2 (HSV1/2) are common viruses leading to viral central nervous system (CNS) infections which are increasingly predominant but exhibit deficiency in definite pathogen diagnosis with gold-standard quantitative PCR method. Previous studies have shown that droplet digital PCR (ddPCR) has great potential in pathogen detection and quantification, especially in low concentration samples. METHODS: Targeting four common viruses of EV, HPeV, HSV1, and HSV2 in cerebrospinal fluid (CSF), we developed a multiplex ddPCR assay using probe ratio-based multiplexing strategy, analyzed the performance, and evaluated it in 97 CSF samples collected from patients with suspected viral CNS infections on a two-channel ddPCR detection system. RESULTS: The four viruses were clearly distinguished by their corresponding fluorescence amplitude. The limits of detection for EV, HPeV, HSV1, and HSV2 were 5, 10, 5, and 10 copies per reaction, respectively. The dynamic range was at least four orders of magnitude spanning from 2000 to 2 copies per reaction. The results of 97 tested clinical CSF specimens were identical to those deduced from qPCR/qRT-PCR assays using commercial kits. CONCLUSION: The multiplex ddPCR assay was demonstrated to be an accurate and robust method which could detect EV, HPeV, HSV1, and HSV2 simultaneously. It provides a useful tool for clinical diagnosis and disease monitoring of viral CNS infections.

Genetic diversity and epidemiology of human rhinovirus among children with severe acute respiratory tract infection in Guangzhou, China.

BACKGROUND: Human rhinovirus (HRV) is one of the major viruses of acute respiratory tract disease among infants and young children. This work aimed to understand the epidemiological and phylogenetic features of HRV in Guangzhou, China. In addition, the clinical characteristics of hospitalized children infected with different subtype of HRV was investigated. METHODS: Hospitalized children aged < 14 years old with acute respiratory tract infections were enrolled from August 2018 to December 2019. HRV was screened for by a real-time reverse-transcription PCR targeting the viral 5'UTR. RESULTS: HRV was detected in 6.41% of the 655 specimens. HRV infection was frequently observed in children under 2 years old (57.13%). HRV-A and HRV-C were detected in 18 (45%) and 22 (55%) specimens. All 40 HRV strains detected were classified into 29 genotypes. The molecular evolutionary rate of HRV-C was estimated to be 3.34 × 10-3 substitutions/site/year and was faster than HRV-A (7.79 × 10-4 substitutions/site/year). Children who experienced rhinorrhoea were more common in the HRV-C infection patients than HRV-A. The viral load was higher in HRV-C detection group than HRV-A detection group (p = 0.0148). The median peak symptom score was higher in patients with HRV-C infection as compared to HRV-A (p = 0.0543), even though the difference did not significance. CONCLUSION: This study revealed the molecular epidemiological characteristics of HRV in patients with respiratory infections in southern China. Children infected with HRV-C caused more severe disease characteristics than HRV-A, which might be connected with higher viral load in patients infected with HRV-C. These findings will provide valuable information for the pathogenic mechanism and treatment of HRV infection.

Viral Infection and Respiratory Exacerbation in Children: Results from a Local German Pediatric Exacerbation Cohort.

Respiratory viruses play an important role in asthma exacerbation, and early exposure can be involved in recurrent bronchitis and the development of asthma. The exact mechanism is not fully clarified, and pathogen-to-host interaction studies are warranted to identify biomarkers of exacerbation in the early phase. Only a limited number of international exacerbation cohorts were studied. Here, we have established a local pediatric exacerbation study in Germany consisting of children with asthma or chronic, recurrent bronchitis and analyzed the viriome within the nasopharyngeal swab specimens derived from the entire cohort (n = 141). Interestingly, 41% of exacerbated children had a positive test result for human rhinovirus (HRV)/human enterovirus (HEV), and 14% were positive for respiratory syncytial virus (RSV). HRV was particularly prevalent in asthmatics (56%), wheezers (50%), and atopic (66%) patients. Lymphocytes were decreased in asthmatics and in HRV-infected subjects, and patients allergic to house dust mites were more susceptible to HRV infection. Our study thus confirms HRV infection as a strong 'biomarker' of exacerbated asthma. Further longitudinal studies will show the clinical progress of those children with a history of an RSV or HRV infection. Vaccination strategies and novel treatment guidelines against HRV are urgently needed to protect those high-risk children from a serious course of disease.

Human rhinoviruses prevailed among children in the setting of wearing face masks in Shanghai, 2020.

BACKGROUND: Human rhinovirus (HRV) is the predominant etiological agent of the common cold in children and adults. A recent study showed that the inhibitory effect of face masks on viral shedding of HRV was less prominent than that on other respiratory viruses. Considering that most Chinese people have worn face masks in public area since the outbreak of coronavirus disease 2019, we aimed to find out whether HRV prevailed among children in 2020 and demonstrate the details of the epidemiological features of HRV under such a special circumstance. METHODS: We summarized the incidences of various respiratory virus infections in patients who visited the Children's Hospital of Fudan University during 2018-2020, and genotyped HRV positive nasopharyngeal specimens collected from 316 inpatients and 72 outpatients that visited the hospital in 2020. RESULTS: There was a major prevalence of HRV among children in the latter half of 2020, with a clear seasonality that HRV-As prevailed in summer while HRV-Cs in autumn. HRV-As were more prone to cause severe lower respiratory tract infections (LRTI), while HRV-Cs were closely associated with childhood wheezing. The predominant genotypes were A11, A28, A47, A82, A101, C40 and C43. Notably, A21, A82 and A101 took up larger proportions in severe cases than in non-severe cases. CONCLUSIONS: Our findings described a major prevalence of HRVs among children in 2020, which highlight the unique transmitting pattern of HRV and help to narrow the targets for antiviral strategies.

Antiviral efficacy of cerium oxide nanoparticles (preprint)

Nanomaterials have been proposed as good candidates for the elimination of viruses due to their multimodal mechanisms of action. Here, we tested the antiviral potential of cerium dioxide (CeO 2 ) nanoparticles which is largely unexplored.Two types of nano-CeO 2 particles with opposing surface charge, nano-CeO 2 (+) and nano-CeO 2 (-), were assessed for their capability to decrease the plaque forming units (PFU) of four enveloped and two non-enveloped viruses during 1 h exposure. Statistically significant antiviral activity of nano-CeO 2 towards enveloped coronavirus SARS-CoV-2 and influenza virus A/WSN/1933 was registered already at 20 mg Ce/l. Significant decrease in PFU of other two enveloped viruses, transmissible gastroenteritis virus TGEV and bacteriophage φ6 was evidenced at 200 mg Ce/l. For all the enveloped viruses the maximum reduction of PFU after 1 h exposure to nano-CeO 2 exceeded 2 logs, that has been considered as the lowest biologically meaningful activity in antiviral applications. For most of the enveloped viruses, 1 h exposure to nano-CeO 2 resulted in ≥ 4 log reduction in PFU. As expected, the sensitivity of non-enveloped viruses towards nano-CeO 2 was significantly lower than that of enveloped viruses. Until the highest tested concentration, 2000 mg Ce/l neither of the nano-CeO 2 showed an effect on picornavirus EMCV and only nano-CeO 2 (-) caused a slight non-monotonic response in MS2 bacteriophage.Parallel testing of antiviral activity of Ce 3+ ions and SiO 2 nanoparticles allows to conclude that nano-CeO 2 activity was due to neither released Ce 3+ ions nor nonspecific effects of any nanosized particulate. Interestingly, we did not evidence any significant antiviral activity of Ag nanoparticles at 1 h exposure. This result referred to notably higher antiviral activity of nano-CeO 2 compared with nanosilver that has been generally considered as active against viruses. Although exhibiting antiviral effects, the antibacterial activity of nano-CeO 2 was very low. These results along with non-existent cytotoxicity nano-CeO 2 allow us to propose nano-CeO 2 for specific antiviral applications.

Hospitalized Children With Common Human Coronavirus Clinical Impact of Codetected Respiratory Syncytial Virus and Rhinovirus.

BACKGROUND: The clinical impact of common human coronavirus (cHCoV) remains unclear. We studied the clinical manifestations of pediatric cHCoV infections and the possible modifying effects of codetected human rhinovirus (RV) and respiratory syncytial virus (RSV). METHODS: We used data from an 11-year-long prospective study of hospitalized children with community-acquired respiratory tract infections. Nasopharyngeal aspirates were analyzed with real-time polymerase chain reaction assay for cHCoV OC43, NL63, HKU1 and 229E, and 15 other respiratory viruses. We assessed disease severity based on the clinical factors hospitalization length, oxygen requirement, other respiratory support and supplementary fluids. RESULTS: cHCoV was detected in 341 (8%) of 4312 children. Among 104 children with single cHCoV detections, 58 (56%) had lower respiratory tract infection (LRTI) and 20 (19%) developed severe disease. The proportion with severe disease was lower among single cHCoV detections compared with single RSV detections (338 of 870; 39%), but similar to single RV detections (136 of 987; 14%). Compared with single cHCoV, codetected cHCoV-RSV was more often associated with LRTI (86 of 89; 97%) and severe disease (adjusted odds ratio, 3.3; 95% confidence interval: 1.6-6.7). LRTI was more frequent in codetected cHCoV-RV (52 of 68; 76%) than single cHCoV, but the risk of severe disease was lower (adjusted odds ratios, 0.3; 95% confidence interval: 0.1-1.0). CONCLUSIONS: cHCoV was associated with severe LRTI in hospitalized children. Viral codetections were present in two-thirds. Codetections of cHCoV-RV were associated with lower proportions of severe disease, suggesting a modifying effect of RV on HCoV.