Global burden and trends of respiratory syncytial virus infection across different age groups from 1990 to 2019: A systematic analysis of the Global Burden of Disease 2019 Study

Molecular epidemiology and phylogenetic analysis of human respiratory syncytial virus type B in Riyadh, Saudi Arabia

The human respiratory syncytial virus (HRSV), recently known as the human orthopneumovirus (HOPV), continues to generate new variants with the ability to cause recurrent infections. Data regarding HRSV-B evolution and genetic diversity in Riyadh, Saudi Arabia, are very limited. Therefore, the current study was designed to investigate the prevalence, genetic diversity, and evolution of HRSV-B. A total of 200 nasopharyngeal aspirate (NPA) samples from hospitalized children at King Khaled University Hospital were screened for the presence of HRSV-B. The second hypervariable region (2nd HVR) of the G gene from all 37 HRSV-B genotypes was used to study sequences and family trees. Of the 200 screened nasopharyngeal samples (NPAs), 16 (8%) were positive for HRSV-B, with a high incidence rate in the age group of 2 to 5 months. The analysis of the 2nd HVR region's sequence showed several differences, such as point mutations, different protein lengths, sequence gaps, duplication regions, and glycosylation sites. A total of 46-point mutations were reported, of which 29 changed their corresponding amino acid residues. N-linked glycosylation sites in Riyadh strains were 3, whereas O-linked glycosylation sites ranged from 22 to 32. Phylogenetic analysis revealed that Riyadh strains from the seasons 2019/20 and 2022/23 are grouped into the subclade BA-11. Other Riyadh strains from different previous seasons were clustered into different sub-genotypes (BA-9, -10, and -12). Seasonal surveillance and molecular evolution tracking of HRSV-B is essential for the early detection of viral genotypes that might cause severe illness consequences and widespread transmission.

Human Riboviruses: A Comprehensive Study

The urgency to understand the complex interactions between viruses, their animal reservoirs, and human populations has been necessitated by the continuous spread of zoonotic viral diseases as evidenced in epidemics and pandemics throughout human history. Riboviruses are involved in some of the most prevalent human diseases, responsible for causing epidemics and pandemics. These viruses have an animal origin and have been known to cross the inter-species barrier time and time again, eventually infecting human beings. Their evolution has been a long road to harbour important adaptations for increasing fitness, mutability and virulence; a result of natural selection and mutation pressure, making these viruses highly infectious and difficult to counter. Accumulating favourable mutations in the course, they imitate the GC content and codon usage patterns of the host for maximising the chances of infection. A myriad of viral and host factors determine the fate of specific viral infections, which may include virus protein and host receptor compatibility, host restriction factors and others. Thus, understanding the biology, transmission and molecular mechanisms of Riboviruses is essential for the development of effective antiviral treatments, vaccine development and strategies to prevent and control viral infections. Keeping these aspects in mind, this review aims to provide a holistic approach towards understanding Riboviruses.

Prevalence of Respiratory Syncytial Virus Infection in Hospitalized COPD Patients in Spain Between 2018-2022

BACKGROUND

Respiratory syncytial virus (RSV) infection is a common cause of hospital admission. The association between chronic obstructive pulmonary disease (COPD) exacerbation and RSV infection is not well studied.

OBJECTIVE

To analyze the hospitalizations of patients with COPD and RSV infection in Spain between 2018 and 2022.

METHODS

The data used were obtained from the Spanish Hospital Discharge Database. We selected subjects aged ≥40 years diagnosed with COPD, admitted to the hospital from 1 January 2018 to 31 December 2022. The COPD population that met the selection criteria was subdivided based on the presence of an ICD-10 code for RSV infection. To obtain comparable populations, for each subject with COPD and RSV infection, a subject without an RSV code was selected, with the COPD code in the same diagnostic position (1 to 20), as well as the same year of admission, sex, and age.

RESULTS

Among subjects aged ≥40 years, 1,429,288 were identified as having COPD, of whom 5673 also had RSV infection. The number of hospitalizations with COPD and RSV infection increased during the study period. The proportion of RSV infection among patients admitted for COPD increased significantly over time, from 0.32% in 2018 to 0.65% in 2022, p < 0.001. In-hospital mortality (IHM) increased over time, but the differences were not significant (6.23% in 2018 vs. 6.79% in 2022). Patients with COPD and RSV infection had, compared with those without RSV infection, a higher use of mechanical ventilation, both invasive (3.44% vs. 1.34%, p < 0.001) and noninvasive (8.09% vs. 4.51%, p < 0.001) and a higher proportion of intensive care unit (ICU) admission (7.21% vs. 3.9%, p < 0.001). After multivariate adjustment, a significant increase in IHM was found from 2018 to 2022 in subjects with and without RSV infection. The presence of RSV infection was associated with a higher mortality (OR 1.22; 95% CI 1.01-1.46).

CONCLUSIONS

The proportion of RSV infection among patients admitted for COPD increased significantly over time. Patients with COPD and RSV infection had, compared with those without RSV infection, a higher severity, a higher use of mechanical ventilation, and a higher proportion of ICU admission. The presence of RSV infection was associated with IHM. These results can help to identify patients at higher risk and make decisions to avoid the increased risk of hospitalization and mortality in this population.

Characteristics of the First Italian Older Adults Vaccinated with an Adjuvanted Respiratory Syncytial Virus (RSV) Vaccine

Background and Objectives: Three respiratory syncytial virus (RSV) vaccines have been recently made available for older adults. Understanding the principal characteristics of the first vaccine-takers can pave the way for a successful vaccination campaign. The objective of this study was to explore the sociodemographic and clinical characteristics of the first Italian users of an adjuvanted RSV vaccine and their attitudes towards RSV and vaccination. Materials and Methods: This cross-sectional study was conducted in 2024 in Liguria (Italy). Individuals aged ≥60 years with no contraindications to the adjuvanted vaccine RSVPreF3 OA were eligible. Following vaccination, subjects filled in a questionnaire, which comprised items on sociodemographic and clinical characteristics, attitudes towards RSV and RSV vaccination and a vaccination trust indicator (VTI). Results: A total of 453 vaccinees completed the survey. Their mean age was 74.9 ± 8.0 years, and 50.6% were males. Nine of ten (89.2%) individuals had ≥1 co-morbidity, of which cardiovascular conditions (70.4%), respiratory diseases (27.6%) and diabetes (18.5%) were the most common. Uptake of the routine vaccines was high: 91.2% and 98.7% received the 2023/2024 season influenza and ≥2 COVID-19 vaccines, respectively. The most common reasons for the current RSV vaccination were general practitioner advice (43.9%), followed by the willingness to be protected against (20.8%) and feelings of being at risk (16.6%) of RSV. The average VTI score was 91.5%, suggesting high trust in vaccines. More positive attitudes towards RSV vaccination were observed (p < 0.01) among subjects who received more COVID-19 vaccine doses, whose reasons for the current RSV vaccination were the willingness to be protected or to be in good health and the feeling of being at risk for RSV. Conclusions: The first Italian users of the novel RSVPreF3 OA vaccine were represented by high-risk individuals with a comparatively high prevalence of co-morbidities, high uptake of the seasonal respiratory vaccines and high trust in immunization.

Acceptance and safety of the RSV-preventive treatment of newborns with nirsevimab in the maternity department: a prospective longitudinal cohort study in France

Background

To evaluate the acceptance and safety of the treatment of newborns with nirsevimab (a long-acting monoclonal antibody designed to prevent respiratory syncytial virus infections) during the first season of implementation.

Methods

A longitudinal, prospective, single-centre cohort study was conducted from September 18th, 2023, to January 23rd, 2024 at Lille University Hospital (Lille, France). All newborns admitted to the hospital's maternity department during the study period and whose parents agreed to participate in the study were included. Parents were asked to state whether or not they agreed for their infant to receive nirsevimab. The occurrence of adverse events (AEs) 2 h after nirsevimab treatment and 7, 14 and 30 days after discharge was documented by the mother. The primary endpoint was the nirsevimab treatment acceptance rate. The secondary endpoints were the variables associated with the acceptance of nirsevimab, the reasons for accepting or refusing nirsevimab, and the treatment's real-life safety, relative to a non-treated control group of newborns.

Findings

Of the 1730 infants born in the hospital during the study period, 477 met all the inclusion criteria and were enrolled. The nirsevimab acceptance rate [95% confidence interval] was 91.6% [89.1%-94.2%]. In a multivariable analysis, the mother's age, lower parity and having a partner in work were significantly associated with nirsevimab acceptance. The most common reason for accepting treatment was "to protect my baby", and the most common reason for refusing treatment was the lack of long-term data on nirsevimab. The nirsevimab and control groups did not differ significantly in terms of the types and frequencies of AEs. At least one serious AE was reported for 9.4% of the infants in the nirsevimab group and for 10.3% in the control group. None of the serious AEs were considered to be related to nirsevimab treatment.

Interpretation

The nirsevimab acceptance rate for newborns in the maternity unit was high during the first season of implementation. The safety profile was very good, with no significant differences between the nirsevimab group and the control group.

Funding

None.

Molecular characterization of human respiratory syncytial virus strains circulating among hospitalized children in Jordan

BACKGROUND

Human Respiratory Syncytial Virus (HRSV) is a primary cause of severe pediatric respiratory infections, particularly in infants and young children, often resulting in hospitalization. The virus possesses a high degree of mutagenic potential, contributing to significant antigenic diversity, which complicates immune responses and poses challenges for vaccine development and disease management. This study was conducted in Jordan from 2022 to 2023 to epidemiologically determine the prevalence and molecular characteristics of RSV.

METHODS

A total of 288 nasopharyngeal (NP) swabs were collected from hospitalized children at Prince Hamza Hospital, Amman, Jordan. All samples were screened for common viral and bacterial respiratory pathogens using PCR. A partial segment of the G gene of RSV was amplified for molecular characterization and phylogenetic tree analysis.

RESULTS

Viral and/or bacterial infection was identified in 71.9% (207/288) of the tested specimens. Among these, 35 samples (12.2%, 35/288) tested positive for RSV. Specific subgroup PCR analysis identified (25, 71.4%) RSV-A, (4, 11.4%) RSV-B, and (6, 17.1%) could not be identified using our set of primers. Phylogenetic tree analysis revealed that RSV-A ON1 and RSV-B BA9 genotype strains predominate in Jordan. We observed multiple substitutions in our studied sample which would drive variation in the level of antigenicity and pathogenicity of RSV. Glycosylation sites identified were consistent with previously reported studies.

CONCLUSION

This study provides updated epidemiological data on the strains circulating in Amman, Jordan and their molecular characteristics. Continuous RSV surveillance informs vaccine development, guides public health interventions, and enables timely administration of prophylactic treatments, reducing the burden of RSV-related illness.

Respiratory Syncytial Virus: A WAidid Consensus Document on New Preventive Options

Background/Objectives: Respiratory syncytial virus (RSV) is a leading cause of respiratory infections, particularly affecting young infants, older adults, and individuals with comorbidities. Methods: This document, developed as a consensus by an international group of experts affiliated with the World Association of Infectious Diseases and Immunological Disorders (WAidid), focuses on recent advancements in RSV prevention, highlighting the introduction of monoclonal antibodies (mAbs) and vaccines. Results: Historically, RSV treatment options were limited to supportive care and the monoclonal antibody palivizumab, which required multiple doses. Recent innovations have led to the development of long-acting mAbs, such as nirsevimab, which provide season-long protection with a single dose. Nirsevimab has shown high efficacy in preventing severe RSV-related lower respiratory tract infections (LRTIs) in infants, reducing hospitalizations and ICU admissions. Additionally, new vaccines, such as RSVpreF and RSVpreF3, target older adults and have demonstrated significant efficacy in preventing LRTIs in clinical trials. Maternal vaccination strategies also show promise in providing passive immunity to newborns, protecting them during the most vulnerable early months of life. This document further discusses the global burden of RSV, its economic impact, and the challenges of implementing these preventative strategies in different healthcare settings. Conclusions: The evidence supports the integration of both passive (mAbs) and active (vaccines) immunization approaches as effective tools to mitigate the public health impact of RSV. The combined use of these interventions could substantially reduce RSV-related morbidity and mortality across various age groups and populations, emphasizing the importance of widespread immunization efforts.

Retrospective Analysis of RSV Infection in Pediatric Patients: Epidemiology, Comorbidities, Treatment, and Costs in Dubai (2014-2023)

Background: Infections attributable to respiratory syncytial virus (RSV) are a major cause of hospitalization among young children worldwide. Despite substantial clinical and economic burden, real-world data associated with RSV infections in the United Arab Emirates (UAE) are limited. Objectives: This study aimed to assess among children (<18 years) diagnosed with RSV the epidemiology, seasonality, comorbidities, treatment patterns, length of hospital stay, healthcare resource utilization (HCRU), and costs associated with pediatric infection in Dubai, UAE. Methods: This 10-year retrospective cohort study (Jan. 1, 2014-Sept. 30, 2023) utilized Dubai Real-World Database, a private insurance claims database. Patients aged <18 years with a first-episode diagnosis claim (primary or secondary, or a hospital admission) for RSV any time during the index period (Jan. 1, 2014-June 30, 2023) were included. Outcomes were analyzed during a 3-month follow-up. Patients were stratified into 3 cohorts: Cohort 1 (<2 years), Cohort 2 (2 to <6 years), and Cohort 3 (6 to <18 years). Results: Of 28 011 patients identified, 25 729 were aged <18 years with RSV infection. An increasing trend in reported cases was observed from 2014 to 2022, with an average annual increase of 55%. Half of study patients (49.3%) belonged to Cohort 1, with a mean age of 0.6 years, while less than 2% had known risk factors and 22% of the patients in cohort 1 were hospitalized. In Cohort 1, 32.0% had upper respiratory tract infections, 39.4% had lower respiratory tract infections, and 44.4% of patients had an "other respiratory disease." The average length of hospitalization was about 4 days across all cohorts. The total hospitalization cost was highest in patients <2 years, amounting to US 9   798   174 ( m e d i a n , U S 2241.30). Conclusion: Among the RSV patients, 49.3% were <2 years of age and few had recognized risk factors. Among patients <2 years, 22% were hospitalized, with an average hospital stay of 4 days; the cost of hospitalization totaled US $9 798 174. These findings can inform healthcare stakeholders about future policy measures and the need for effective preventive strategies.

An Overview on Disease Burden and Management of Respiratory Syncytial Virus Infections in Older Adults in the Asia-Pacific Region

Respiratory syncytial virus (RSV) represents a significant burden on older adults (aged ≥ 50 years) globally and can lead to acute respiratory tract infections with substantial morbidity and mortality. However, there is a significant gap in knowledge regarding RSV infection in older adults, particularly in the Asia-Pacific region. This knowledge gap underscores the need for targeted and comprehensive studies to fully understand the nuanced epidemiology of RSV in ageing populations. This review synthesises data from various countries, emphasising the impact of RSV on older populations in the Asia-Pacific region. The overall proportions of RSV-related ARIs among older patients ranged from 0.2% to 5.6%. Among older adult patients with CAP, RSV accounted for 1.1%-10.3% of cases. However, it is crucial to note that the diversity in reported percentages highlights the influence of factors such as geographic location, health care settings and diagnostic practices. The most common symptoms observed in older adults with RSV infection were cough, sputum production and fever, followed by dyspnoea, sore throat and rhinorrhoea. Most of the old adults with RSV infection had underlying diseases, and RSV can cause significant morbidity and mortality in old adults. Treatment of RSV infections predominantly involve supportive care, with aerosolised ribavirin reserved for severe cases, especially immunocompromised patients. Emerging antiviral agents, including fusion and nucleoprotein inhibitors, offer promising avenues for future therapeutics. The recent approval of the bivalent RSV prefusion F protein-based vaccine for individuals aged 60 and older represents a milestone in preventive strategies. In conclusion, RSV infection remains a significant threat to older adults in the Asia-Pacific region, necessitating ongoing research and surveillance efforts. The recent vaccine approval marks a positive milestone, but further studies are crucial for refining prevention and treatment approaches.

Key Challenges to Understanding the Burden of Respiratory Syncytial Virus in Older Adults in Southeast Asia, the Middle East, and North Africa: An Expert Perspective

INTRODUCTION

Respiratory syncytial virus (RSV) is a common, highly contagious pathogen and a leading cause of serious illness among infants and older adults. While existing scientific evidence has predominantly focused on the epidemiology and disease burden of RSV in infants, data in older adults remain limited in some countries, including those in Southeast Asia (SEA) and the Middle East and North Africa (MENA) region. Here, we outline the key challenges for understanding the burden of RSV in older adults in SEA and the MENA region and we propose opportunities for improving understanding and eventually reducing the impact of RSV.

MAIN FINDINGS AND CONCLUSIONS

A key challenge identified by the expert group, particularly in older adults, is a lack of awareness (among healthcare professionals, policy makers, and the public) of RSV burden and the associated risks for severe outcomes. This is often confounded by the complexities of underdiagnosis, surveillance limitations, and comorbidities. To address these issues, we suggest medical education initiatives for physicians in SEA and the MENA region to better understand the need to protect older adults from RSV, and encourage more widespread routine testing to better understand the burden of RSV. We also recommend surveillance studies in these regions to provide comprehensive and accurate epidemiological data on RSV in older adults. Finally, in the absence of current surveillance data in these regions, we propose extrapolating existing global data and local pediatric data to inform the likely burden of RSV in older adults. A graphical abstract is available with this article.

Epidemiology and genetic diversity of human respiratory syncytial virus in Belgium between 2011 and 2019

BACKGROUND

Human respiratory syncytial virus (HRSV) is worldwide one of the leading causes of acute respiratory tract infections in young children and the elderly population. Two distinct subtypes of HRSV (A and B) and a multitude of genotypes have been described. The laboratory of Clinical and Epidemiological Virology (KU Leuven/University Hospitals Leuven) has a long-standing history of HRSV surveillance in Belgium.

METHODS

In this study, the seasonal circulation of HRSV in Belgium was monitored during 8 consecutive seasons prior to the SARS-CoV-2 pandemic (2011-2012 until 2018-2019). By use of a multiplex quantitative real time PCR panel, 27,386 respiratory samples were tested for HRSV. Further subtyping and sequencing of the HRSV positive samples was performed by PCR and Sanger sequencing. The prevalence and positivity rate were estimated in 4 distinct age groups and the circulating strains of each subtype were situated in a global context and in reference to the described genotypes in literature.

RESULTS

HRSV circulated in Belgium in a yearly re-occurring pattern during the winter months and both HRSV subtypes co-circulated simultaneously. All HRSV-B strains contained the 60 nt duplication in the HVR2 region of the G gene. Strains of subtype HRSV-A with a 72 nt duplication in the HVR2 region were first observed during the 2011-2012 season and replaced all other circulating strains from 2014 to 2015 onwards.

The impact of the COVID-19 pandemic on respiratory failure caused by respiratory viruses in children and adolescents

Background

In addition to the direct impact of the coronavirus disease 2019 (COVID-19) pandemic on child/adolescent health, changes in infections caused by other viruses have been observed. Respiratory syncytial virus (RSV) and influenza are important agents of acute respiratory failure (ARF) in these age groups. This study presents an analysis of the influence of the pandemic on the seasonal and clinical patterns of ARF caused by RSV and influenza.

Methods

A retrospective ecological study was performed. The data of individuals younger than 20 years who were hospitalized with ARF and who were diagnosed with RSV, influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between 2019 and 2022 were analysed. The data were collected from the governmental system.

Results

Among 367,136 individuals, the incidence of ARF increased annually. During the pandemic, the number of infected schoolchildren, adolescents, and nonwhite people; intensive care admissions; and mortality rates increased. Older age, SARS-CoV-2 infection, and residence in North Brazil/Northeast Brazil were associated with lower odds of intensive care unit admission but greater odds of death. Comorbidities were important risk factors for severe disease. There was a drastic reduction in the number of RSV and influenza infections, with a resurgence in 2021. After the resurgence in 2021, the number of influenza-related deaths remained above the 2019 level, which did not occur in 2022. After 2021, RSV infection was associated with greater odds of intensive care admission but not death.

Conclusions

During the pandemic, older children, adolescents, and individuals with comorbidities were more vulnerable to ARF. There was a reduction in the prevalence and severity of RSV and influenza infections. After this reduction, a resurgence with an out-of-season pattern, but without higher odds of death than in the prepandemic year, was observed for both in 2022.

Recent Progress toward the Discovery of Small Molecules as Novel Anti-Respiratory Syncytial Virus Agents

Respiratory syncytial virus (RSV) stands as the foremost cause of infant hospitalization globally, ranking second only to malaria in terms of infant mortality. Although three vaccines have recently been approved for the prophylaxis of adults aged 60 and above, and pregnant women, there is currently no effective antiviral drug for treating RSV infections. The only preventive measure for infants at high risk of severe RSV disease is passive immunization through monoclonal antibodies. This Perspective offers an overview of the latest advancements in RSV drug discovery of small molecule antivirals, with particular focus on the promising findings from agents targeting the fusion and polymerase proteins. A comprehensive reflection on the current state of RSV research is also given, drawing inspiration from the lessons gleaned from HCV and HIV, while also considering the impact of the recent approval of the three vaccines.

Occurrence of Central Nervous System Complications of Respiratory Syncytial Virus Infections: A Systematic Review with Meta-Analysis

An increasing base of evidence suggests that respiratory syncytial virus (RSV) infections may be associated with neurological complications. In accord with the PRISMA statement, we performed a systematic review and meta-analysis on the occurrence of encephalitis and encephalopathy associated with documented RSV infections. PubMed, Embase, and Scopus databases were searched for eligible observational studies published up to 10 April 2024. Raw data included the occurrence of RSV infections among cases of encephalitis and/or encephalopathy and cases of encephalitis and/or encephalopathy among series of RSV infections. Data were pooled in a random effects model. Case reports were also collected, and their data pooled as a cumulative series. Heterogeneity was assessed using the I2 measure, while reporting bias was assessed by means of funnel plots and regression analysis. A total of 15 studies for a total of 7719 RSV infections and 1631 cases of encephalitis were analyzed. Moreover, 27 case reports and case series were retrieved, for a total of 84 individual cases of encephalitis/encephalopathy occurring during a documented RSV infection. A pooled prevalence of 2.20 cases of encephalitis/encephalopathy per 100 RSV cases (I2 = 99%) was calculated, while a prevalence of RSV infections among cases of encephalitis/encephalopathy was estimated to 3.53 per 100 cases for studies on respiratory specimens (I2 = 48%) and 0.37 per cases on central nervous system (CNS) specimens (I2 = 0%). Detection of RSV within the CNS was relatively rare (17.86% of pooled case reports), being associated with male gender (adjusted odds ratio [aOR] 5.021, 95% confidence interval [95%CI] 1.104 to 22.831) and recovery with long-term sequelae (aOR 5.699, 95%CI 1.152; 28.183). Case fatality ratio was estimated to be 0.43 per 100 cases on observational studies and 10.71% in case reports, a difference likely due to publication bias. In summary, RSV represented a not frequent but notable cause of encephalitis/encephalopathy in adults and children. The paucity of available studies not only recommends a cautious appraisal of our results but stresses the clinical significance of future studies on incident cases of encephalitis and/or encephalopathy.

Impact of Nirsevimab Immunization on Pediatric Hospitalization Rates: A Systematic Review and Meta-Analysis (2024)

A systematic review with a meta-analysis was performed to gather available evidence on the effectiveness of monoclonal antibody nirsevimab in the prevention of lower respiratory tract diseases (LRTDs) due to respiratory syncytial virus (RSV) in children and newborns (CRD42024540669). Studies reporting on real-world experience and randomized controlled trials (RCTs) were searched for in three databases (PubMed, Embase, and Scopus) until 1 May 2024. Our analysis included five RCTs, seven real-world reports, and one official report from the health authorities. Due to the cross-reporting of RCTs and the inclusion of multiple series in a single study, the meta-analysis was performed on 45,238 infants from 19 series. The meta-analysis documented a pooled immunization efficacy of 88.40% (95% confidence interval (95% CI) from 84.70 to 91.21) on the occurrence of hospital admission due to RSV, with moderate heterogeneity (I2 24.3%, 95% CI 0.0 to 56.6). Immunization efficacy decreased with the overall length of the observation time (Spearman's r = -0.546, p = 0.016), and the risk of breakthrough infections was substantially greater in studies with observation times ≥150 days compared to studies lasting <150 days (risk ratio 2.170, 95% CI 1.860 to 2.532). However, the effect of observation time in meta-regression analysis was conflicting (β = 0.001, 95% CI -0.001 to 0.002; p = 0.092). In conclusion, the delivery of nirsevimab was quite effective in preventing hospital admissions due to LRTDs. However, further analyses of the whole RSV season are required before tailoring specific public health interventions.

Respiratory Syncytial Virus Infections in Recipients of Bone Marrow Transplants: A Systematic Review and Meta-Analysis

Human Respiratory Syncytial Virus (RSV) is a common cause of respiratory tract infections. Usually associated with infants and children, an increasing amount of evidence suggests that RSV can cause substantial morbidity and mortality in immunocompromised individuals, including recipients of bone marrow transplantation (BMT). The present systematic review was therefore designed in accordance with the PRISMA guidelines to collect available evidence about RSV infections in BMT recipients. Three medical databases (PubMed, Embase, and MedRxiv) were therefore searched for eligible observational studies published up to 30 September 2023 and collected cases were pooled in a random-effects model. Heterogeneity was assessed using I2 statistics. Reporting bias was assessed by means of funnel plots and regression analysis. Overall, 30 studies were retrieved, including 20,067 BMT cases and 821 RSV infection episodes. Of them, 351 were lower respiratory tract infections, and a total of 78 RSV-related deaths were collected. A pooled attack rate of 5.40% (95% confidence interval [95%CI] 3.81 to 7.60) was identified, with a corresponding incidence rate of 14.77 cases per 1000 person-years (95%CI 9.43 to 20.11), and a case fatality ratio (CFR) of 7.28% (95%CI 4.94 to 10.60). Attack rates were higher in adults (8.49%, 95%CI 5.16 to 13.67) than in children (4.79%, 95%CI 3.05 to 7.45), with similar CFR (5.99%, 95%CI 2.31 to 14.63 vs. 5.85%, 95%CI 3.35 to 10.02). By assuming RSV attack rates as a reference group, influenza (RR 0.518; 95%CI 0.446 to 0.601), adenovirus (RR 0.679, 95%CI 0.553 to 0.830), and human metapneumovirus (RR 0.536, 95%CI 0.438 to 0.655) were associated with a substantially reduced risk for developing corresponding respiratory infection. Despite the heterogeneous settings and the uneven proportion of adult and pediatric cases, our study has identified high attack rates and a substantial CFR of RSV in recipients of BMT, stressing the importance of specifically tailored preventive strategies and the need for effective treatment options.

Impact and cost-effectiveness analyses of vaccination for prevention of respiratory syncytial virus disease among older adults in Ontario: A Canadian Immunization Research Network (CIRN) study

BACKGROUND

Two prefusion F protein-based vaccines, Arexvy and Abrysvo, have been approved by Health Canada for protecting older adults against respiratory syncytial virus (RSV)-associated lower respiratory tract disease. We estimated the health benefits and cost-effectiveness of these vaccines under a publicly funded single-dose vaccination program in Ontario that targets residents of long-term care homes (LTCHs). Additionally, we evaluated an extended program that broadens vaccination to include community-dwelling older adults.

METHODS

A discrete-event simulation model was parameterised with the burden of RSV disease including outpatient care, hospitalisation, and death among adults aged 60 years or older in Ontario, Canada. Accounting for direct and indirect costs (in 2023 Canadian dollars) associated with RSV-related outcomes, we calculated the net monetary benefit using quality-adjusted life-year (QALY) gained, and determined the range of price-per-dose (PPD) for vaccination programs to be cost-effective from both healthcare and societal perspectives over two RSV seasons. The incremental cost-effectiveness ratio (ICER) was calculated to estimate the additional costs required to gain one QALY.

RESULTS

Using a willingness-to-pay of $50,000 per QALY gained, we found that vaccinating 90% of residents in LTCHs with Arexvy would be cost-effective from a societal perspective for a PPD up to $163, producing a mean ICER value of $49,984 (95% CI: $47,539 to $52,704) per QALY gained with a two-year budget impact of $463,468 per 100,000 older adults. The reduction of hospitalizations was estimated at 7.0% compared to the no-vaccination scenario. Extending the program to include community-dwelling older adults with a 74% coverage akin to influenza vaccination, Arexvy remains cost-effective for a PPD up to $139, with a mean ICER value of $49,698 (95% CI: 48,022 to 51,388) per QALY gained and a two-year budget impact of $8.63 million. Compared to the no-vaccination scenario, the extended program resulted in a 57.3% reduction in RSV-related hospitalisations.

CONCLUSIONS

Vaccinating residents of LTCHs against RSV disease would be cost-effective depending on PPD; extending the program to community-dwelling older adults would provide substantial health benefits, averting significant direct healthcare costs and productivity losses.

Epidemiology and burden of respiratory syncytial virus in Italian adults: A systematic review and meta-analysis

OBJECTIVE

Respiratory syncytial virus (RSV) is a common respiratory pathogen not only in children, but also in adults. In view of a recent authorization of adult RSV vaccines in Italy, our research question was to quantify the epidemiology and burden of RSV in Italian adults.

METHODS

Observational studies on the epidemiology and clinical burden of laboratory-confirmed or record-coded RSV infection in Italian adults of any age were eligible. Studies with no separate data for Italian adults, modeling and other secondary publications were excluded. A literature search was performed in MEDLINE, Biological Abstracts, Global Health, Scopus and Web of Science on 22 November 2023. Critical appraisal was performed by means of a Joanna Briggs Institute checklist. Random-effects (RE) meta-analysis was performed to obtain pooled estimates and the observed heterogeneity was investigated by subgroup and meta-regression analyses. The protocol was prospectively registered (doi.org/10.17504/protocols.io.5qpvo32odv4o/v1).

RESULTS

Thirty-five studies were identified, most of which had at least one possible quality concern. RSV seasonal attack rates ranged from 0.8 ‰ in community-dwelling older adults to 10.9% in hematological outpatients. In the RE model, 4.5% (95% CI: 3.2-5.9%) of respiratory samples tested positive for RSV. This positivity prevalence was higher in older adults (4.4%) than in working-age adults (3.5%) and in outpatient (4.9%) than inpatient (2.9%) settings. According to the meta-regression, study location and sample size were also significant predictors of RSV detection frequency. The pooled estimate of in-hospital mortality was as high as 7.2% (95% CI: 4.7-10.3%). Data on other indicators of the diseases burden, such as complication and hospitalization rates, were unavailable.

CONCLUSION

RSV poses a measurable burden on Italian adults, especially those of older age and with some co-morbidities. However, several data on the natural history of RSV disease are missing and should be established by future large-scale studies.

Understanding the Burden of Respiratory Syncytial Virus in Older Adults in Latin America: An Expert Perspective on Knowledge Gaps

Respiratory syncytial virus (RSV) is a significant global health concern and major cause of hospitalization, particularly among infants and older adults. The clinical impact of RSV is well characterized in infants; however, in many countries, the burden and risk of RSV in older populations are overlooked. In Latin America, there are limited data on RSV epidemiology and disease management in older adults. Therefore, the impact of RSV in this region needs to be addressed. Here, current insights on RSV infections in older populations in Latin America, including those with underlying health conditions, are discussed. We also outline the key challenges limiting our understanding of the burden of RSV in Latin America in a worldwide context and propose an expert consensus to improve our understanding of the burden of RSV in the region. By so doing, we aim to ultimately improve disease management and outcomes of those at risk and to alleviate the impact on healthcare systems.A graphical plain language summary is available with this article.

Epidemiology and Disease Burden of Respiratory Syncytial Virus Infection in Adults

Respiratory syncytial virus (RSV) constitutes a significant cause of respiratory illness and mortality among older adults, a demographic that is expanding with considerable impact on healthcare systems worldwide. The actual burden of RSV in this population may still be underestimated, owing to factors such as low awareness and suboptimal diagnostic sensitivity in adults, the lack of robust RSV surveillance systems, and the infrequent use of diagnostic testing. Recent advancements in respiratory virus detection have spurred further exploration into appropriate preventive and therapeutic strategies. The recent approval of two vaccines highlights the critical need for the precise estimation of the RSV disease burden to optimize the effectiveness and cost-efficiency of immunization programs. This narrative review aimed to summarize the existing knowledge of the RSV burden in adults with a particular focus on older adults, incorporating data from Korea. Overall, current estimates indicate that the annual RSV attack rate in the general adult population ranges from 1 - 7%, increasing to approximately 4 - 10% among elderly and high-risk groups. The in-hospital mortality rate can be estimated to be around 7 - 10%, rising up to 40% among intensive care unit-admitted patients. To elucidate RSV's disease burden, further continuing research, including population-based studies, is necessary.

Respiratory Syncytial Virus Vaccination Recommendations for Adults Aged 60 Years and Older: The NeumoExperts Prevention Group Position Paper

Respiratory syncytial virus (RSV) is a major cause of respiratory tract infections in adults, particularly older adults and those with underlying medical conditions. Vaccination has emerged as a potential key strategy to prevent RSV-related morbidity and mortality. This Neumoexperts Prevention (NEP) Group scientific paper aims to provide an evidence-based positioning and RSV vaccination recommendations for adult patients. We review the current literature on RSV burden and vaccine development and availability, emphasising the importance of vaccination in the adult population. According to our interpretation of the data, RSV vaccines should be part of the adult immunisation programme, and an age-based strategy should be preferred over targeting high-risk groups. The effectiveness and efficiency of this practice will depend on the duration of protection and the need for annual or more spaced doses. Our recommendations should help healthcare professionals formulate guidelines and implement effective vaccination programmes for adult patients at risk of RSV infection now that specific vaccines are available.

Predictors of prolonged length of hospital stay and in-hospital mortality in patients aged 1-24 months with acute bronchiolitis in Douala, Cameroon

INTRODUCTION

In Cameroon, acute bronchiolitis has been reported as the third commonest lower respiratory infection and is usually associated with low mortality. Nonetheless, respiratory distress associated with non-adherence to management guidelines can prolong hospital stay. This study aimed to explore predictors of prolonged hospital stay (≥ 5 days) and mortality in patients aged < 2years hospitalised for acute bronchiolitis.

METHODOLOGY

We conducted a retrospective cohort study at three paediatric units in the city of Douala, Cameroon. Factors associated with prolonged hospital stay and mortality were determined using multivariable linear regression model. Threshold for significance was set at p ≤ 0.05.

RESULTS

A total of 215 patients with bronchiolitis were included with mean age of 6.94 ± 5.71 months and M/F sex ratio of 1.39/1. Prolonged hospital stay was reported in 46.98% and mortality in 10.70% of patients hospitalised for bronchiolitis. Factors independently associated with prolonged hospital duration were oxygen administration [b = 0.36, OR = 2.35 (95% CI:1.16-4.74), p = 0.017], abnormal respiratory rate [b = 0.38, OR = 2.13 (1.00-4.55), p = 0.050] and patients presenting with cough [b = 0.33, OR = 2.35 (95% CI: 1.22-4.51), p = 0.011], and diarrhoea [b = 0.71, OR = 6.44 (95% CI: 1.6-25.86), p = 0.009] on admission. On the other hand, factors independently associated with mortality were age of the patient [b= -0.07, OR = 0.84 (95% CI: 0.74-0.97), p = 0.014] and oxygen administration [b = 1.08, OR = 9.64 (95% CI:1.16-79.85), p = 0.036] CONCLUSION: Acute bronchiolitis represented 1.24% of admissions and was common in the rainy season, in males and 3-11-month-old patients. Management guidelines were poorly respected. Prolonged length of stay was reported in half of the patients hospitalized and mortality was high, especially in younger patients and in patients receiving oxygen.

Respiratory Syncytial Virus, Influenza and SARS-CoV-2 in Homeless People from Urban Shelters: A Systematic Review and Meta-Analysis (2023)

Homeless people (HP) are disproportionally affected by respiratory disorders, including pneumococcal and mycobacterial infections. On the contrary, more limited evidence has been previously gathered on influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and very little is known about the occurrence of human respiratory syncytial virus (RSV), a common cause of respiratory tract infections among children and the elderly. The present systematic review was designed to collect available evidence about RSV, influenza and SARS-CoV-2 infections in HP, focusing on those from urban homeless shelters. Three medical databases (PubMed, Embase and Scopus) and the preprint repository medRxiv.org were therefore searched for eligible observational studies published up to 30 December 2023, and the collected cases were pooled in a random-effects model. Heterogeneity was assessed using the I2 statistics. Reporting bias was assessed by funnel plots and a regression analysis. Overall, 31 studies were retrieved, and of them, 17 reported on the point prevalence of respiratory pathogens, with pooled estimates of 4.91 cases per 1000 HP (95%CI: 2.46 to 9.80) for RSV, 3.47 per 1000 HP for influenza and 40.21 cases per 1000 HP (95%CI: 14.66 to 105.55) for SARS-CoV-2. Incidence estimates were calculated from 12 studies, and SARS-CoV-2 was characterized by the highest occurrence (9.58 diagnoses per 1000 persons-months, 95%CI: 3.00 to 16.16), followed by influenza (6.07, 95%CI: 0.00 to 15.06) and RSV (1.71, 95%CI: 0.00 to 4.13). Only four studies reported on the outcome of viral infections in HP: the assessed pathogens were associated with a high likelihood of hospitalization, while high rates of recurrence and eventual deaths were reported in cases of RSV infections. In summary, RSV, influenza and SARS-CoV-2 infections were documented in HP from urban shelters, and their potential outcomes stress the importance of specifically tailored preventive strategies.

The domestication of SARS-CoV-2 into a seasonal infection by viral variants

Introduction

The COVID-19 pandemic was caused by the zoonotic betacoronavirus SARS-CoV-2. SARS-CoV-2 variants have emerged due to adaptation in humans, shifting SARS-CoV-2 towards an endemic seasonal virus. We have termed this process 'virus domestication'.

Methods

We analyzed aggregate COVID-19 data from a publicly funded healthcare system in Canada from March 7, 2020 to November 21, 2022. We graphed surrogate calculations of COVID-19 disease severity and SARS-CoV-2 variant plaque sizes in tissue culture.

Results and Discussion

Mutations in SARS-CoV-2 adapt the virus to better infect humans and evade the host immune response, resulting in the emergence of variants with altered pathogenicity. We observed a decrease in COVID-19 disease severity surrogates after the arrival of the Delta variant, coinciding with significantly smaller plaque sizes. Overall, we suggest that SARS-CoV-2 has become more infectious and less virulent through viral domestication. Our findings highlight the importance of SARS-CoV-2 vaccination and help inform public policy on the highest probability outcomes during viral pandemics.