The role of viral co-infections in the severity of acute respiratory infections among children infected with respiratory syncytial virus (RSV): A systematic review and meta-analysis

Sequencing and characterization of human bocavirus genomes from patients diagnosed in Southern France between 2017 and 2022

The diversity and evolution of the genomes of human bocavirus (HBoV), which causes respiratory diseases, have been scarcely studied. Here, we aimed to obtain and characterize HBoV genomes from patients's nasopharyngeal samples collected between 2017 and 2022 period (5 years and 7 months). Next-generation sequencing (NGS) used Illumina technology after having implemented using GEMI an in-house multiplex PCR amplification strategy. Genomes were assembled and analyzed with CLC Genomics, Mafft, BioEdit, MeV, Nextclade, MEGA, and iTol. A total of 213 genomes were obtained. Phylogeny classified them all as of Bocavirus 1 (HBoV1) species. Five HBoV1 genotypic clusters determined by hierarchical clustering analysis of 27 variable genome positions were scattered over the study period although with differences in yearly prevalence. A total of 167 amino acid substitutions were detected. Besides, coinfection was observed for 52% of the samples, rhinoviruses then adenoviruses (HAdVs) being the most common viruses. Principal component analysis showed that HBoV1 genotypic cluster α tended to be correlated with HAdV co-infection. Subsequent HAdV typing for HBoV1-positive samples and negative controls demonstrated that HAdVC species predominated but HAdVB was that significantly HBoV1-associated. Overall, we described here the first HBoV1 genomes sequenced for France. HBoV1 and HAdVB association deserves further investigation.

Epidemiology of respiratory syncytial virus in hospitalized children over a 9-year period and preventive strategy impact

Background: Respiratory Syncytial Virus (RSV) is the primary cause of respiratory infections and hospitalizations in young children globally, leading to substantial disease burden and mortality. The aim of the present study was to review and provide updates on how the SARS-CoV-2 pandemic have significantly influenced RSV epidemiology on hospitalized children due to RSV infection. A potential impact of the available preventive strategies on the same population were provided. Methods: All children aged 0-6 years hospitalized at Meyer Children's Hospital IRCCS for RSV infection from September 2014 to March 2023 were retrospectively recorded. Seasonal trends before and after SARS-CoV-2 pandemic, age distribution, ICU admission and co-infections, comorbidities and prematurity were retrieved. Predictions on the number of hospitalizations avoided by the deployment of different preventive strategies were provided. Results: A total of 1,262 children with RSV infection were included in the study. The 70% of them had less than 1 year-of-age at the moment of hospitalization and almost 50% less than 3 months. In the post-pandemic seasons, a 317% increase in the number of hospitalizations was recorded with a significant increase in older children compared to the pre-pandemic seasons. ICU support was required for 22% of children, the majority of whom were under 3 months of age. Almost 16% of hospitalized children were born preterm and only 27% of hospitalized children had prior comorbidities. The rate of comorbidities among RSV hospitalized children increased with age. Nirsevimab prophylaxis could have prevented more than 46% of hospitalizations in this cohort. A preventive strategy addressing also children aged 7 months to 6 years of age with co-existing comorbidities would increase that rate above 57%. Discussion: The identification of RSV hospitalization-related features is informing the decision-maker for the deployment of the wisest preventive approach on a population scale.

Epidemiology of Respiratory Viruses in Korean Children Before and After the COVID-19 Pandemic: A Prospective Study From National Surveillance System

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic led to a decrease in the seasonal incidence of many respiratory viruses worldwide due to the impact of nonpharmaceutical interventions (NPIs). However, as NPI measures were relaxed, respiratory viral infections re-emerged. We aimed to characterize the epidemiology of respiratory viruses in Korean children during post-COVID-19 pandemic years compared to that before the pandemic.

METHODS

A nationwide prospective ongoing surveillance study has been conducted for detection of respiratory viruses between January 2017 and June 2023. We included data on adenovirus (AdV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus (HMPV), human rhinovirus (HRV), influenza virus (IFV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV), which were detected in children and adolescents younger than 20 years. We analyzed the weekly detection frequency of individual viruses and the age distribution of the affected children. The study period was divided into prepandemic (2017-2019) and postpandemic (2021-2023) periods.

RESULTS

A total of 19,589 and 14,068 samples were collected in the pre- and postpandemic periods, respectively. The overall detection rate of any virus throughout the study period was 63.1%, with the lowest occurring in the 2nd half of 2020 (50.6%) and the highest occurring in the 2nd half of 2021 (72.3%). Enveloped viruses (HCoV, HMPV, IFV, PIV, and RSV) almost disappeared, but nonenveloped viruses (AdV, HBoV, and HRV) were detected even during the peak of the COVID-19 pandemic. The codetection rate increased from 15.0% prepandemic to 19.1% postpandemic (P < 0.001). During the postpandemic period, a large out-of-season PIV and HMPV epidemic occurred, but the usual seasonality began to be restored in 2023. The mean age of children with each virus detected in 2023 was significantly greater than that in prepandemic years (P = 0.003 and 0.007 for AdV and HCoV, respectively; P < 0.001 for others). The mean age of children with IFV increased in 2022 (11.1 ± 5.2 years) from prepandemic years (7.9 ± 4.6 years) but decreased to 8.7 ± 4.1 years in 2023.

CONCLUSION

With the relaxation of NPI measures, several seasonal respiratory viruses cocirculated with unusual seasonal epidemic patterns and were associated with increasing age of infected children.

Respiratory syncytial virus in pediatric patients admitted to a tertiary center in Amman: clinical characteristics, and age-related patterns

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of acute lower respiratory tract infections, particularly in infants and young children during winter. We aimed to study the demographics and clinical characteristics of RSV infections and age-related patterns.

METHODS

This retrospective study evaluated pediatric respiratory syncytial virus (RSV) infections conducted in Jordan from September 2021 to March 2022. Patients under the age of five who had viral polymerase chain reaction results showing RSV infection from nasopharyngeal aspiration were included. In addition, demographic information, medical history, and clinical data were gathered. These included comorbidities, outcomes, length of stay, ICU hospitalization, use of antibiotics, and oxygen supplementation.

RESULTS

A total of 199 patients were included. Most patients were males (56.8%) and less than one year (43.7%). Children aged between 1 and 2 years presented with more shortness of breath (90.1%) than infants and children more than two years (66.7% and 87%, respectively) (p < 0.001). Older children (> 2 years) were significantly more likely to use antibiotics and have ICU admission than younger children ≤ 2 years (p = 0.045 and 0.018, respectively). There was no relationship between age groups, recurrent hospitalization, previous RSV infection, oxygen therapy, coinfection, and hospitalization duration. The respiratory rate was higher among patients with co-infection (p = 0.031).

CONCLUSION

The current study provides information on the demographics and clinical characteristics of RSV infections. These findings contribute to a nuanced understanding of RSV infections in the specified population, emphasizing age-specific variations and clinical implications for better management strategies.

Respiratory Viral Coinfections: Insights into Epidemiology, Immune Response, Pathology, and Clinical Outcomes

Respiratory viral coinfections are a global public health threat that poses an economic burden on individuals, families, and healthcare infrastructure. Viruses may coinfect and interact synergistically or antagonistically, or their coinfection may not affect their replication rate. These interactions are specific to different virus combinations, which underlines the importance of understanding the mechanisms behind these differential viral interactions and the need for novel diagnostic methods to accurately identify multiple viruses causing a disease in a patient to avoid misdiagnosis. This review examines epidemiological patterns, pathology manifestations, and the immune response modulation of different respiratory viral combinations that occur during coinfections using different experimental models to better understand the dynamics respiratory viral coinfection takes in driving disease outcomes and severity, which is crucial to guide the development of prevention and treatment strategies.

Changes in the global hospitalisation burden of respiratory syncytial virus in young children during the COVID-19 pandemic: a systematic analysis

BACKGROUND

The COVID-19 pandemic is reported to have affected the epidemiology of respiratory syncytial virus (RSV), which could have important implications for RSV prevention and control strategies. We aimed to assess the hospitalisation burden of RSV-associated acute lower respiratory infection (ALRI) in children younger than 5 years during the pandemic period and the possible changes in RSV epidemiology from a global perspective.

METHODS

We conducted a systematic literature search for studies published between Jan 1, 2020, and June 30, 2022, in MEDLINE, Embase, Global Health, Web of Science, the WHO COVID-19 Research Database, CINAHL, LILACS, OpenGrey, CNKI, WanFang, and CqVip. We included unpublished data on RSV epidemiology shared by international collaborators. Eligible studies reported data on at least one of the following measures for children (aged <5 years) hospitalised with RSV-associated ALRI: hospital admission rates, in-hospital case fatality ratio, and the proportion of hospitalised children requiring supplemental oxygen or requiring mechanical ventilation or admission to intensive care. We used a generalised linear mixed-effects model for data synthesis to measure the changes in the incidence, age distribution, and disease severity of children hospitalised with RSV-associated ALRI during the pandemic, compared with the year 2019.

FINDINGS

We included 61 studies from 19 countries, of which 14 (23%) studies were from the published literature (4052 identified records) and 47 (77%) were from unpublished datasets. Most (51 [84%]) studies were from high-income countries; nine (15%) were from upper-middle-income countries, one (2%) was from a lower-middle-income country (Kenya), and none were from a low-income country. 15 studies contributed to the estimates of hospitalisation rate and 57 studies contributed to the severity analyses. Compared with 2019, the rates of RSV-associated ALRI hospitalisation in all children (aged 0-60 months) in 2020 decreased by 79·7% (325 000 cases vs 66 000 cases) in high-income countries, 13·8% (581 000 cases vs 501 000 cases) in upper-middle-income countries, and 42·3% (1 378 000 cases vs 795 000 cases) in Kenya. In high-income countries, annualised rates started to rise in 2021, and by March, 2022, had returned to a level similar to 2019 (6·0 cases per 1000 children [95% uncertainty interval 5·4-6·8] in April, 2021, to March, 2022, vs 5·0 cases per 1000 children [3·6-6·8] in 2019). By contrast, in middle-income countries, rates remained lower in the latest period with data available than in 2019 (for upper-middle-income countries, 2·1 cases [0·7-6·1] in April, 2021, to March, 2022, vs 3·4 [1·2-9·7] in 2019; for Kenya, 2·2 cases [1·8-2·7] in 2021 vs 4·1 [3·5-4·7] in 2019). Across all time periods and income regions, hospitalisation rates peaked in younger infants (aged 0 to <3 months) and decreased with increasing age. A significantly higher proportion of children aged 12-24 months were hospitalised with RSV-associated ALRI in high-income and upper-middle-income countries during the pandemic years than in 2019, with odds ratios ranging from 1·30 (95% uncertainty interval 1·07-1·59) to 2·05 (1·66-2·54). No consistent changes in disease severity were observed.

INTERPRETATION

The hospitalisation burden of RSV-associated ALRI in children younger than 5 years was significantly reduced during the first year of the COVID-19 pandemic. The rebound in hospitalisation rates to pre-pandemic rates observed in the high-income region but not in the middle-income region by March, 2022, suggests a persistent negative impact of the pandemic on health-care systems and health-care access in the middle-income region. RSV surveillance needs to be established (or re-established) to monitor changes in RSV epidemiology, particularly in low-income and lower-middle-income countries.

FUNDING

EU Innovative Medicines Initiative Preparing for RSV Immunisation and Surveillance in Europe (PROMISE), Bill & Melinda Gates Foundation, and WHO.

Respiratory syncytial virus: A new era

Respiratory syncytial virus (RSV) is a major public health problem that has undergone significant changes in recent years. First of all, it has become easier to diagnose with highly reliable and rapidly available confirmatory tests. This has led to a better understanding of its epidemiology and RSV has gone from being a disease of the pediatric age group, severe only in infants and immunosuppressed children, to being a common disease in people of all ages, particularly important in patients of advanced age or with immunosuppressive diseases. Recent therapeutic and prophylactic advances, both with long-lasting monoclonal antibodies and vaccines, are another reason for satisfaction. For these reasons, the COVID and Emerging Pathogens Committee of the Illustrious Official College of Physicians of Madrid (ICOMEM) has considered it pertinent to review this subject in the light of new knowledge and new resources for dealing with this infection. We have formulated a series of questions that we believe will be of interest not only to members of the College but also to any non-expert in this subject, with a particular focus on the situation of RSV infection in Spain.

The risk of hospitalisation from RSV is not increased by co-infection in children under 24-months-of-age

The recent pandemic prompted renewed interest in paediatric respiratory infections, including whether co-infections - particularly with RSV - have an adverse prognostic impact. We evaluated the charts of all children presenting with respiratory symptoms to our unit between October 2022 and April 2023, each of whom was subjected to a multiplex PCR assay to detect eight viral targets and one bacterial target and examine the relationships between mono- and co-infections and hospitalization outcomes. We observed that younger age and RSV infection were both associated with the need for hospitalisation and the duration of hospitalisation after adjusting for confounders. Co-infection was, however, not associated with these outcomes.   Conclusion: This real-world data add to a growing consensus that RSV increases the risk of hospitalisation, while other co-infections, except for co-infection with SARS-CoV-2, do not. Given the timeframe over which our study was conducted, only a few children had SARS-CoV-2 co-infection, so we could not confirm any significant effect from this interaction. What is Known: • RSV increases the risk of hospitalisation and the need tor ventilatory support, especially in very young children. What is New: • Younger age and RSV infection were both associated with the need for hospitalisation and the duration of hospitalisation after adjusting for confounders. • Co-infection was, however, not associated with these outcomes.

Targeted metagenomics reveals association between severity and pathogen co-detection in infants with respiratory syncytial virus

Respiratory syncytial virus (RSV) is the leading cause of hospitalisation for respiratory infection in young children. RSV disease severity is known to be age-dependent and highest in young infants, but other correlates of severity, particularly the presence of additional respiratory pathogens, are less well understood. In this study, nasopharyngeal swabs were collected from two cohorts of RSV-positive infants <12 months in Spain, the UK, and the Netherlands during 2017-20. We show, using targeted metagenomic sequencing of >100 pathogens, including all common respiratory viruses and bacteria, from samples collected from 433 infants, that burden of additional viruses is common (111/433, 26%) but only modestly correlates with RSV disease severity. In contrast, there is strong evidence in both cohorts and across age groups that presence of Haemophilus bacteria (194/433, 45%) is associated with higher severity, including much higher rates of hospitalisation (odds ratio 4.25, 95% CI 2.03-9.31). There is no evidence for association between higher severity and other detected bacteria, and no difference in severity between RSV genotypes. Our findings reveal the genomic diversity of additional pathogens during RSV infection in infants, and provide an evidence base for future causal investigations of the impact of co-infection on RSV disease severity.

A tale of two fusion proteins: understanding the metastability of human respiratory syncytial virus and metapneumovirus and implications for rational design of uncleaved prefusion-closed trimers

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) cause human respiratory diseases and are major targets for vaccine development. In this study, we designed uncleaved prefusion-closed (UFC) trimers for the fusion (F) proteins of both viruses by examining mutations critical to F metastability. For RSV, we assessed four previous prefusion F designs, including the first and second generations of DS-Cav1, SC-TM, and 847A. We then identified key mutations that can maintain prefusion F in a native-like, closed trimeric form (up to 76%) without introducing any interprotomer disulfide bond. For hMPV, we developed a stable UFC trimer with a truncated F2-F1 linkage and an interprotomer disulfide bond. Tens of UFC constructs were characterized by negative-stain electron microscopy (nsEM), x-ray crystallography (11 RSV-F and one hMPV-F structures), and antigenic profiling. Using an optimized RSV-F UFC trimer as bait, we identified three potent RSV neutralizing antibodies (NAbs) from a phage-displayed human antibody library, with a public NAb lineage targeting sites Ø and V and two cross-pneumovirus NAbs recognizing site III. In mouse immunization, rationally designed RSV-F and hMPV-F UFC trimers induced robust antibody responses with high neutralizing titers. Our study provides a foundation for future prefusion F-based RSV and hMPV vaccine development.

Substantial Burden of Nonmedically Attended RSV Infection in Healthy-Term Infants: An International Prospective Birth Cohort Study

BACKGROUND

During the first year of life, 1 in 4 infants develops a symptomatic respiratory syncytial virus (RSV) infection, yet only half seek medical attention. The current focus on medically attended RSV therefore underrepresents the true societal burden of RSV. We assessed the burden of nonmedically attended RSV infections and compared with medically attended RSV.

METHODS

We performed active RSV surveillance until the age of 1 year in a cohort (n = 993) nested within the Respiratory Syncytial Virus Consortium in EUrope (RESCEU) prospective birth cohort study enrolling healthy term-born infants in 5 European countries. Symptoms, medication use, wheezing, and impact on family life were analyzed.

RESULTS

For 97 of 120 (80.1%) nonmedically attended RSV episodes, sufficient data were available for analysis. In 50.5% (49/97), symptoms lasted ≥15 days. Parents reported impairment in usual daily activities in 59.8% (58/97) of episodes; worries, 75.3% (73/97); anxiety, 34.0% (33/97); and work absenteeism, 10.8% (10/93). Compared with medically attended RSV (n = 102, 9 hospital admissions), Respiratory Syncytial Virus NETwork (ReSViNET) severity scores were lower (3.5 vs 4.6, P < .001), whereas duration of respiratory symptoms and was comparable.

CONCLUSIONS

Even when medical attendance is not required, RSV infection poses a substantial burden to infants, families, and society. These findings are important for policy makers when considering the implementation of RSV immunization. Clinical Trials Registration. ClinicalTrials.gov (NCT03627572).

Beyond SARS-CoV-2: epidemiological surveillance of respiratory viruses in Jalisco, Mexico

Introduction

Respiratory viral infections represent a significant global health burden. Historically, influenza, rhinovirus, respiratory syncytial virus, and adenovirus have been the prevalent viruses; however, the landscape shifted with the widespread emergence of SARS-CoV-2. The aim of this study is to present a comprehensive epidemiological analysis of viral respiratory infections in Jalisco, Mexico.

Methods

Data encompassing individuals with flu-like symptoms from July 2021 to February 2023 was scrutinized for viral diagnosis through PCR multiplex. The effect of social mobility on the increase in respiratory viral diagnosis infection was considered to estimate its impact. Additionally, sequences of respiratory viruses stored in public databases were retrieved to ascertain the phylogenetic classification of previously reported viruses in Mexico.

Results

SARS-CoV-2 was the most detected virus (n = 5,703; 92.2%), followed by influenza (n = 479; 7.78%). These viruses were also found as the most common co-infection (n = 11; 50%), and for those with influenza, a higher incidence of severe disease was reported (n = 122; 90.4%; p < 0.001). Regarding comorbidities and unhealthy habits, smoking was found to be a risk factor for influenza infection but a protective factor for SARS-CoV-2 (OR = 2.62; IC 95%: 1.66-4.13; OR = 0.65; IC 95%: 0.45-0.94), respectively. Furthermore, our findings revealed a direct correlation between mobility and the prevalence of influenza infection (0.214; p < 0.001).

Discussion

The study presents evidence of respiratory virus reemergence and prevalence during the social reactivation, facilitating future preventive measures.

Respiratory syncytial virus disease morbidity in Australian infants aged 0 to 6 months: a systematic review with narrative synthesis

BACKGROUND

A significant proportion of the global respiratory syncytial virus (RSV) associated morbidity is accounted for by infants aged 0 to 6 months, who are particularly vulnerable to severe disease. In 2015, 44% of global hospitalisations in infants in this age group were secondary to RSV. The objective of this systematic review is to appraise and synthesise the local evidence of RSV infection morbidity among Australian infants aged 0 to 6 months and to assess the implications for future immunisation strategies.

METHODS

Electronic databases (Medline, Embase, Pubmed and Global Health) were searched for full-text articles published between 2000 and 2023 in English language. Studies that examined markers of RSV disease morbidity in infants aged 0 to 6 months in Australia who had laboratory confirmed RSV infection were eligible for inclusion. The outcomes of interest were incidence, prevalence, testing rate, positivity rate, mortality, emergency department visits, community health visits, hospitalisation, intensive care unit admission, supplementary oxygen use, mechanical ventilation, risk factors for disease severity and monoclonal antibody use.

RESULTS

The database search identified 469 studies. After removal of duplicates and full-text review, 17 articles were eligible for inclusion. This review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Synthesis without meta-analysis guidelines.

CONCLUSIONS

Qualitative analysis of the included studies showed that Australian infants aged 0 to 6 months have higher rates of RSV testing, positivity and incidence; and more likely to develop severe disease that requires hospitalisation, intensive care unit admission or respiratory support, compared to children and adults of all ages. Aboriginal and Torres Strait Islander infants aged 0 to 6 months demonstrated higher rates of RSV infection and hospitalisation, compared to non-Indigenous infants. Age-related trends persisted in geographic areas with varying seasonal transmission of RSV, and during the SARS-CoV-2 pandemic. Passive immunisation strategies targeting infants in their first 6 months of life, either via vaccination of pregnant women or administration of long-acting monoclonal antibody during infancy, could effectively reduce RSV disease burden in Australia.

Etiology of Acute Lower Respiratory Illness Hospitalizations Among Infants in 4 Countries

Background

Recent studies explored which pathogens drive the global burden of pneumonia hospitalizations among young children. However, the etiology of broader acute lower respiratory tract infections (ALRIs) remains unclear.

Methods

Using a multicountry study (Albania, Jordan, Nicaragua, and the Philippines) of hospitalized infants and non-ill community controls between 2015 and 2017, we assessed the prevalence and severity of viral infections and coinfections. We also estimated the proportion of ALRI hospitalizations caused by 21 respiratory pathogens identified via multiplex real-time reverse transcription polymerase chain reaction with bayesian nested partially latent class models.

Results

An overall 3632 hospitalized infants and 1068 non-ill community controls participated in the study and had specimens tested. Among hospitalized infants, 1743 (48.0%) met the ALRI case definition for the etiology analysis. After accounting for the prevalence in non-ill controls, respiratory syncytial virus (RSV) was responsible for the largest proportion of ALRI hospitalizations, although the magnitude varied across sites-ranging from 65.2% (95% credible interval, 46.3%-79.6%) in Albania to 34.9% (95% credible interval, 20.0%-49.0%) in the Philippines. While the fraction of ALRI hospitalizations caused by RSV decreased as age increased, it remained the greatest driver. After RSV, rhinovirus/enterovirus (range, 13.4%-27.1%) and human metapneumovirus (range, 6.3%-12.0%) were the next-highest contributors to ALRI hospitalizations.

Conclusions

We observed substantial numbers of ALRI hospitalizations, with RSV as the largest source, particularly in infants aged <3 months. This underscores the potential for vaccines and long-lasting monoclonal antibodies on the horizon to reduce the burden of ALRI in infants worldwide.

Respiratory syncytial virus in children: epidemiology and clinical impact post-COVID-19

PURPOSE OF REVIEW

Respiratory syncytial virus (RSV) remains a leading cause of mortality and morbidity worldwide. RSV seasonality was disrupted by COVID-19-associated nonpharmaceutical interventions (NPIs). We review RSV seasonality, molecular epidemiology, clinical manifestations, and community awareness to inform future prevention strategies.

RECENT FINDINGS

An initial reduction of RSV disease observed with NPIs, and subsequent global resurgence was associated with a collapse in genetic diversity. A lack of immunity is suggested to have contributed to the resurgence of RSV cases experienced post COVID-19. The median age of children admitted with RSV increased during the resurgence, likely secondary to the expanded cohort of RSV-immune naive children. The pandemic also played a role in increased community awareness, which can be utilized as part of a coordinated public health effort to introduce prevention strategies. Further education on signs and symptoms of RSV is still required.

SUMMARY

mAbs and maternal vaccines targeting RSV have the potential to reduce paediatric morbidity, however this new era of RSV prevention will require ongoing research to facilitate community awareness and engagement, and better respiratory surveillance. Tackling the global burden of RSV will require a coordinated effort and measures to ensure access and affordability of new prevention strategies.

Clinical Relevance of RSV and SARS-CoV-2 Coinfections in Infants and Young Children

We analyzed the frequency, clinical impact and severity of respiratory syncytial virus (RSV) and SARS-CoV-2 coinfections in a single pediatric center between March 2020 and January 2023. Compared to single RSV infections, RSV/SARS-CoV-2 coinfections were uncommon (2.1%), occurred more frequently during circulation of omicron, and were associated with increased disease severity as defined by longer hospitalization and increased need for high-flow nasal cannula.

Monocyte and neutrophil to lymphocyte ratios in hospitalized children with RSV bronchiolitis

OBJECTIVE

Acute bronchiolitis is the most common cause of hospitalization in young children. Data on monocyte-to-lymphocyte-ratio (MLR) and neutrophil-to-lymphocyte-ratio (NLR) as biomarkers are limited. We aim to evaluate these ratios in children hospitalized with respiratory syncytial virus (RSV) bronchiolitis and their value as biomarkers for severe clinical outcomes.

STUDY DESIGN

A single-center retrospective cohort study of children aged <2 years hospitalized due to RSV bronchiolitis, between January 2018 and March 2022, with a complete blood count upon admission. We divided the cohort into quartiles based on MLR and NLR values. We examined associations between quartiles and four clinical severity outcomes.

RESULTS

A total of 2038 children (median age: 4.4 months, IQR: 1.9-9.8) were included in the study. The median MLR and NLR values for quartiles 1-4 were 0.14, 0.22, 0.30, 0.47, and 0.37, 0.70, 1.16, 2.29, respectively. Children with higher MLR had higher hospitalization rates to the pediatric intensive care unit (PICU) (Q1 2.4%, Q4 9.4%, p < .001), extended hospital stays (Q1 19.4%, Q4 32%, p < .001), and lower minimal oxygen saturation (Q1 90%, Q4 87%, p < .001). Cut-off values of 0.34 for MLR and 0.67 for NLR optimally identified PICU admissions. In a model accounting for age and sex, the fourth MLR quartile had an RR of 3.4 (95% CI: 1.76-7.22) and successfully predicted PICU admissions (area under the curve = 0.73; 95% CI: 0.681-0.789).

CONCLUSIONS

MLR and NLR are potential biomarkers for identifying children with RSV bronchiolitis at a higher risk for severe outcomes, specifically PICU admission.

Epidemiology and associated factors for hospitalization related respiratory syncytial virus infection among children less than 5 years of age in Northern Thailand

BACKGROUND

Respiratory syncytial virus (RSV) is often the main problem in young children that require hospitalization. The objective of this study was to identify factors associated with RSV-related hospitalizations in young children less than five years old.

METHODOLOGY

A retrospective study was conducted for acute respiratory tract infection (ARTI) at a tertiary care hospital from January 2017 to December 2021 by using binary logistic regression analysis to detect the associated factors with RSV-related hospitalizations in children.

RESULTS

RSV-related hospitalization was detected in 293 of 410 (71.46 %) cases of RSV infection, most of which appeared in the rainy months of August to November. The most common symptoms and signs were 81.5 % rhinorrhea, 70.7 % cough, 68.5 % sore throat, 68.3 % sputum production, and 66.8 % fever. Factors associated with RSV-related hospitalization were age less than or equal to 2 years (aOR = 4.62, 95 % CI = 1.86-11.44), preterm birth (aOR = 2.61, 95 % CI = 1.05-6.10), patients with underlying disease (aOR = 3.06, 95 % CI = 1.21-10.34), and the presenting symptoms with sputum production (aOR = 16.49, 95 % CI = 3.80-71.55). Laboratory blood tests, low levels of hematocrit (aOR = 9.61, 95 % CI = 1.09-84.49) was the associated factor for hospitalization with RSV infection (p < 0.05).

CONCLUSIONS

Factors associated with RSV-related hospitalizations in children were age less than or equal to two years, preterm birth, underlying disease, symptoms of sputum production. The low level of hematocrit was also associated with RSV-related hospitalizations in these children.

Impact of public health measures and new introducing variants on Respiratory syncytial virus recrudescence in Taiwan during the COVID-19 pandemic

OBJECTIVES

Respiratory syncytial virus (RSV) causes clinically significant distress in children and adults. Non-pharmaceutical interventions against SARS-CoV-2 have affected the seasonal activity of common respiratory pathogens. This seems exceptionally true regarding RSV's seasonal circulation, hence we have investigated the changes in the epidemiology of RSV in Taiwan during the pandemic.

MATERIALS

A prospective surveillance of RSV among hospitalized children was carried out between 2020 and 2022 in central Taiwan. Of all PCR-detected RSV, genotype and evolutionary analysis were further investigated. Demographics and clinical features were compared between each outbreak.

RESULTS

Throughout the consecutive three years of the SARS-CoV-2 pandemic, RSV outbreaks took place in Taiwan first in 2020 and a second time in 2022. We enrolled 80 and 105 hospitalized child cases, in each surge respectively. The RSV G protein genomic analysis revealed that RSV ON1 and RSV BA9 were separately contributing to these two outbreaks, and evolutionary evidence indicated these RSV variants are new to Taiwan, with their own featured sets of mutations. Clinically, a shift in age of RSV infected children was found, but the clinical severity was not worse and remained independent of RSV genotype.

CONCLUSIONS

There were two delayed RSV surges after the relaxation of public measures during the pandemic in Taiwan, and both outbreaks were driven by new RSV genetic variants rather than cryptic circulation of the previous genetic clusters in Taiwan. These findings highlight the importance of continued surveillance on the trend and evolution of RSV after the COVID-19 pandemic.

Risk Factors Associated with Severe RSV Infection in Infants: What Is the Role of Viral Co-Infections?

The respiratory syncytial virus (RSV) represents the leading cause of viral lower respiratory tract infections (LRTI) in children worldwide and is associated with significant morbidity and mortality rates. The clinical picture of an RSV infection differs substantially between patients, and the role of viral co-infections is poorly investigated. During two consecutive winter seasons from October 2018 until February 2020, we prospectively included children up to 2 years old presenting with an acute LRTI, both ambulatory and hospitalized. We collected clinical data and tested nasopharyngeal secretions for a panel of 16 different respiratory viruses with multiplex RT-qPCR. Disease severity was assessed with traditional clinical parameters and scoring systems. A total of 120 patients were included, of which 91.7% were RSV positive; 42.5% of RSV-positive patients had a co-infection with at least one other respiratory virus. We found that patients suffering from a single RSV infection had higher pediatric intensive care unit (PICU) admission rates (OR = 5.9, 95% CI = 1.53 to 22.74), longer duration of hospitalization (IRR = 1.25, 95% CI = 1.03 to 1.52), and a higher Bronchiolitis Risk of Admission Score (BRAS) (IRR = 1.31, 95% CI = 1.02 to 1.70) compared to patients with RSV co-infections. No significant difference was found in saturation on admission, O2 need, or ReSViNET-score. In our cohort, patients with a single RSV infection had increased disease severity compared to patients with RSV co-infections. This suggests that the presence of viral co-infections might influence the course of RSV bronchiolitis, but heterogeneity and small sample size in our study prevents us from drawing strong conclusions. IMPORTANCE RSV is worldwide the leading cause of serious airway infections. Up to 90% of children will be infected by the age of 2. RSV symptoms are mostly mild and typically mimic a common cold in older children and adolescents, but younger children can develop severe lower respiratory tract disease, and currently it is unclear why certain children develop severe disease while others do not. In this study, we found that children with a single RSV infection had a higher disease severity compared to patients with viral co-infections, suggesting that the presence of a viral co-infection could influence the course of an RSV bronchiolitis. As preventive and therapeutic options for RSV-associated disease are currently limited, this finding could potentially guide physicians to decide which patients might benefit from current or future treatment options early in the course of disease, and therefore, warrants further investigation.

Metagenomic next-generation sequencing of bronchoalveolar lavage fluid from children with severe pneumonia in pediatric intensive care unit

Background

Severe pneumonia due to lower respiratory tract infections (LRTIs) is a significant cause of morbidity and mortality in children. Noninfectious respiratory syndromes resembling LRTIs can complicate the diagnosis and may also make targeted therapy difficult because of the difficulty of identifying LRTI pathogens. In the present study, a highly sensitive metagenomic next-generation sequencing (mNGS) approach was used to characterize the microbiome of bronchoalveolar lavage fluid (BALF) in children with severe lower pneumonia and identify pathogenic microorganisms that may cause severe pneumonia. The purpose of this study was to use mNGS to explore the potential microbiomes of children with severe pneumonia in a PICU.

Methods

We enrolled patients meeting diagnostic criteria for severe pneumonia admitted at PICU of the Children’s Hospital of Fudan University, China, from February 2018 to February 2020. In total, 126 BALF samples were collected, and mNGS was performed at the DNA and/or RNA level. The pathogenic microorganisms in BALF were identified and correlated with serological inflammatory indicators, lymphocyte subtypes, and clinical symptoms.

Results

mNGS of BALF identified potentially pathogenic bacteria in children with severe pneumonia in the PICU. An increased BALF bacterial diversity index was positively correlated with serum inflammatory indicators and lymphocyte subtypes. Children with severe pneumonia in the PICU had the potential for coinfection with viruses including Epstein–Barr virus, Cytomegalovirus, and Human betaherpesvirus 6B, the abundance of which was positively correlated with immunodeficiency and pneumonia severity, suggesting that the virus may be reactivated in children in the PICU. There was also the potential for coinfection with fungal pathogens including Pneumocystis jirovecii and Aspergillus fumigatus in children with severe pneumonia in the PICU, and an increase in potentially pathogenic eukaryotic diversity in BALF was positively associated with the occurrence of death and sepsis.

Conclusions

mNGS can be used for clinical microbiological testing of BALF samples from children in the PICU. Bacterial combined with viral or fungal infections may be present in the BALF of patients with severe pneumonia in the PICU. Viral or fungal infections are associated with greater disease severity and death.

Clinical characteristics and outcomes of children with single or co-detected rhinovirus-associated acute respiratory infection in Middle Tennessee

BACKGROUND

Rhinovirus (RV) is one of the most common etiologic agents of acute respiratory infection (ARI), which is a leading cause of morbidity and mortality in young children. The clinical significance of RV co-detection with other respiratory viruses, including respiratory syncytial virus (RSV), remains unclear. We aimed to compare the clinical characteristics and outcomes of children with ARI-associated RV-only detection and those with RV co-detection-with an emphasis on RV/RSV co-detection.

METHODS

We conducted a prospective viral surveillance study (11/2015-7/2016) in Nashville, Tennessee. Children < 18 years old who presented to the emergency department (ED) or were hospitalized with fever and/or respiratory symptoms of < 14 days duration were eligible if they resided in one of nine counties in Middle Tennessee. Demographics and clinical characteristics were collected by parental interviews and medical chart abstractions. Nasal and/or throat specimens were collected and tested for RV, RSV, metapneumovirus, adenovirus, parainfluenza 1-4, and influenza A-C using reverse transcription quantitative polymerase chain reaction assays. We compared the clinical characteristics and outcomes of children with RV-only detection and those with RV co-detection using Pearson's χ² test for categorical variables and the two-sample t-test with unequal variances for continuous variables.

RESULTS

Of 1250 children, 904 (72.3%) were virus-positive. RV was the most common virus (n = 406; 44.9%), followed by RSV (n = 207; 19.3%). Of 406 children with RV, 289 (71.2%) had RV-only detection, and 117 (28.8%) had RV co-detection. The most common virus co-detected with RV was RSV (n = 43; 36.8%). Children with RV co-detection were less likely than those with RV-only detection to be diagnosed with asthma or reactive airway disease both in the ED and in-hospital. We did not identify differences in hospitalization, intensive care unit admission, supplemental oxygen use, or length of stay between children with RV-only detection and those with RV co-detection.

CONCLUSION

We found no evidence that RV co-detection was associated with poorer outcomes. However, the clinical significance of RV co-detection is heterogeneous and varies by virus pair and age group. Future studies of RV co-detection should incorporate analyses of RV/non-RV pairs and include age as a key covariate of RV contribution to clinical manifestations and infection outcomes.

Clinical and Socioeconomic Burden of Respiratory Syncytial Virus in Iceland

INTRODUCTION

Respiratory syncytial virus (RSV), a very common pathogen, causes variable disease severity. In addition to considerable clinical burden on children, their families and healthcare facilities, RSV infections in children also carry significant direct and indirect socioeconomic burden.

METHODS

We analyzed data from 5 consecutive RSV seasons (2015-2020) and used virologically confirmed RSV infections and age <5 years as case definition. Clinical information was retrieved from electronic patient records. Costs were estimated by assuming an annual 30% attack rate and a combination of direct medical costs and calculations of societal costs of lost productivity.

RESULTS

A total of 716 children younger than 5 years of age had confirmed RSV infection of which 254 needed hospitalizations, most of whom were previously healthy. The median length of admission was 3.6 days and 13 patients needed intensive care. The hospital admission incidence rate was 2.5/1000 children/year, but 9.1 for children younger than 1 years of age. The total annual cost of RSV was estimated at €4.3 million, of which 10% was direct healthcare costs.

DISCUSSION

The clinical and socioeconomic disease burden of RSV in Iceland is substantial despite slightly lower hospital admission rates than other high-income countries. The prevention of RSV in young children, either through maternal or infant vaccination, has the potential to decrease both clinical and financial impact of the annual epidemics.

Respiratory syncytial virus among children hospitalized with severe acute respiratory infection in Kashmir, a temperate region in northern India

Background

Severe acute respiratory infections (SARI) are a leading cause of hospitalizations in children, especially due to viral pathogens. We studied the prevalence of respiratory viruses among children aged <5 years hospitalized with severe acute respiratory infections (SARI) in Kashmir, India.

Methods

We conducted a prospective observational study in two tertiary care hospitals from October 2013 to September 2014, systematically enrolling two children aged <5 years with SARI per day. We defined SARI as history of fever or measured fever (≥38°C) and cough with onset in the last 7 days requiring hospitalization for children aged 3-59 months and as physician-diagnosed acute lower respiratory infection for children aged <3 months. Trained study staff screened children within 24 hours of hospitalization for SARI and collected clinical data and nasopharyngeal swabs from enrolled participants. We tested for respiratory syncytial virus (RSV) A and B, influenza viruses, rhinoviruses (HRV)/enteroviruses, adenovirus (AdV), bocavirus (BoV), human metapneumovirus (hMPV) A and B, coronaviruses (OC43, NL65, C229E), and parainfluenza viruses (PIV) 1, 2, 3 and 4 using standardized duplex real-time polymerase chain reaction.

Results

Among 4548 respiratory illness admissions screened from October 2013 to September 2014, 1026 met the SARI case definition, and 412 were enrolled (ages = 5 days to 58 months; median = 12 months). Among enrolees, 256 (62%) were positive for any virus; RSV was the most commonly detected (n = 118, 29%) followed by HRV/enteroviruses (n = 88, 21%), PIVs (n = 31, 8%), influenza viruses (n = 18, 4%), BoV (n = 15, 4%), coronaviruses (n = 16, 4%), AdV (n = 14, 3%), and hMPV (n = 9, 2%). Fifty-four children had evidence of virus co-detection. Influenza-associated SARI was more common among children aged 1-5 years (14/18, 78%) while most RSV detections occurred in children <12 months (83/118, 70%). Of the RSV viruses typed (n = 116), the majority were type B (94, 80%). Phylogenetic analysis of G gene of RSV showed circulation of the BA9 genotype with 60bp nucleotide duplication.

Conclusions

Respiratory viruses, especially RSV, contributed to a substantial proportion of SARI hospitalizations among children <5 years in north India. These data can help guide clinicians on appropriate treatment and prevention strategies.

Incidence of respiratory syncytial virus lower respiratory tract infections during the first 2 years of life: A prospective study across diverse global settings

Background

The true burden of lower respiratory tract infections (LRTIs) due to respiratory syncytial virus (RSV) remains unclear. This study aimed to provide more robust, multinational data on RSV-LRTI incidence and burden in the first 2 years of life.

Methods

This prospective, observational cohort study was conducted in Argentina, Bangladesh, Canada, Finland, Honduras, South Africa, Thailand, and United States. Children were followed for 24 months from birth. Suspected LRTIs were detected via active (through regular contacts) and passive surveillance. RSV and other viruses were detected from nasopharyngeal swabs using PCR-based methods.

Results

Of 2401 children, 206 (8.6%) had 227 episodes of RSV-LRTI. Incidence rates (IRs) of first episode of RSV-LRTI were 7.35 (95% confidence interval [CI], 5.88–9.08), 5.50 (95% CI, 4.21–7.07), and 2.87 (95% CI, 2.18–3.70) cases/100 person-years in children aged 0–5, 6–11, and 12–23 months. IRs for RSV-LRTI, severe RSV-LRTI, and RSV hospitalization tended to be higher among 0–5 month olds and in lower-income settings. RSV was detected for 40% of LRTIs in 0–2 month olds and for approximately 20% of LRTIs in older children. Other viruses were codetected in 29.2% of RSV-positive nasopharyngeal swabs.

Conclusions

A substantial burden of RSV-LRTI was observed across diverse settings, impacting the youngest infants the most.

Clinical Trials Registration. NCT01995175.

Adenovirus can be a serious, life-threatening disease, even in previously healthy children

AIM

Adenovirus infections are exceedingly common in childhood. However, little is known of the clinical characteristics of children admitted with severe infection to the paediatric intensive care unit (PICU).

METHODS

Clinical data on children hospitalised with adenovirus infection between January 2005 and March 2020 were collected. We compared data between children hospitalised in the PICU and those who were not in a 1:2 ratio.

RESULTS

During the study period, 69 children with adenovirus infection were admitted to the PICU, representing 5% of all hospitalised children with adenovirus. Thirty-four (49%) were previously healthy children. Mortality occurred in 5 patients, and all had an underlying illness. Cidofovir was used in 21 children, including 11 who were previously healthy. No side effects were attributed to the treatment. During 2005-2014, viral co-infection rates were 42% in the PICU group and 11% in the control group (p = 0.002). However, during 2015-2020, when the viral panel became widespread in our institution, the rates of co-infection were similar in the two groups (32% and 34%, p = 1.0).

CONCLUSION

Our findings suggest that adenovirus may present as a serious, life-threatening disease even in previously healthy children.

A comparative analysis of the epidemiology of influenza and respiratory syncytial virus in Russia, 2013/14 to 2018/19

Background

Influenza and respiratory syncytial virus (RSV) are among the leading causes of lower respiratory tract infections worldwide. We conducted a comparative analysis of the age distribution and spatiotemporal epidemiology of influenza and RSV in Russia using sentinel surveillance data from 2013-14 to 2018-19 in six cities located in the western, central, and eastern regions of the country.

Methods

We calculated the positivity rate for influenza and RSV (by month, season, and overall) in each city, separately for patients seen at the primary and secondary care level (out-patients medical centres housing GP practices and infectious diseases hospitals, respectively). We compared the age distribution of patients infected with the different influenza virus (sub)types and RSV.

Results

A total of 17 551 respiratory specimens were included: the overall positivity rate was 13.5% for influenza and 4.4% for RSV. The A(H1N1)pdm09, A(H3N2) and B virus (sub)types caused 31.3%, 44.0% and, respectively, 24.7% of all influenza cases. The median age was older among influenza (15 years) than among RSV patients (3 years); differences across influenza virus (sub)types were seen only at the primary care level, with influenza A(H3N2) patients being significantly older than A(H1N1)pdm09 or B influenza patients. The timing of influenza epidemics was similar across cities, with the peak typically occurring in February or March. In contrast, the typical peak timing of RSV epidemics varied largely across cities, and the virus was often detected also in spring and summer months (unlike influenza).

Conclusions

Influenza and RSV epidemiology differed in many regards in Russia, especially in the timing of epidemics and the age distribution of infected subjects. Health policies aimed at containing the burden of diseases of viral respiratory infections in Russia should take these findings into account.

Risk factors associated with severe disease in respiratory syncytial virus infected children under 5 years of age

OBJECTIVE

To evaluate risk factors for severe disease in children under 59 months of age hospitalized with respiratory syncytial virus (RSV) infection.

STUDY DESIGN

We prospectively enrolled 1,096 cases of laboratory confirmed RSV infection during three consecutive RSV seasons in 2015-2018. Potential risk factors for severe disease were retrieved through patient questionnaires and linkage to national health registries. Need for respiratory support (invasive ventilation, bi-level positive airway pressure, or continuous positive airway pressure), and length of stay exceeding 72 h were used as measures of disease severity. Associations were investigated using multivariable logistic regression analyses. Multiple imputation was used to avoid bias and inference induced by missing data.

RESULTS

Risk factors associated with a need for respiratory support included age younger than 3 months of age [aOR: 6.73 (95% CI 2.71-16.7)], having siblings [aOR: 1.65 (95% CI 1.05-2.59)] and comorbidity [aOR: 2.40 (95% CI 1.35-4.24)]. The length of hospital stay >72 h was significantly associated with being younger than 3 months of age [aOR: 3.52 (95% CI 1.65-7.54)], having siblings [aOR: 1.45 (95% CI 1.01-2.08)], and comorbidity [aOR: 2.18 (95% CI 1.31-3.61)]. Sub-group analysis of children younger than 6 months of age confirmed the association between both young age and having siblings and the need for respiratory support.

CONCLUSION

In a large cohort of children <59 months hospitalized with RSV infection, young age, comorbidity, and having siblings were associated with more severe disease.

Role of age and birth month in infants hospitalized with RSV-confirmed disease in the Valencia Region, Spain

Background

RSV is the leading cause of hospital admissions in infants and the principal cause of bronchiolitis in young children. There is a lack of granular data on RSV‐associated hospitalization per season using laboratory confirmed results. Our current study addresses this issue and intends to fill this gap.

Methods

The study was conducted from 2014 through 2018, in 4 to 10 hospitals in the Valencia Region, Spain. Infants included in this study were admitted in hospital through the Emergency Department with a respiratory complaint and tested by RT‐PCR for RSV in a central laboratory.

Results

Incidence rates of RSV‐associated hospitalization varied by season and hospital. Overall, the highest incidence rates were observed in 2017/2018. RSV‐associated hospitalization was highest in infants below 3 months of age and in those born before or at the beginning of the RSV season. Almost 54% of total infants hospitalized with laboratory confirmed RSV were found to be born outside the season, from April to October. The RSV positivity rate by ICD‐10 discharged codes varied by season and age with results from 48% to 57% among LRI (J09‐J22).

Conclusion

The study was instrumental in bringing forth the time unpredictability of RSV epidemics, the critical impact of age, and the comparable distribution of RSV‐associated hospitalization in infants born on either side of the RSV season. These data could help in better characterization of the population that drives the healthcare burden and is crucial for the development of future immunization strategies, especially with upcoming vaccines in against RSV.

Broad Impact of Exchange Protein Directly Activated by cAMP 2 (EPAC2) on Respiratory Viral Infections

The recently discovered exchange protein directly activated by cAMP (EPAC), compared with protein kinase A (PKA), is a fairly new family of cAMP effectors. Soon after the discovery, EPAC has shown its significance in many diseases including its emerging role in infectious diseases. In a recent study, we demonstrated that EPAC, but not PKA, is a promising therapeutic target to regulate respiratory syncytial virus (RSV) replication and its associated inflammation. In mammals, there are two isoforms of EPAC-EPAC1 and EPAC2. Unlike other viruses, including Middle East respiratory syndrome coronavirus (MERS-CoV) and Ebola virus, which use EPAC1 to regulate viral replication, RSV uses EPAC2 to control its replication and associated cytokine/chemokine responses. To determine whether EPAC2 protein has a broad impact on other respiratory viral infections, we used an EPAC2-specific inhibitor, MAY0132, to examine the functions of EPAC2 in human metapneumovirus (HMPV) and adenovirus (AdV) infections. HMPV is a negative-sense single-stranded RNA virus belonging to the family Pneumoviridae, which also includes RSV, while AdV is a double-stranded DNA virus. Treatment with an EPAC1-specific inhibitor was also included to investigate the impact of EPAC1 on these two viruses. We found that the replication of HMPV, AdV, and RSV and the viral-induced immune mediators are significantly impaired by MAY0132, while an EPAC1-specific inhibitor, CE3F4, does not impact or slightly impacts, demonstrating that EPAC2 could serve as a novel common therapeutic target to control these viruses, all of which do not have effective treatment and prevention strategies.

Bacterial and Viral Coinfections with the Human Respiratory Syncytial Virus

The human respiratory syncytial virus (hRSV) is one of the leading causes of acute lower respiratory tract infections in children under five years old. Notably, hRSV infections can give way to pneumonia and predispose to other respiratory complications later in life, such as asthma. Even though the social and economic burden associated with hRSV infections is tremendous, there are no approved vaccines to date to prevent the disease caused by this pathogen. Recently, coinfections and superinfections have turned into an active field of study, and interactions between many viral and bacterial pathogens have been studied. hRSV is not an exception since polymicrobial infections involving this virus are common, especially when illness has evolved into pneumonia. Here, we review the epidemiology and recent findings regarding the main polymicrobial infections involving hRSV and several prevalent bacterial and viral respiratory pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Klebsiella pneumoniae, human rhinoviruses, influenza A virus, human metapneumovirus, and human parainfluenza viruses. As reports of most polymicrobial infections involving hRSV lack a molecular basis explaining the interaction between hRSV and these pathogens, we believe this review article can serve as a starting point to interesting and very much needed research in this area.

Sars-Cov2 Not Detected in a Pediatric Population With Acute Respiratory Infection in Primary Care in Central and Southern Italy From November 2019 to Early March 2020

Background: In December 2019, a novel coronavirus named SARS-CoV-2 started circulating in China and this led to a major epidemic in Northern Italy between February and May 2020. Young children (aged <5 years) seem to be less affected by this coronavirus disease (COVID-19) compared to adults, although there is very little information on the circulation of this new virus among children in Italy. We retrospectively tested nasopharyngeal swabs for SARS-CoV-2 in samples collected in young children between November, 2019 and March, 2020 in the context of the RSV ComNet study. Methods: Two networks of primary care pediatricians in Lazio (Central Italy) and Puglia (Southern Italy) collected nasopharyngeal swabs from children, aged <5 years, presenting with symptoms for an acute respiratory infection (ARI). The RSV ComNet study is a multicenter study implemented to estimate the burden of RSV in young children (aged <5 years) in the community. Swabs were sent to a central reference laboratory and tested for 14 respiratory viruses through RT-PCR. All collected samples were retrospectively tested for SARS-CoV-2 using RT-PCR (Istituto Superiore di Sanità protocol). Results: A total of 293 children with ARI were identified in the two participating networks. The highest number of cases were recruited in weeks 51/2019 and 3/2020. The majority of patients (57%) came from the Lazio region. All of the 293 samples tested negative for SARS-Cov2. Rhinovirus was the most frequently detected virus (44%), followed by RSV (41%) and influenza viruses (14%). Conclusions: Our study shows that in Lazio (a region of intermediate SARS-COV-2 incidence) and Puglia (a region of low incidence), the SARS-Cov2 virus did not circulate in a sample of ARI pediatric cases consulting primary care pediatricians between November 2019 and March 2020.

RSV and HMPV Infections in 3D Tissue Cultures: Mechanisms Involved in Virus-Host and Virus-Virus Interactions

Respiratory viral infections constitute a global public health concern. Among prevalent respiratory viruses, two pneumoviruses can be life-threatening in high-risk populations. In young children, they constitute the first cause of hospitalization due to severe lower respiratory tract diseases. A better understanding of their pathogenesis is still needed as there are no approved efficient anti-viral nor vaccine against pneumoviruses. We studied Respiratory Syncytial virus (RSV) and human Metapneumovirus (HMPV) in single and dual infections in three-dimensional cultures, a highly relevant model to study viral respiratory infections of the airway epithelium. Our investigation showed that HMPV is less pathogenic than RSV in this model. Compared to RSV, HMPV replicated less efficiently, induced a lower immune response, did not block cilia beating, and was more sensitive to IFNs. In dual infections, RSV-infected epithelia were less permissive to HMPV. By neutralizing IFNs in co-infection assays, we partially prevented HMPV inhibition by RSV and significantly increased the number of co-infected cells in the tissue. This suggests that interference in dual infection would be at least partly mediated by the host immune response. In summary, this work provides new insight regarding virus-host and virus-virus interactions of pneumoviruses in the airway epithelium. This could be helpful for the proper handling of at-risk patients.

The effectiveness and safety of Tanreqing Injection combined with ganciclovir on the treatment of respiratory syncytial virus pneumonia in children: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Based on the Theory of Traditional Chinese Medicine, this study systematically evaluated the effectiveness and safety of Chinese medicine preparation Tanreqing injection combined with ganciclovir on the treatment of respiratory syncytial virus pneumonia in children, and provided new ideas and methods for the treatment of respiratory syncytial virus pneumonia (RSVP) in children. At the same time, it also studies the effectiveness and safety of the combination of Chinese and Western medicine on the treatment of related diseases from the direction of evidence-based medicine.

METHODS

The relevant literature was searched by the computer in the electronic network databases, the retrieved databases include Chinese database and English database, English database includes PubMed, Cochrane Library, Embase and Web of Science. Chinese database includes: CNKI, SinoMed, WangFang Date, VIP and other networks electronic full-text database, conducting a randomized controlled trial of Tanreqing Injection combined with ganciclovir (study group) and ganciclovir alone (control group) on the treatment of RSVP in children and the retrieval time limit is set from the establishment of each database to July 1, 2020. According to the inclusion and exclusion criteria, the literature is independently searched and screened by 2 researchers, and conducting the full-text retrieval and evaluation of the research to be included, and extracting the information and checking it after reading the full-text; In case of disagreement, a third researcher will be invited to participate, and the decision is made after discussion by the 3 researchers. They were using the bias risk assessment tool provided by the Cochrane Handbook for Systematic Reviews of Interventions 3.0.2 to evaluate the selected literature. They were using RevMan 5.3 statistical software to conduct statistical analysis.

RESULTS

This study will be carried out in full accordance with the steps of systematic review as required in the Cochrane Handbook for Systematic Reviews of Interventions. All research results will be published publicly in international academic journals with peer review.

CONCLUSION

After the meta-analysis of Tanreqing injection combined with ganciclovir on the treatment of RSVP in children, this paper will give a scientific and objective judgment on the effectiveness and safety of the combined use of Chinese and Western medicine on the treatment of RSVP in children, to provide evidence-based medical evidence for the clinical application, effectiveness and safety of Chinese and Western medicine combined on the treatment of RSVP in children.

PROSPERO REGISTRATION NUMBER

OSF platform, registration number: j2bz5.

COVID-19 in Light of Seasonal Respiratory Infections

A wide diversity of zoonotic viruses that are capable of overcoming host range barriers facilitate the emergence of new potentially pandemic viruses in the human population. When faced with a new virus that is rapidly emerging in the human population, we have a limited knowledge base to work with. The pandemic invasion of the new SARS-CoV-2 virus in 2019 provided a unique possibility to quickly learn more about the pathogenesis of respiratory viruses. In this review, the impact of pandemics on the circulation of seasonal respiratory viruses is considered. The emergence of novel respiratory viruses has often been accompanied by the disappearance of existing circulating strains. Some issues arising from the spread of pandemic viruses and underlying the choices of a strategy to fight the coronavirus infection are discussed.