Respiratory Syncytial Virus Hospitalization Research Articles

Respiratory syncytial virus epidemiology and clinical severity before and during the COVID-19 pandemic in British Columbia, Canada: a retrospective observational study

The COVID-19 pandemic has perturbed the seasonality of respiratory syncytial virus (RSV) infections. However, we lack data on how this impacted the severity of paediatric RSV cases. The objective of this study was to describe the clinical severity of RSV cases before, during and after pandemic measures in British Columbia (BC), Canada. Retrospective study of RSV cases from September 1st, 2017 to May 15th, 2023, with a review of RSV outcomes in children below 18 years old at BC's paediatric hospital. Temporal changes in RSV cases and hospitalisations were quantified using interrupted time series. BC experienced only 11 RSV cases (from 95,266 tests) between September 2020 and August 2021. This was followed by a resurgence of 9,529 RSV cases (219,566 tests [4.3% positive tests]) in 2021-22 and 8,215 cases (124,449 tests [6.6% positive tests]) in 2022-23, increased compared to 1,750 cases (48,664 tests [3.6% positive tests]) per corresponding yearly period in 2017-20. From September 2017 to May 2023, the median age of children with RSV at BC Children's Hospital increased from 8.7 [IQR: 2.0-26.0] to 19.6 [3.9-43.7] months per yearly period. More children were hospitalised in 2022-23 (n=360), compared to 2017-20 (n=168 per period) and 2021-22 (n=172). However, we detected no increase in hospitalisations or ICU admissions in children born prematurely or with chronic cardiorespiratory conditions. The increased detection of symptomatic RSV cases in older children in 2021-22 and increased RSV-related hospitalisations in 2022-23 suggest a gradual increase in the pool of immunologically vulnerable children due to a prolonged lack of viral exposure. Government of Canada via its COVID-19 Immunity Task Force.

Epidemiology of Medically Attended Respiratory Syncytial Virus Lower Respiratory Tract Infection in Japanese Children, 2011-2017.

The objective was to report critical respiratory syncytial virus (RSV)-related epidemiological and healthcare resource utilization measures among Japanese children stratified by gestational and chronological age groups. The JMDC (formerly the Japan Medical Data Center) was used to retrospectively identify infants with or without RSV infection (beginning between 1 February 2011 and 31 January 2016, with follow-up through 31 December 2017). The incidence of RSV medically attended lower respiratory tract infection (MALRI) was captured by flagging hospitalizations, outpatient, and emergency department/urgent care visits with an RSV diagnosis code during the season. Of 113 529 infants and children identified, 17 022 (15%) had an RSV MALRI (14 590 during the season). The RSV MALRI and hospitalization rates in the first 5 months were 14.3/100 child-years (CY) and 6.0/100 CY, respectively (13.4/100 and 5.8/100 CY for full-term infants and 20/100 and 6.8/100 CY for late preterm infants, respectively). Among those with ≥1 type of MALRI event during the RSV season, >80% of children had it by 24 months of chronological age, although this observation differed by prematurity status. Sixty percent of healthcare resource utilization measures started in the outpatient setting. This study emphasizes the RSV burden in young children and critically highlights the data needed to make decisions about new preventive strategies.

A new cost-utility analysis assessing risk factor-guided prophylaxis with palivizumab for the prevention of severe respiratory syncytial virus infection in Italian infants born at 29-35 weeks' gestational age.

Since the last Italian cost-utility assessment of palivizumab in 2009, new data on the burden of respiratory syncytial virus (RSV) and an International Risk Scoring Tool (IRST) have become available. The objective of this study was to provide an up-to-date cost-utility assessment of palivizumab versus no prophylaxis for the prevention of severe RSV infection in otherwise healthy Italian infants born at 29-31 weeks' gestational age (wGA) infants and those 32-35wGA infants categorized as either moderate- or high-risk of RSV-hospitalization (RSVH) by the IRST. A decision tree was constructed in which infants received palivizumab or no prophylaxis and then could experience: i) RSVH; ii) emergency room medically-attended RSV-infection (MARI); or, iii) remain uninfected/non-medically attended. RSVH cases that required intensive care unit admission could die (0.43%). Respiratory morbidity was considered in all surviving infants up to 18 years of age. Hospitalization rates were derived from Italian data combined with efficacy from the IMpact-RSV trial. Palivizumab costs were calculated from vial prices (50mg: €490.37 100mg: €814.34) and Italian birth statistics combined with a growth algorithm. A lifetime horizon and healthcare and societal costs were included. The incremental cost-utility ratio (ICUR) was €14814 per quality-adjusted life year (QALY) gained in the whole population (mean: €15430; probability of ICUR being <€40000: 0.90). The equivalent ICURs were €15139 per QALY gained (€15915; 0.89) for 29-31wGA infants and €14719 per QALY gained (€15230; 0.89) for 32-35wGA infants. The model was most sensitive to rates of long-term sequelae, utility scores, palivizumab cost, and palivizumab efficacy. Palivizumab remained cost-effective in all scenario analyses, including a scenario wherein RSVH infants received palivizumab without a reduction in long-term sequelae and experienced a 6-year duration of respiratory morbidity (ICUR: €27948 per QALY gained). In conclusion, palivizumab remains cost-effective versus no prophylaxis in otherwise healthy Italian preterm infants born 29-35wGA. The IRST can help guide cost-effective use of palivizumab in 32-35wGA infants.

Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children.

RSV often leads to hospitalization, and accurate knowledge of risk factors is crucial. We retrospectively analyzed laboratory-confirmed RSV hospitalizations regarding pregnancy factors, birth status, cigarette smoke exposure, nutrition, social conditions, clinical presentation, and severe disease defined as a need for passive oxygen therapy (pO2Tx), the presence of pneumonia, respiratory failure, intensive care unit (ICU) transfer, and prolonged hospitalization. A univariate analysis included 594 children (median age 4 months) and revealed a pO2Tx relationship with age ≤ 3 months (OR = 1.56), prematurity (OR = 1.71), being born during RSV season (OR = 1.72), smoke exposure during pregnancy (both parents (OR = 2.41, father (OR = 1.8)), dyspnea (OR = 5.09), and presence of apnea (OR = 5.81). Pneumonia was associated with maternal smoke exposure (OR = 5.01), fever (OR = 3.92), dyspnea (OR = 1.62), history of aspiration (OR = 4.63), and inversely with age ≤ 3 months (OR = 0.45). Respiratory failure was associated with prematurity (OR = 3.13) and apnea (OR = 18.78), while the lower odds were associated with older age (OR = 0.57 per month) and presence of fever (OR = 0.11). ICU transfer was associated with apnea (OR = 17.18), but an inverse association was observed with age (OR = 0.54) and fever (OR = 0.11). A prolonged hospital stay was associated with prematurity (OR = 1.76), low birth weight (OR = 2.89), aspiration (OR = 4.93), and presence of fever (OR = 1.51). Age (up to 3 months), prematurity, and presence of apnea are risk factors for a severe RSV course.

Cost and health-related quality of life for children hospitalized with respiratory syncytial virus in Central China.

The economic burden of respiratory syncytial virus (RSV) infection and its impact on health-related quality of life (HRQoL) are not well-understood in China. This study assessed total cost and HRQoL for children hospitalized with RSV in Central China. Based on a prospective case series study in Henan Province in 2020-2021, inpatients aged 0-59 months with RSV-related acute respiratory infections (ARIs) were included into analysis. Total cost included direct medical cost (sum of medical cost before and during hospitalization), direct non-medical cost, and indirect cost. Direct medical cost during hospitalization data were extracted from the hospital information system. Other costs and HRQoL status were obtained from a telephone survey conducted in the caregivers of the enrolled patients. Among 261 RSV-infected inpatients, caregivers of 170 non-severe cases (65.1%, 170/261) were successfully interviewed. Direct medical cost per episode was 1055.3 US dollars (US$) (95% CI: 998.2-1112.5 US$). Direct non-medical cost and indirect cost per episode were 83.6 US$ (95% CI: 77.5-89.7 US$) and 162.4 US$ (95% CI: 127.9-197.0 US$), respectively. Quality adjusted life years (QALY) loss for non-severe RSV hospitalization was 8.9 × 10-3 (95% CI: 7.9 × 10-3 -9.9 × 10-3 ). The majority of inpatients were <1 year of age comprising significantly higher cost and more QALY loss than older children. RSV-associated hospitalization poses high economic and health burden in Central China particularly for children <1 year old. Our findings are crucial for determining the priority of interventions and allocation of health resources.

Safety, efficacy and pharmacokinetics of palivizumab in off-label neonates, infants, and young children at risk for serious respiratory syncytial virus infection: a multicenter phase II clinical trial

Pediatric patients with certain rare diseases are at increased risk of severe respiratory syncytial virus (RSV) infection. However, the prophylactic use of anti-RSV antibody (palivizumab) in these patients is not indicated at present in Japan. This first-in-the-world multicenter, uncontrolled, open-label, phase II clinical trial was carried out between 28 July 2019 and 24 September 2021at seven medical institutions in Japan to investigate the efficacy, safety, and pharmacokinetics of palivizumab in 23 subjects recruited from among neonates, infants, or children aged 24 months or younger who had any of the following conditions: pulmonary hypoplasia, airway stenosis, congenital esophageal atresia, inherited metabolic disease, or neuromuscular disease. At least four continuous doses of palivizumab were administered intramuscularly at 15mg/kg at intervals of 30 days. Twenty-three enrolled subjects completed the study. No subject required hospitalization for RSV. Adverse events (AE) did not notably differ from the event terms described in the latest interview form. Five severe AEs required unplanned hospitalization, but resolved without RSV infection. Therapeutically effective concentrations of palivizumab were maintained throughout the study period. Palivizumab might be well tolerated and effective in preventing serious respiratory symptoms and hospitalization due to severe RSV infection, indicating the prophylactic use in the pediatric patients included in this study. Japan Agency for Medical Research and Development (AMED), grant numbers 19lk0201097h0001 (to MM), 20lk0201097h0002 (to MM), 21lk0201097h0003 (to MM), and 22lk0201097h0004 (to MM). AMED did not have any role in the execution of this study, analysis and interpretation of the data, or the decision to submit the results.

Year-Round Respiratory Syncytial Virus Transmission in The Netherlands Following the COVID-19 Pandemic: A Prospective Nationwide Observational and Modeling Study.

We initiated a nationwide prospective study to monitor respiratory syncytial virus (RSV)-related pediatric hospitalizations in 46 hospitals throughout the Netherlands between May 2021 and August 2022. We showed year-round RSV transmission in the Netherlands after an initial 2021 summer outbreak. The pattern was unprecedented and distinct from neighboring countries. We extended a dynamic simulation model to evaluate the impact of waning immunity on pediatric RSV hospitalizations in the Netherlands using 4 different scenarios. Our results suggest that the observed continuous RSV transmission pattern could be associated with waning immunity due to the period of very low RSV circulation during the COVID-19 pandemic.

The age profile of respiratory syncytial virus burden in preschool children of low- and middle-income countries: A semi-parametric, meta-regression approach.

Respiratory syncytial virus (RSV) infections are among the primary causes of death for children under 5 years of age worldwide. A notable challenge with many of the upcoming prophylactic interventions against RSV is their short duration of protection, making the age profile of key interest to the design of prevention strategies. We leverage the RSV data collected on cases, hospitalizations, and deaths in a systematic review in combination with flexible generalized additive mixed models (GAMMs) to characterize the age burden of RSV incidence, hospitalization, and hospital-based case fatality rate (hCFR). Due to the flexible nature of GAMMs, we estimate the peak, median, and mean incidence of infection to inform discussions on the ideal "window of protection" of prophylactic interventions. In a secondary analysis, we reestimate the burden of RSV in all low- and middle-income countries. The peak age of community-based incidence is 4.8 months, and the mean and median age of infection is 18.9 and 14.7 months, respectively. Estimating the age profile using the incidence coming from hospital-based studies yields a slightly younger age profile, in which the peak age of infection is 2.6 months and the mean and median age of infection are 15.8 and 11.6 months, respectively. More severe outcomes, such as hospitalization and in-hospital death have a younger age profile. Children under 6 months of age constitute 10% of the population under 5 years of age but bear 20% to 29% of cases, 28% to 39% of hospitalizations, and 38% to 50% of deaths. On an average year, we estimate 28.23 to 31.34 million cases of RSV, between 2.95 to 3.35 million hospitalizations, and 16,835 to 19,909 in-hospital deaths in low, lower- and upper middle-income countries. In addition, we estimate 17,254 to 23,875 deaths in the community, for a total of 34,114 to 46,485 deaths. Globally, evidence shows that community-based incidence may differ by World Bank Income Group, but not hospital-based incidence, probability of hospitalization, or the probability of in-hospital death (p ≤ 0.01, p = 1, p = 0.86, 0.63, respectively). Our study is limited mainly due to the sparsity of the data, especially for low-income countries (LICs). The lack of information for some populations makes detecting heterogeneity between income groups difficult, and differences in access to care may impact the reported burden. We have demonstrated an approach to synthesize information on RSV outcomes in a statistically principled manner, and we estimate that the age profile of RSV burden depends on whether information on incidence is collected in hospitals or in the community. Our results suggest that the ideal prophylactic strategy may require multiple products to avert the risk among preschool children.

Respiratory syncytial virus-associated hospitalization in children aged

ABSTRACT Respiratory syncytial virus (RSV) is the leading cause of severe respiratory infections in children. In many countries, changes in RSV hospitalizations have occurred during COVID-19 restriction, with alterations in annual pre-pandemic trends. The objective of this retrospective study was to describe the epidemiology of RSV during the pandemic in Spain (2018–2021) through population-based estimates of hospitalization in children <2 years old. A total of 56,741 hospital discharges were identified with a 2.2% decrease between the beginning and the end of the COVID-19 pandemic resulting in a hospitalization rate of 1,915.89 (95% CI = 1,900.13–1,931.65) hospitalizations per 100,000 children. During the four-year period, a total of 34 deaths were recorded (males 63%, females 37%). The average annual cost to the National Health-Care System of bronchiolitis requiring hospitalization was €49,6 million with an average hospitalization cost per case of €3,054. RSV is a very frequent virus associated with community-acquired pneumonia (CAP) in children under 2 years old, so future preventive interventions should target this age group including vaccination programs.

RSV Burden and Its Impact on Pediatric Inpatient Bed Occupancy in Belgium: An Analysis of National Hospital Claims Data.

Respiratory syncytial virus (RSV) infections represent a substantial burden on pediatric services during winter. While the morbidity and financial burden of RSV are well studied, less is known about the organizational impact on hospital services (ie, impact on bed capacity and overcrowding and variation across hospitals). Retrospective analysis of the population-wide Belgian Hospital Discharge Data Set for the years 2017 and 2018 (including all hospital sites with pediatric inpatient services), covering all RSV-associated (RSV-related International Classification of Diseases, 10th Version, Clinical Modification diagnoses) inpatient hospitalization by children under 5 years old as well as all-cause acute hospitalizations in pediatric wards. RSV hospitalizations amount to 68.3 hospitalizations per 1000 children less than 1 year and 5.0 per 1000 children 1-4 years of age and are responsible for 20%-40% of occupied beds during the peak period (November-December). The mean bed occupancy rate over the entire year (2018) varies across hospitals from 22.8% to 85.1% and from 30.4% to 95.1% during the peak period. Small-scale pediatric services (<25 beds) are more vulnerable to the volatility of occupancy rates. Forty-six hospital sites have daily occupancy rates above 100% (median of 9 days). Only in 1 of 23 geographically defined hospital networks these high occupancy rates are on the same calendar days. Pediatric services tend to be over-dimensioned to deal with peak activity mainly attributable to RSV. RSV immunization can substantially reduce pediatric capacity requirements. Enhanced collaboration in regional networks is an alternative strategy to deal with peaks and reduce capacity needs.

Burden of illness associated with Respiratory Syncytial Virus (RSV)-related hospitalizations among adults in Ontario, Canada: A retrospective population-based study

BackgroundGlobally, RSV is a common viral pathogen that causes 64 million acute respiratory infections annually. Our objective was to determine the incidence of hospitalization, healthcare resource use and associated costs of adults hospitalized with RSV in Ontario, Canada. MethodsTo describe the epidemiology of adults hospitalized with RSV, we used a validated algorithm applied to a population-based healthcare utilization administrative dataset in Ontario, Canada. We created a retrospective cohort of incident hospitalized adults with RSV between September 2010 and August 2017 and followed each person for up to two years. To determine the burden of illness associated with hospitalization and post-discharge healthcare encounters each RSV-admitted patient was matched to two unexposed controls based on demographics and risk factors. Patient demographics were described and mean attributable 6-month and 2-year healthcare costs (2019 Canadian dollars) were estimated. ResultsThere were 7,091 adults with RSV-associated hospitalizations between 2010 and 2019 with a mean age of 74.6 years; 60.4 % were female. RSV-coded hospitalization rates increased from 1.4 to 14.6 per 100,000 adults between 2010–2011 and 2018–2019. The mean difference in healthcare costs between RSV-admitted patients and matched controls was $28,260 (95 % CI: $27,728 - $28,793) in the first 6 months and $43,721 over 2 years (95 % CI: $40,383 – $47,059) post-hospitalization. ConclusionsRSV hospitalizations among adults increased in Ontario between 2010/11 to 2018/19 RSV seasons. RSV hospitalizations in adults were associated with increased attributable short-term and long-term healthcare costs compared to matched controls. Interventions that could prevent RSV in adults may reduce healthcare burden.

Non-specific benefit of seasonal influenza vaccine on respiratory syncytial virus-hospitalisations in children: An instrumental variable approach using population-based data

BackgroundSeasonal influenza vaccine is effective against influenza hospitalisations, but little is known about non-specific effects of the vaccine on other respiratory pathogens with similar seasonal patterns. We aimed to assess the causal impact of seasonal influenza vaccine on laboratory-confirmed hospitalisations for respiratory syncytial virus (RSV) in children using an instrumental variable (IV) strategy. MethodsWe used probabilistically linked population-based data on childhood immunisations, births, deaths, hospitalisations, perinatal factors, and microbiology test results (2000–2013) of all Western Australian (WA) children born 2000–2012, observed longitudinally until the earliest of 7 years of age or 31 December 2013. We exploited a unique natural experiment created from the WA’s state-funded preschool influenza vaccination policy commencing in 2008 and used this as an instrument for children’s seasonal influenza vaccination status. We estimated a system of two simultaneous probit equations: determinants of influenza vaccine uptake, and determinants of RSV-confirmed hospitalisation. ResultsInfluenza vaccine coverage was low prior to 2008 but increased to 36 % in children aged 6–23 months in 2009. The majority (90 %) of RSV-hospitalisations occurred in children <2 years. Receipt of influenza vaccine reduced RSV-hospitalisations, especially in those <2 years with a rate reduction of 2.27 per 1000 (95 % CI: −3.26; −1.28), and a smaller rate reduction of 0.53 per 1000 (95 % CI: −1.04; −0.02) in those 2–7 years. Over the 5-year period (2008–2013), the state-funded preschool-influenza vaccine program resulted in 1,193 fewer RSV-hospitalisations. Of these, 793 (67 %) were in young children <2 years. ConclusionsTo our knowledge, this is the first analysis utilising an IV estimation strategy on a population level to assess the causal impact of seasonal influenza vaccine on risk of RSV-hospitalisations. We estimated a small protective effect that warrants further investigation.

Seasonality in Respiratory Syncytial Virus Hospitalizations and Immunoprophylaxis

This cross-sectional study assesses whether current guidance on respiratory syncytial virus supports the current epidemiologic characteristics, treatment, and hospitalization patterns in respiratory syncytial virus.

Understanding the age spectrum of respiratory syncytial virus associated hospitalisation and mortality burden based on statistical modelling methods: a systematic analysis

BackgroundStatistical modelling studies based on excess morbidity and mortality are important for understanding RSV disease burden for age groups that are less frequently tested for RSV. We aimed to understand the full age spectrum of RSV morbidity and mortality burden based on statistical modelling studies, as well as the value of modelling studies in RSV disease burden estimation.MethodsThe databases Medline, Embase and Global Health were searched to identify studies published between January 1, 1995, and December 31, 2021, reporting RSV-associated excess hospitalisation or mortality rates of any case definitions using a modelling approach. All reported rates were summarised using median, IQR (Interquartile range) and range by age group, outcome and country income group; where applicable, a random-effects meta-analysis was conducted to combine the reported rates. We further estimated the proportion of RSV hospitalisations that could be captured in clinical databases.ResultsA total of 32 studies were included, with 26 studies from high-income countries. RSV-associated hospitalisation and mortality rates both showed a U-shape age pattern. Lowest and highest RSV acute respiratory infection (ARI) hospitalisation rates were found in 5–17 years (median: 1.6/100,000 population, IQR: 1.3–18.5) and < 1 year (2235.7/100,000 population, 1779.1–3552.5), respectively. Lowest and highest RSV mortality rates were found in 18–49 years (0.1/100,000 population, 0.06–0.2) and ≥ 75 years (80.0/100,000 population, 70.0–90.0) for high-income countries, respectively, and in 18–49 years (0.3/100,000 population, 0.1–2.4) and < 1 year (143.4/100,000 population, 143.4–143.4) for upper-middle income countries. More than 70% of RSV hospitalisations in children < 5 years could be captured in clinical databases whereas less than 10% of RSV hospitalisations could be captured in adults, especially for adults ≥ 50 years. Using pneumonia and influenza (P&I) mortality could potentially capture half of all RSV mortality in older adults but only 10–30% of RSV mortality in children.ConclusionsOur study provides insights into the age spectrum of RSV hospitalisation and mortality. RSV disease burden using laboratory records alone could be substantially severely underreported for age groups ≥ 5 years. Our findings confirm infants and older adults should be prioritised for RSV immunisation programmes.Trial registrationPROSPERO CRD42020173430.

280-LB: Efficacy of a Respiratory Syncytial Virus (RSV) Prefusion F Protein Vaccine (RSVPreF3 OA) in Older Adults with Preexisting Medical Conditions

Background: Adults with diabetes and other conditions are at increased risk of severe RSV disease and hospitalization. In a phase 3 placebo-controlled study (NCT04886596) in adults ≥60 years, RSVPreF3 OA showed 82.6% vaccine efficacy (VE) against RSV-related lower respiratory tract disease (RSV-LRTD) and 71.7% against RSV-related acute respiratory infection (RSV-ARI). We assessed VE among participants with different BMI and with selected pre-existing metabolic or endocrine conditions (eg, diabetes) that increase the risk of severe RSV disease. Methods: Adults ≥60 years were 1:1 randomized to receive 1 dose of RSVPreF3 OA or placebo before the RSV season. VE against first occurrence of RSV-LRTD and RSV-ARI was calculated for different subgroups (Table). Results: In total, 24,966 participants received RSVPreF3 OA (12,467) or placebo (12,499). Of these, 25.7% (RSVPreF3 OA) and 25.9% (placebo) had ≥1 metabolic or endocrine condition (22.9% diabetes). Mean BMI in both groups was 29.1 kg/m2. In participants with overweight/obesity, VE was 85.6% (RSV-LRTD) and 76.3% (RSV-ARI). In those with ≥1 metabolic or endocrine condition, VE was 100% (RSV-LRTD) and 79.4% (RSV-ARI) (Table). Conclusion: RSVPreF3 OA is highly efficacious against RSV-LRTD and RSV-ARI in adults ≥60 years with overweight/obesity and in those with ≥1 metabolic or endocrine condition. Disclosure R. G. Feldman: Research Support; GSK, Speaker's Bureau; Amgen Inc., GSK. V. Hulstroem: Employee; GlaxoSmithKline plc., Stock/Shareholder; GlaxoSmithKline plc. R. Antonelli incalzi: None. K. Steenackers: Employee; Johnson &amp; Johnson Medical Devices Companies. D. Lee: None. L. Fissette: Employee; GlaxoSmithKline plc., Stock/Shareholder; GlaxoSmithKline plc. M. David: Employee; GlaxoSmithKline plc., Stock/Shareholder; GlaxoSmithKline plc. C. Maréchal: Employee; GlaxoSmithKline plc., Stock/Shareholder; GlaxoSmithKline plc. L. Kostanyan: None. M. Van der wielen: Employee; GlaxoSmithKline plc. Funding GlaxoSmithKline Biologicals SA

524-P: Knowledge, Attitudes, and Perceptions of Respiratory Syncytial Virus (RSV) among U.S. Adults with Diabetes

Rationale: Risk of complications and severe outcomes from respiratory syncytial virus (RSV) infection is increased in older adults and adults with certain chronic conditions in the United States (US). Among adults with diabetes, RSV hospitalization rates are ~2.4-11.4 times higher vs. adults without diabetes. Despite this burden, there are no previous evaluations of RSV knowledge, attitudes, and perceptions (KAP) among adults with diabetes. This study assessed RSV-related KAP among adults at risk of RSV infection, including adults with diabetes. Methods: A cross-sectional, web-based survey of US adults aged 18-89 years was administered between May-June 2022 to evaluate respiratory infection and RSV-related KAP. Target survey sample sizes included ≥200 adults from 4 subgroups: adults aged 18-59 years with diabetes, ≥1 chronic pulmonary, or ≥1 cardiac condition, as well as older adults aged 60-89 years. Results: A total of 339 adults aged 18-89 years with diabetes completed the survey (41.0%; n=339/827). Among those with diabetes, 78.2% (n=265/339) reported being knowledgeable about respiratory infections, although &amp;gt;60% (n=206/339) had never heard of RSV. Among those aware of RSV, 69.9% (n=93/133) rarely consider RSV as a cause of their cold/flu-like symptoms. Examples of identified knowledge gaps included respiratory infection causes (bacterial vs. viral), RSV seasonality, frequency of occurrence, and symptoms. Between 28.6-60.4% perceived that their risk of contracting RSV was lower than for 5 other respiratory infections, but only 19.6-38.9% perceived a lower severity of RSV. Conclusions: This study highlights key RSV knowledge gaps and attitudes/perceptions among US adults with diabetes. Given the increased risk of severe RSV-related outcomes among these adults, findings can be used by health care providers to inform their patient education efforts related to RSV disease awareness. Funding: GlaxoSmithKline Biologicals SA (study: 218693/HE-RSV-004 BOD) Disclosure E.La: Employee; GlaxoSmithKline plc., Stock/Shareholder; GlaxoSmithKline plc. S.Bunniran: Consultant; GlaxoSmithKline plc., Stock/Shareholder; Humana. D.Garbinsky: None. M.Reynolds: None. S.Poston: Employee; GlaxoSmithKline plc. L.Harrington: Employee; GlaxoSmithKline plc.

Estimating the incidence of first RSV hospitalization in children born in Ontario, Canada.

Respiratory syncytial virus (RSV) contributes significantly to morbidity in children, placing substantial burdens on health systems, thus RSV vaccine development and program implementation are a public health priority. More data on burden are needed by policymakers to identify priority populations and formulate prevention strategies as vaccines are developed and licensed. Using health administrative data, we calculated incidence rates of RSV hospitalization in a population-based birth cohort of all children born over a six-year period (May 2009 - June 2015) in Ontario, Canada. Children were followed until their first RSV hospitalization, death, 5 th birthday, or the end of the study period (June 2016). RSV hospitalizations were identified using a validated algorithm based on International Classification of Diseases, 10 th Revision, and/or laboratory-confirmed outcomes. We calculated hospitalization rates by various characteristics of interest, including calendar month, age groups, sex, comorbidities, and gestational age. The overall RSV hospitalization rate for children <5 years was 4.2 per 1,000 person-years (PY) with a wide range across age groups (from 29.6 to 0.52 per 1000PY in children aged 1 month and 36-59 months, respectively). Rates were higher in children born at a younger gestational age (23.2 per 1000PY for those born at <28 weeks versus 3.9 per 1000PY born at ≥37 weeks); this increased risk persisted as age increased. While the majority of children in our study had no comorbidities, rates were higher in children with comorbidities. For all age groups, rates were highest between December and March. Our results confirm the high burden of RSV hospitalization and highlight young infants are at additional risk, namely premature infants. These results can inform prevention efforts.

Changes in hospitalizations and emergency department respiratory viral diagnosis trends before and during the COVID-19 pandemic in Ontario, Canada.

Population-level surveillance systems have demonstrated reduced transmission of non-SARS-CoV-2 respiratory viruses during the COVID-19 pandemic. In this study, we examined whether this reduction translated to reduced hospital admissions and emergency department (ED) visits associated with influenza, respiratory syncytial virus (RSV), human metapneumovirus, human parainfluenza virus, adenovirus, rhinovirus/enterovirus, and common cold coronavirus in Ontario. Hospital admissions were identified from the Discharge Abstract Database and exclude elective surgical admissions and non-emergency medical admissions (January 2017-March 2022). Emergency department (ED) visits were identified from the National Ambulatory Care Reporting System. International Classification of Diseases (ICD-10) codes were used to classify hospital visits by virus type (January 2017-May 2022). At the onset of the COVID-19 pandemic, hospitalizations for all viruses were reduced to near-trough levels. Hospitalizations and ED visits for influenza (9,127/year and 23,061/year, respectively) were nearly absent throughout the pandemic (two influenza seasons; April 2020-March 2022). Hospitalizations and ED visits for RSV (3,765/year and 736/year, respectively) were absent for the first RSV season during the pandemic, but returned for the 2021/2022 season. This resurgence of hospitalizations for RSV occurred earlier in the season than expected, was more likely among younger infants (age ≤6 months), more likely among older children (aged 6.1-24 months), and less likely to comprise of patients residing in higher areas of ethnic diversity (p<0.0001). During the COVID-19 pandemic, there was a reduced the burden of other respiratory infections on patients and hospitals. The epidemiology of respiratory viruses in the 2022/23 season remains to be seen.

Leveraging Influenza Virus Surveillance From 2012 to 2015 to Characterize the Burden of Respiratory Syncytial Virus Disease in Canadian Adults ≥50 Years of Age Hospitalized With Acute Respiratory Illness.

Respiratory syncytial virus (RSV) disease in older adults is undercharacterized. To help inform future immunization policies, this study aimed to describe the disease burden in Canadian adults aged ≥50 years hospitalized with RSV. Using administrative data and nasopharyngeal swabs collected from active surveillance among adults aged ≥50 years hospitalized with an acute respiratory illness (ARI) during the 2012-2013, 2013-2014, and 2014-2015 influenza seasons, RSV was identified using a respiratory virus multiplex polymerase chain reaction test to describe the associated disease burden, incidence, and healthcare costs. Of 7797 patients tested, 371 (4.8%) were RSV positive (2.2% RSV-A and 2.6% RSV-B). RSV prevalence varied by season from 4.2% to 6.2%. Respiratory virus coinfection was observed in 11.6% (43/371) of RSV cases, with influenza A being the most common. RSV hospitalization rates varied between seasons and increased with age, from 8-12 per 100 000 population in adults aged 50-59 years to 174-487 per 100 000 in adults aged ≥80 years. The median age of RSV cases was 74.9 years, 63.7% were female, and 98.1% of cases had ≥1 comorbidity. Among RSV cases, the mean length of hospital stay was 10.6 days, 13.7% were admitted to the intensive care unit, 6.4% required mechanical ventilation, and 6.1% died. The mean cost per RSV case was $13 602 (Canadian dollars) but varied by age and Canadian province. This study adds to the growing literature on adult RSV burden by showing considerable morbidity, mortality, and healthcare costs in hospitalized adults aged ≥50 years with ARIs such as influenza.

Burden of Respiratory Syncytial Virus in the European Union: estimation of RSV-associated hospitalizations in children under 5 years.

No overall estimate of respiratory syncytial virus (RSV)-associated hospitalizations in children aged under 5 years has been published for the European Union (EU). We aimed to estimate the RSV hospitalization burden in children aged under 5 years in EU countries and Norway, by age group. We collated national RSV-associated hospitalization estimates calculated using linear regression models via the RESCEU project for Denmark, England, Finland, Norway, the Netherlands, and Scotland, 2006-2018. Additional estimates were obtained from a systematic review. Using multiple imputation and nearest neighbor matching methods, we estimated overall RSV-associated hospitalizations and rates in the EU. Additional estimates for 2 countries (France and Spain) were found in the literature. In the EU, an average of 245 244 (95% confidence interval [CI], 224 688-265 799) yearly hospital admissions with a respiratory infection per year were associated with RSV in children aged under 5 years, with most cases occurring among children aged under 1 year (75%). Infants aged under 2 months represented the most affected group (71.6 per 1000 children; 95% CI, 66.6-76.6). Our findings will help support decisions regarding prevention efforts and represent an important benchmark to understand changes in the RSV burden following the introduction of RSV immunization programs in Europe.