Rhinovirus/enterovirus RNA in tonsillar tissue of children with tonsillar disease

Is There an Association between Viral Infections and Risk for Pediatric Obstructive Sleep Apnea? A Systematic Review

(1) Background: Obstructive sleep apnea (OSA) affects approximately 1% to 5% of children. To date, the main pathophysiological factor is adenotonsillar tissue hypertrophy. As many respiratory viruses can persist in secondary lymphoepithelial organs after upper airway infection, the objective of this systematic review was to investigate the link between history of viral infections and the risk of pediatric OSA. (2) Methods: Corresponding references were searched electronically (PubMed [MEDLINE], Cochrane Library and Scopus) until 21 November 2022. Prospective or retrospective cohorts, evaluating the children suffering from OSA with history of viral infections and comparing them with children with no history of viral infections written in English, were included. Four independent reviewers selected studies, extracted data, and evaluated the risk of bias using ROBINS-I. (3) Results: Of 1027 potentially eligible articles, four studies (one retrospective, two prospective cohorts and one case-control) were included. (4) Conclusions: Exposure to lower airway infections may precede the diagnosis of pediatric OSA suggesting that respiratory viruses may play a mechanical role in the development of pediatric OSA. Further research is required to improve our understanding of the role of viral infections. Registration: PROSPERO CRD awaiting.

Increased Incidence of Obstructive Sleep Apnea in Hospitalized Children After Enterovirus Infection: A Nationwide Population-based Cohort Study

BACKGROUND

We report the first nationwide population-based cohort study using Taiwan's National Health Insurance Research Database on the association between enterovirus (EV) infection and the incidence of sleep disorders in a pediatric population.

METHODS

Two matched groups of children under 18 years of age were included in the analyses for nonapneic sleep disorder and obstructive sleep apnea (OSA). Among them, 316 subjects were diagnosed with OSA during the surveillance period, including 182 in the EV infection group and 134 in the non-EV infection group.

RESULTS

Hospitalization because of EV infection was associated with OSA after adjusting for age, sex, urbanization atopic disease and perinatal complications (adjusted hazard ratio: 1.62, 95% confidence interval: 1.18-2.21; P = 0.003). An additional factor significantly associated with sleep apnea was allergic rhinitis (hazard ratio: 4.82, 95% confidence interval: 3.45-6.72).

CONCLUSIONS

Children with severe EV infection (ie, requiring hospitalization) carry a significantly higher risk of developing OSA, particularly in those with allergic rhinitis. As pediatric obstructive sleep apnea is a treatable sleep disorder, we emphasize regular follow-up and early detection in children with EV infection.

Rhinovirus Viremia in Patients Hospitalized With Community-Acquired Pneumonia

Background

Rhinoviruses (RVs) are ubiquitous respiratory pathogens that often cause mild or subclinical infections. Molecular detection of RVs from the upper respiratory tract can be prolonged, complicating etiologic association in persons with severe lower respiratory tract infections. Little is known about RV viremia and its value as a diagnostic indicator in persons hospitalized with community-acquired pneumonia (CAP).

Methods

Sera from RV-positive children and adults hospitalized with CAP were tested for RV by real-time reverse-transcription polymerase chain reaction. Rhinovirus species and type were determined by partial genome sequencing.

Results

Overall, 57 of 570 (10%) RV-positive patients were viremic, and all were children aged <10 years (n = 57/375; 15.2%). Although RV-A was the most common RV species detected from respiratory specimens (48.8%), almost all viremias were RV-C (98.2%). Viremic patients had fewer codetected pathogens and were more likely to have chest retractions, wheezing, and a history of underlying asthma/reactive airway disease than patients without viremia.

Conclusions

More than 1 out of 7 RV-infected children aged <10 years hospitalized with CAP were viremic. In contrast with other RV species, RV-C infections were highly associated with viremia and were usually the only respiratory pathogen identified, suggesting that RV-C viremia may be an important diagnostic indicator in pediatric pneumonia.

Detection of common respiratory viruses in tonsillar tissue of children with obstructive sleep apnea

BACKGROUND

Early life viral infection is associated with neurogenic inflammation that is present in lymphoid tissues of the upper airway in children with obstructive sleep apnea (OSA). We hypothesized that viral genomic material is present in tonsils of children with OSA. Therefore, we examined tonsils for the presence of respiratory viruses' nucleic acids in children with OSA, and in children without OSA (undergoing surgery for recurrent throat infections (RI)).

METHODS

Tonsillar tissue from patients with OSA and RI was subjected to multiplex quantitative real time reverse transcription PCR (mqRTPCR), analyzed for the presence of common respiratory viruses' genetic material.

RESULTS

Fifty-six patients were included, of whom 34 had OSA (age (years ± S.D), 4.22 ± 1.14) and 22 with RI (4.35 ± 1.36). Respiratory viruses nucleic acids (24 detections) were observed in 17 (50%) OSA samples. In contrast, no virus was detected in RI samples (relative frequency P<0.0001). Viruses detected, based on frequency were Rhinovirus, Adenovirus, human metapneumovirus (hMPV), respiratory syncytial virus (RSV), and corona virus.

CONCLUSIONS

Respiratory viruses are detected in OSA hypertrophic tonsils, suggestive of their role in the evolution of tonsillar inflammation and hypertrophy. Early life viral infections may contribute to the pathogenesis of pediatric OSA.

Respiratory viruses are continuously detected in children with chronic tonsillitis throughout the year

OBJECTIVE

To evaluate the oscillations on the viral detection in adenotonsillar tissues from patients with chronic adenotonsillar diseases as an indicia of the presence of persistent viral infections or acute subclinical infections.

STUDY DESIGN

Cross-sectional prospective study.

SETTING

Tertiary hospital.

METHODS

The fluctuations of respiratory virus detection were compared to the major climatic variables during a two-year period using adenoids and palatine tonsils from 172 children with adenotonsillar hypertrophy and clinical evidence of obstructive sleep apnoea syndrome or recurrent adenotonsillitis, without symptoms of acute respiratory infection (ARI), by TaqMan real-time PCR.

RESULTS

The rate of detection of at least one respiratory virus in adenotonsillar tissue was 87%. The most frequently detected viruses were human adenovirus in 52.8%, human enterovirus in 47.2%, human rhinovirus in 33.8%, human bocavirus in 31.1%, human metapneumovirus in 18.3% and human respiratory syncytial virus in 17.2%. Although increased detection of human enterovirus occurred in summer/autumn months, and there were summer nadirs of human respiratory syncytial virus in both years of the study, there was no obvious viral seasonality in contrast to reports with ARI patients in many regions of the world.

CONCLUSION

Respiratory viruses are continuously highly detected during whole year, and without any clinical symptomatology, indicating that viral genome of some virus can persist in lymphoepithelial tissues of the upper respiratory tract.

Viral contamination of aerosol and surfaces through toilet use in health care and other settings

BACKGROUND

The airborne spreading of enteric viruses can occur through the aerosol and droplets produced by toilet flushing. These can contaminate the surrounding environment, but few data exist to estimate the risk of exposure and infection. For this reason environmental monitoring of air and selected surfaces was carried out in 2 toilets of an office building and in 3 toilets of a hospital before and after cleaning operations.

METHODS

To reveal the presence of norovirus, enterovirus, rhinovirus, human rotavirus, and Torque teno virus and to quantify human adenovirus and bacteria counts, molecular and cultural methods were used.

RESULTS

On the whole, viruses were detected on 78% of surfaces and in 81% of aerosol. Among the researched viruses, only human adenovirus and Torque teno virus were found in both surface and air samples. In several cases the same adenovirus strain was concurrently found in all matrices. Bacterial counts were unrelated to viral presence and cleaning did not seem to substantially reduce contamination.

CONCLUSIONS

The data collected in our study confirm that toilets are an important source of viral contamination, mainly in health care settings, where disinfection can have a crucial role in preventing virus spread.

Detection of respiratory viruses in nasopharyngeal swab and adenoid tissue from children submitted to adenoidectomy: pre- and postoperative analysis

Introduction The presence of respiratory viruses in lymphoid tissues of the nasopharynx and oropharynx and its impact on recurrent infections and hypertrophy of these tissues are not yet fully understood. Objective To identify and determine the prevalence of major respiratory viruses in nasopharyngeal secretions and adenoid tissue pre- and postoperatively of children undergoing adenoidectomy. Methods A prospective observational study was conducted in 36 patients under 12 years of age with upper airway lymphoid hypertrophy who were undergoing adenoidectomy, in which various respiratory viruses were investigated using real-time polymerase chain reaction in adenoid tissue and nasopharyngeal secretions collected preoperatively and 30 days postoperatively. Results At least 1 viral agent was isolated in any of the samples collected in 58.3% of children and 25.9% of total samples. Respiratory viruses were identified in 33.8% of preoperative nasopharyngeal specimens and in 19.8% of postoperative secretion. Of the 21 patients with positive results for any respiratory virus, 6 (28.6%) had more than 1 virus. Considering all 36 respiratory viruses found, the main agent isolated was rhinovirus (27.8%), followed by bocavirus (22.2%). Conclusion The virus found more frequently in all samples was rhinovirus. After removal of adenoid tissue, there was a decrease in the prevalence of the virus contained in nasopharyngeal secretion 30 days after surgery.

Tonsillar crypt epithelium is an important extra-central nervous system site for viral replication in EV71 encephalomyelitis

Enterovirus 71 (EV71; family Picornaviridae, species human Enterovirus A) usually causes hand, foot, and mouth disease, which may rarely be complicated by fatal encephalomyelitis. We investigated extra-central nervous system (extra-CNS) tissues capable of supporting EV71 infection and replication, and have correlated tissue infection with expression of putative viral entry receptors, scavenger receptor B2 (SCARB2), and P-selectin glycoprotein ligand-1 (PSGL-1). Formalin-fixed, paraffin-embedded CNS and extra-CNS tissues from seven autopsy cases were examined by IHC and in situ hybridization to evaluate viral antigens and RNA. Viral receptors were identified with IHC. In all seven cases, the CNS showed stereotypical distribution of inflammation and neuronal localization of viral antigens and RNA, confirming the clinical diagnosis of EV71 encephalomyelitis. In six cases in which tonsillar tissues were available, viral antigens and/or RNA were localized to squamous epithelium lining the tonsillar crypts. Tissues from the gastrointestinal tract, pancreas, mesenteric nodes, spleen, and skin were all negative for viral antigens/RNA. Our novel findings strongly suggest that tonsillar crypt squamous epithelium supports active viral replication and represents an important source of viral shedding that facilitates person-to-person transmission by both the fecal-oral or oral-oral routes. It may also be a portal for viral entry. A correlation between viral infection and SCARB2 expression appears to be more significant than for PSGL-1 expression.

Occurrence of human bocaviruses and parvovirus 4 in solid tissues

Human bocaviruses 1-4 (HBoV1-4) and parvovirus 4 (PARV4) are recently discovered human parvoviruses. HBoV1 is associated with respiratory infections of young children, while HBoV2-4 are enteric viruses. The clinical manifestations of PARV4 remain unknown. The objective of this study was to determine whether the DNAs of HBoV1-4 and PARV4 persist in human tissues long after primary infection. Biopsies of tonsillar tissue, skin, and synovia were examined for HBoV1-4 DNA and PARV4 DNA by PCR. Serum samples from the tissue donors were assayed for HBoV1 and PARV4 IgG and IgM antibodies. To obtain species-specific seroprevalences for HBoV1 and for HBoV2/3 combined, the sera were analyzed after virus-like particle (VLP) competition. While HBoV1 DNA was detected exclusively in the tonsillar tissues of 16/438 individuals (3.7%), all of them ≤8 years of age. HBoV2-4 and PARV4 DNAs were absent from all tissue types. HBoV1 IgG seroprevalence was 94.9%. No subject had HBoV1 or PARV4 IgM, nor did they have PARV4 IgG. The results indicate that HBoV1 DNA occurred in a small proportion of tonsils of young children after recent primary HBoV1 infection, but did not persist long in the other tissue types studied, unlike parvovirus B19 DNA. The results obtained by the PARV4 assays are in line with previous results on PARV4 epidemiology.

High rates of detection of respiratory viruses in tonsillar tissues from children with chronic adenotonsillar disease

Chronic tonsillar diseases are an important health problem, leading to large numbers of surgical procedures worldwide. Little is known about pathogenesis of these diseases. In order to investigate the role of respiratory viruses in chronic adenotonsillar diseases, we developed a cross-sectional study to determine the rates of viral detections of common respiratory viruses detected by TaqMan real time PCR (qPCR) in nasopharyngeal secretions, tonsillar tissues and peripheral blood from 121 children with chronic tonsillar diseases, without symptoms of acute respiratory infections. At least one respiratory virus was detected in 97.5% of patients. The viral co-infection rate was 69.5%. The most frequently detected viruses were human adenovirus in 47.1%, human enterovirus in 40.5%, human rhinovirus in 38%, human bocavirus in 29.8%, human metapneumovirus in 17.4% and human respiratory syncytial virus in 15.7%. Results of qPCR varied widely between sample sites: human adenovirus, human bocavirus and human enterovirus were predominantly detected in tissues, while human rhinovirus was more frequently detected in secretions. Rates of virus detection were remarkably high in tonsil tissues: over 85% in adenoids and close to 70% in palatine tonsils. In addition, overall virus detection rates were higher in more hypertrophic than in smaller adenoids (p = 0.05), and in the particular case of human enteroviruses, they were detected more frequently (p = 0.05) in larger palatine tonsils than in smaller ones. While persistence/latency of DNA viruses in tonsillar tissues has been documented, such is not the case of RNA viruses. Respiratory viruses are highly prevalent in adenoids and palatine tonsils of patients with chronic tonsillar diseases, and persistence of these viruses in tonsils may stimulate chronic inflammation and play a role in the pathogenesis of these diseases.

Decreasing incidence of adenotonsillar problems in Dutch general practice: real or artefact?

BACKGROUND

The incidence of hypertrophy and recurrent infections of the tonsils/adenoids appears to be decreasing in the Netherlands. It is uncertain whether this is a 'real' decrease in the incidence of disease or an 'artefact'.

AIM

To investigate possible causes of the decreasing incidence of adenotonsillar problems among Dutch children.

DESIGN OF STUDY

Observational.

SETTING

A nationally representative general practice database.

METHOD

Incidence rates were calculated over 2002-2005 among children aged 0-14 years. Multilevel Poisson regression analyses were used to examine the following possible causes of changing incidence rates: change in recording (more substitution codes), change in the demand for care (fewer visits to the GP), and change in the supply of care (fewer antibiotic prescriptions and referrals). Indications for a 'real' change in the incidence of disease were examined by calculating incidence rates of other clinical manifestations of microbial pathogens that may cause adenotonsillar problems.

RESULTS

The incidence rate decreased significantly (P = 0.017) from 3.0 to 1.3 per 1000 children per year. Correcting for demand for and supply of care led to a smaller decline in yearly incidence, from 2.9 to 1.7 per 1000 children per year (P = 0.105). No clearly similar trend was found in other clinical manifestations of viruses and bacteria that may cause adenotonsillar problems.

CONCLUSION

Part of the declining trend can be explained by a change in the demand for and supply of care, but no apparent causal clue emerged for the residual declining trend in the incidence of disease.

Newly identified human rhinoviruses: molecular methods heat up the cold viruses

Human rhinovirus (HRV) infections cause at least 70% of virus‐related wheezing exacerbations and cold and flu‐like illnesses. They are associated with otitis media, sinusitis and pneumonia. Annually, the economic impact of HRV infections costs billions in healthcare and lost productivity. Since 1987, 100 officially recognised HRV serotypes reside in two genetically distinct species; HRV A and HRV B, within the genus Enterovirus, family Picornaviridae. Sequencing of their ∼7kb genomes was finalised in 2009. Since 1999, many globally circulating, molecularly‐defined ‘strains’, perhaps equivalent to novel serotypes, have been discovered but remain uncharacterised. Many of these currently unculturable strains have been assigned to a proposed new species, HRV C although confusion exists over the membership of the species. There has not been sufficient sampling to ensure the identification of all strains and no consensus criteria exist to define whether clinical HRV detections are best described as a distinct strain or a closely related variant of a previously identified strain (or serotype). We cannot yet robustly identify patterns in the circulation of newly identified HRVs (niHRVs) or the full range of associated illnesses and more data are required. Many questions arise from this new found diversity: what drives the development of so many distinct viruses compared to other species of RNA viruses? What role does recombination play in generating this diversity? Are there species‐ or strain‐specific circulation patterns and clinical outcomes? Are divergent strains sensitive to existing capsid‐binding antivirals? This update reviews the findings that trigger these and other questions arising during the current cycle of intense rhinovirus discovery. Copyright © 2010 John Wiley & Sons, Ltd.

Human bocavirus and rhino-enteroviruses in childhood otitis media with effusion

Background

Viral respiratory infections play an important role in the pathogenesis of otitis media with effusion (OME) in children. The most common human rhinoviruses (HRVs) have been detected in middle ear effusions (MEE), but there is only limited data available about the closely related human enteroviruses (HEVs). The newly discovered human bocavirus (HBoV) has not, however, been identified in MEE of OME children.

Objectives

The aim of our study was to determine the presence of HBoV and HRV/HEV and the rate of coinfection in a set of MEE samples collected from OME children.

Study design

Seventy-five MEE samples from 54 children with no acute respiratory symptoms were studied with reverse transcription polymerase chain reaction (RT-PCR) for detection of HRV/HEV and quantitative PCR for detection of HBoV.

Results

Twenty-six (35%) of 75 MEE samples were positive for viral nucleic acid, 22 (29%) for HEV, 10 (13%) for HRV and 2 (3%) for HBoV. There was no statistically significant difference between mucoid and serous effusions in the rate of virus detection. Forty-three percent of bilateral cases showed a contra-lateral difference in viral finding.

Conclusions

Our results suggest that these common respiratory viruses can be associated with OME in children. Whether these viruses are causative etiologic factors of MEE persistence or merely remnants of previous infections is not known.

Epidemiology

The common cold is the result of an upper respiratory tract infection causing an acute syndrome characterised by a combination of non-specific symptoms, including sore throat, cough, fever, rhinorrhoea, malaise, headache, and myalgia. Respiratory viruses, alone or in combination, are the most common cause. The course f illness can be complicated by bacterial agents, causing pharyngitis or sinusitis, but the are a rare cause of cold and flu-like illnesses (CFLIs). Our understanding of CFLI epidemiology has been enhanced by molecular detection methods, particularly polymerase chain reaction (PCR) testing. PCR has not only improved detection of previously known viruses, but within the last decade has resulted in the detection of many divergent novel respiratory virus species. Human rhinovirus (HRV) infections cause nearly all CFLIs and they can be responsible for asthma and chronic obstructive pulmonary disease exacerbations. HRVs are co-detected with other respiratory viruses in statistically significant patterns, with HRVs occurring in the lowest proportion of co-detections, compared to most other respiratory viruses. Some recently identified rhinoviruses may populate an entirely new putative HRV species; HRV C. Further work is required to confirm a causal role for these newly identified viruses in CFLIs. The burden of illness associated with CFLIs is poorly documented, but where data are available, the impact of CFLIs is considerable. Individual infections, although they do not commonly result in more severe respiratory tract illness, are associated with substantial direct and indirect resource use. The product of frequency and burden for CFLIs is likely to be greater in magnitude than for any other respiratory syndrome, but further work is required to document this. Our understanding of the viral causes of CLFIs, although incomplete, has improved in recent years. Documenting burden is also an important step in progress towards improved control and management of these illnesses.

Human rhinoviruses: the cold wars resume

BACKGROUND

Human rhinoviruses (HRVs) are the most common cause of viral illness worldwide but today, less than half the strains have been sequenced and only a handful examined structurally. This viral super-group, known for decades, has still to face the full force of a molecular biology onslaught. However, newly identified viruses (NIVs) including human metapneumovirus and bocavirus and emergent viruses including SARS-CoV have already been exhaustively scrutinized. The clinical impact of most respiratory NIVs is attributable to one or two major strains but there are 100+ distinct HRVs and, because we have never sought them independently, we must arbitrarily divide the literature's clinical impact findings among them. Early findings from infection studies and use of inefficient detection methods have shaped the way we think of 'common cold' viruses today.

OBJECTIVES

To review past HRV-related studies in order to put recent HRV discoveries into context.

RESULTS

HRV infections result in undue antibiotic prescriptions, sizable healthcare-related expenditure and exacerbation of expiratory wheezing associated with hospital admission.

CONCLUSION

The finding of many divergent and previously unrecognized HRV strains has drawn attention and resources back to the most widespread and frequent infectious agent of humans; providing us the chance to seize the advantage in a decades-long cold war.

Respiratory viruses in laryngeal croup of young children

OBJECTIVES

To determine the viral cause of laryngeal croup by use of highly sensitive methods, and including recently recognized viruses in the analysis.

STUDY DESIGN

One hundred forty-four consecutive children with hoarse voice and inspiratory stridor attending the emergency department were enrolled. Age- and season-matched children presenting with a wheezing illness served as control subjects (n = 76). Nasopharyngeal swabs were analyzed by polymerase chain reaction for rhinovirus and enterovirus, coronavirus, respiratory syncytial virus (RSV), parainfluenza virus (PIV), influenza A and B virus, human bocavirus, human metapneumovirus, adenovirus, and Mycoplasma pneumoniae.

RESULTS

Virus infection was documented in 80% of patients with croup and 71% of control subjects. Children with croup had significantly more positive test results for PIV 1 and 2 (31% vs 4% and 6% vs 0%, respectively) and significantly fewer positive test results for RSV (15% vs 28%) than wheezing children. Rhinoviruses and enteroviruses were present equally in both groups (21% vs 25%). There was no significant difference in the frequency of influenza A virus or human bocavirus. Few subjects with adenovirus or M. pneumoniae were detected.

CONCLUSION

Acute laryngeal croup is most often associated with PIV, RSV, rhinovirus, and enterovirus. Rhinovirus and enterovirus appeared equally often in croup and in wheezing illness. During late fall, they were found in 39% and 40%, respectively, of the tested samples.

Comparison of results of detection of rhinovirus by PCR and viral culture in human nasal wash specimens from subjects with and without clinical symptoms of respiratory illness

Human rhinoviruses (HRV) cause acute upper respiratory illness. The frequency of HRV-associated illnesses appears greater when PCR assays are used to detect rhinoviruses. The present study performed PCR-based detection of HRV upon entry of subjects into respiratory syncytial virus and parainfluenza type 3 vaccine trials when subjects were symptom-free and upon subsequent development of clinical symptoms of respiratory illness during the trial. The background of HRV PCR positivity in symptom-free individuals (30/139 [22%]) was only slightly lower than in those with respiratory illness (28/77 [36%]). For subjects with multiple samples, it was estimated that HRV was detectable by PCR for approximately 100 days before, during, and after clinical symptoms were documented. PCR is a remarkably more sensitive method of detecting HRV than is tissue culture. The presence of HRV RNA may not always reflect an association with infectious virus production. The limited association of HRV RNA with illness suggests caution in assigning causality of HRV PCR positivity to clinical symptoms of respiratory illness.