Respiratory Syncytial Virus Hospitalization Research Articles

Respiratory Syncytial Virus Outbreak in Infants and Young Children during COVID-19 Pandemic in Taiwan

Respiratory syncytial virus (RSV) is a major burden of disease in babies and young children, including hospitalizations and deaths. RSV is a seasonal disease that peaks when temperatures decrease in temperate zones and humidity increases in tropical regions. Existing research reveals that RSV hospitalization activity is year-round in Taiwan, which is a subtropical region with small peaks in spring and fall. The monthly distribution and COVID-19 pandemic impact were unclear. The aim of this study was to investigate Taiwan's RSV hospitalization seasonality and the COVID-19 pandemic effects. The National Health Insurance Database and Death Registration Files from the Center for Health and Welfare Data Science Center were connected to birth data for this study. RSV hospitalization (RSVH) in infants aged 0-1 years ranged from 0.9518% (2009) to 1.7113% (2020), substantially higher than in children aged 1-5. Most years had 2 or 3 RSV epidemic seasons in 0-5-year-olds over the 13-year follow-up. RSVH incidence was low until the autumn of 2020, when a major rise occurred after September and lasted until December 2020. We detected RSVH peaks in February-May and July-August. The 2020 RSV outbreak was found at the end of 2020.

Adjusting for Case Under-Ascertainment in Estimating RSV Hospitalisation Burden of Older Adults in High-Income Countries: a Systematic Review and Modelling Study.

Previous studies suggest diagnostic testing characteristics (i.e. variations in clinical specimens and diagnostic tests) can contribute to underestimation of RSV disease burden. We aimed to improve the understanding of RSV hospitalisation burden in older adults (aged ≥ 65years) in high-income countries through adjusting for case under-ascertainment. We conducted a systematic review to include data on RSV-associated acute respiratory infection (ARI) hospitalisation burden in older adults in high-income countries. To adjust for case under-ascertainment, we developed a two-step framework that incorporated empirical data on the RSV detection proportion of different clinical specimens and testing approaches as well as their statistical uncertainty. We estimated the unadjusted and adjusted RSV-associated hospitalisation burden through multilevel random-effects meta-analysis. We further explored RSV-associated in-hospital mortality burden. We included 12 studies with eligible RSV hospitalisation burden data. We estimated that pooled unadjusted hospitalisation rate was 157 per 100,000 (95%CI 98-252) for adults aged ≥ 65years; the rate was adjusted to 347 per 100,000 (203-595) after accounting for under-ascertainment. The adjusted rate could be translated into 787,000 (460,000-1,347,000) RSV-associated hospitalisations in high-income countries in 2019, which was about 2.2 times the unadjusted estimate. Stratified analysis by age group showed that the adjusted rate increased with age, from 231 per 100,000 in adults aged 65-74years to 692 per 100,000 in adults aged > 85years. The in-hospital case fatality ratio of RSV was 6.1% (3.3-11.0) and the total RSV-associated in-hospital deaths in high-income countries in 2019 could be between 22,000 and 47,000. This study improves the understanding of RSV-associated hospitalisation burden in older adults and shows that the true RSV-associated hospitalisation burden could be 2.2 times what was reported in existing studies. This study has implications for calculating the benefit of interventions to treat and prevent RSV-associated disease.

Quantifying changes in respiratory syncytial virus-associated hospitalizations among children in Texas during COVID-19 pandemic using records from 2006 to 2021.

To quantify changes on RSV- associated hospitalizations during COVID-19 pandemic, among children four years of age or younger at the state and county levels of Texas using routinely acquired hospital admission records. We used the Texas Public Use Data Files (PUDF) of the Department of State Human Services (DSHS) to obtain hospital admissions and healthcare outcomes from 2006 to 2021. We used the 2006-2019 period to estimate a long-term temporal trend and predict expected values for 2020-2021. Actual and predicted values were used to quantify changes in seasonal trends of the number of hospital admissions and mean length of hospital stay. Additionally, we calculated hospitalization rates and assessed their similarity to rates reported in the RSV Hospitalization Surveillance Network (RSV-NET). An unusually low number of hospitalizations in 2020 was followed by an unusual peak in the third quarter of 2021. Hospital admissions in 2021 were approximately twice those in a typical year. The mean length of hospital stay typically followed a seasonal trend before COVID-19, but increased by a factor of ∼6.5 during the pandemic. Spatial distribution of hospitalization rates revealed localized healthcare infrastructure overburdens during COVID-19. RSV associated hospitalization rates were, on average, two times higher than those of RSV-NET. Hospital admission data can be used to estimate long-term temporal and spatial trends and quantify changes during events that exacerbate healthcare systems, such as pandemics. Using the mean difference between hospital rates calculated with hospital admissions and hospital rates obtained from RSV-NET, we speculate that state-level hospitalization rates for 2022 could be at least twice those observed in the two previous years, and the highest in the last 17 years.

Respiratory Syncytial Virus in Veneto Region: Analysis of Hospital Discharge Records from 2007 to 2021

Respiratory Syncytial Virus (RSV) is a known cause of acute lower respiratory infections in infants and young children. The present study aims to analyze the temporal trends and characteristics of hospitalization related to RSV in the Veneto region (Italy) in the period between 2007 and 2021. The analysis is performed on all the hospital discharge records (HDRs) of public and accredited private hospitals corresponding to hospitalizations occurring in the Veneto region (Italy). HDRs are considered if they included at least one of the following ICD9-CM codes: 079.6-Respiratory Syncytial Virus (RSV); 466.11-acute bronchiolitis due to RSV; and 480.1-pneumonia due to RSV. Total annual cases, sex, and age-specific rates and trends are evaluated. Overall, an increasing trend in the number of hospitalizations due to RSV was observed between 2007 and 2019, with a slight drop in RSV seasons 2013-2014 and 2014-2015. From March 2020 to September 2021, almost no hospitalization was registered, but in the last quarter of 2021, the number of hospitalizations reached its highest value in the series. Our data confirm the preponderance of RSV hospitalizations in infants and young children, the seasonality of RSV hospitalizations, and acute bronchiolitis as the most frequent diagnosis. Interestingly, the data also show the existence of a significant burden of disease and a non-negligible number of deaths also in older adults. The present study confirms RSV is associated with high rates of hospitalization in infants and sheds light on the burden in the 70+ age group in which a considerable number of deaths was observed, as well as the parallelism with other countries, which is consistent with a wide underdiagnoses issue.

Comparison of the Canadian vs. the international risk scoring tool for respiratory syncytial virus prophylaxis in moderate-to-late preterm infants.

The study objective was to compare the Pediatric Investigators Collaborative Network on Infections in Canada risk scoring tool (CRST) that determines need for respiratory syncytial virus (RSV) prophylaxis in infants 33-35 weeks gestational age during the RSV season, with the newly developed international risk scoring tool (IRST). Children 33-35 weeks gestational age born during the 2018-2021 RSV seasons were prospectively identified following birth and scored with the validated CRST and IRST, that comprises seven and three variables respectively, into low- moderate- and high-risk groups that predict RSV-related hospitalization. Correlations between total scores on the two tools, and cut-off scores for the low-, moderate- and high-risk categories were conducted using the Spearman rank correlation. Over a period of 3 RSV seasons, 556 infants were scored. Total risk scores on the CRST and the IRST were moderately correlated (rs = 0.64, p < 0.001). A significant relationship between the risk category rank on the CRST and the risk category rank on the IRST (rs = 0.53; p < 0.001) was found. The proportion of infants categorized as moderate risk for RSV hospitalization by the CRST and IRST were 19.6% (n = 109) and 28.1% (n = 156), respectively. The IRST may provide a time-efficient scoring alternative to the CRST with three vs. seven variables, and it selects a larger number of infants who are at moderate risk for RSV hospitalization for prophylaxis. A cost-utility analysis is necessary to justify country-specific use of the IRST, while in Canada a cost comparison is necessary between the IRST vs. the currently approved CRST prior to adoption.

La profilassi dell’infezione da virus respiratorio sinciziale: dal palivizumab al nirsevimab

The Respiratory Syncytial Virus (RSV) is considered the leading cause of lower respiratory tract infections (LRTI) in children aged &lt; 2 years. In high-risk children, including preterm infants, or in children with bronchopulmonary dysplasia (BPD) and infants with congenital heart diseases (CHD), RSV infections may lead to severe consequences that often require hospitalizations. The typical seasonality of RSV is going through some changes and as consequence the healthcare management of serious infections is facing some difficulties. In this context and in light of the worldwide economic, political and healthcare debate around treatment of RSV infections, this article aims to inform physicians and healthcare professionals about evidence regarding the two drugs licensed for passive prophylaxis against RSV, namely palivizumab and nirsevimab. According to the 1998 IMpact study, palivizumab administration (5 monthly doses) was able to reduce the incidence of RSV hospitalizations in infants born preterm and in those with BPD. However, over the years, several studies found questionable cost-effectiveness evidence regarding the use of palivizumab in preterm infants born at ≥ 29 weeks of gestation. Differently from palivizumab, one single dose of nirsevimab is able to protect over an entire RSV season. This drug was able to reduce hospitalizations and medically attended RSV-associated LRTI in infants born preterm and without comorbidities, but none similar efficacy was found in reducing hospitalizations in healthy infants born at term (born at ≥ 35 weeks of gestation). As such, while future interventions in the clinical management of RSV infections and related consequences are warranted, new evidence about nirsevimab and palivizumab use will be essential to define which population will benefit the most from passive prophylaxis.

2209. RSV-associated Hospitalizations in Adults Aged ≥18 Years and the Impact of the COVID-19 Pandemic in the United States, October 2018 – February 2022

Abstract Background Respiratory syncytial virus (RSV) is a significant cause of hospitalizations in older adults and typically circulates during the fall and winter in the United States. The COVID-19 pandemic and implementation of nonpharmaceutical interventions (NPIs) including masking, improved handwashing, and social distancing likely impacted RSV circulation. To explore the pandemic’s impact on RSV seasonality and hospitalizations in adults aged ≥18 years, we analyzed laboratory-confirmed RSV-associated hospitalizations through the RSV Hospitalization Surveillance Network (RSV-NET) across four seasons. Methods RSV-NET is a population-based surveillance system that collects data on RSV-associated hospitalizations across 75 counties in 12 states. An RSV-NET case is a resident of a defined catchment area who tests positive for RSV through a clinician-ordered test within 14 days prior to or during hospitalization. Surveillance was conducted October–April for the 2018-19 and 2019-20 pre-pandemic seasons and October 2020–September 2021 (2020-21 season). Available data October 2021-February 2022 (ongoing 2021-22 season) are presented. Results 2,536, 3,195, 618, and 1,758 laboratory-confirmed hospitalizations were identified in adults ≥18 years in 2018-19, 2019-20, 2020-21, and 2021-22, respectively; case counts were 4.1 and 5.2 times higher in 2018-19 and 2019-20, respectively, than in 2020-2021. Hospitalizations peaked in January for pre-pandemic and 2021-22 seasons and in September for 2020-21 (Figure). For all years combined, 16.2%, 23.4%, 33.3%, and 27.1% of all RSV-associated hospitalizations were among those aged 18-49, 50-64, 65-79 and ≥80 years, respectively. Laboratory-confirmed RSV-associated hospitalizations in adults ≥18 years, October 2018 – February 2022 Conclusion Laboratory-confirmed RSV-associated hospitalizations in adults were lower during the 2020-21 and 2021-22 seasons compared with pre-pandemic seasons, with a marked change in seasonal patterns in 2020-21, likely because of NPIs implemented during the pandemic. Continued monitoring of RSV-associated hospitalizations will be critical to understand ongoing changes in RSV circulation that resulted from the COVID-19 pandemic and associated NPIs. Disclosures Evan J. Anderson, MD, GSK: Advisor/Consultant|GSK: Grant/Research Support|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Kentucky Bioprocessing, Inc: Data Safety Monitoring Board|MedImmune: Grant/Research Support|Medscape: Advisor/Consultant|Merck: Grant/Research Support|Micron: Grant/Research Support|NIH: Funding from NIH to conduct clinical trials of Moderna and Janssen COVID-19 vaccines|PaxVax: Grant/Research Support|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Regeneron: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant|Sanofi Pasteur: Grant/Research Support|Sanofi Pasteur: Data Adjudication and Data Safety Monitoring Boards|WCG and ACI Clinical: Data Adjudication Board Maya Monroe, MPH, CDC -Emerging Infections Program: Grant/Research Support.

94. Pooled analysis of nirsevimab resistance through 150 days post dose in preterm and term infants

Abstract Background Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection (LRTI) and hospitalization in infants. In two global pivotal placebo-controlled studies, nirsevimab, a monoclonal antibody to the RSV prefusion (F) protein with extended half-life, reduced medically attended (MA) RSV LRTI versus placebo throughout the RSV season (MELODY (Primary Cohort)/Study 3 (Proposed Dose) Pool, 79.5% efficacy). Here we summarize resistance analyses of all RT-PCR-confirmed RSV isolates from healthy term and preterm infants through 150 days post dose. Methods Infants were randomized 2:1 to receive one intramuscular injection of nirsevimab or placebo, prior to their first RSV season. RT-PCR-confirmed RSV isolates were reflexed for genotypic analyses of RSV F and phenotypic analyses of identified substitutions in a recombinant RSV neutralization susceptibility assay. Results In the pooled proposed dose analysis of Study 3 (50 mg nirsevimab if &amp;lt; 5 kg at dosing) and MELODY (50 or 100 mg nirsevimab if &amp;lt; 5 kg or ≥5 kg at dosing, respectively), no subject with MA RSV LRTI had an RSV isolate containing nirsevimab resistance-associated substitutions in either treatment group (nirsevimab, RSV A: 0/14 and RSV B: 0/5; placebo, RSV A: 0/35 and RSV B: 0/16). In Study 3 (50 mg nirsevimab if ≥5 kg at dosing), 2/18 subjects in the nirsevimab group and 0/20 subjects in the placebo group with MA RSV LRTI had an RSV isolate harbouring nirsevimab binding site substitutions I64T+K68E+I206M+Q209R (&amp;gt;447-fold) or N208S (&amp;gt;387-fold) that conferred reduced susceptibility to nirsevimab neutralization (nirsevimab, RSV A: 0/9 and RSV B: 2/9; placebo, RSV A: 0/10 and RSV B: 0/10). Subjects with RSV isolates harboring F protein sequence variations that maintained susceptibility to nirsevimab neutralization were balanced between treatment groups with no association with RSV disease severity. No subjects with non-protocol defined MA RSV LRTI cases or hospitalization due to any RSV respiratory illness had an RSV isolate conferring nirsevimab resistance. Conclusion Lack of nirsevimab resistance following immunization at the proposed dose supports efficacy and neutralization activity of nirsevimab against both RSV A and B strains throughout the RSV season. Disclosures Michael E. Abram, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Bahar Ahani, BSC, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds David E. Tabor, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Fiona Fernandes, PhD, AstraZeneca: Stocks/Bonds Deidre Wilkins, BSC, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Anastasia A. Aksyuk, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Kevin M. Tuffy, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Hong Ji, BSc, AstraZeneca: Stocks/Bonds Christine Blaze, BSc, AstraZeneca: Stocks/Bonds Tyler Brady, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Pamela Griffin, MD, AstraZeneca: Stocks/Bonds Amanda Leach, MD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Tonya L. Villafana, PhD, MPH, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Mark T. Esser, PhD, AstraZeneca: Stocks/Bonds.

116. Potential Clinical Impact of Respiratory Syncytial Virus (RSV) Vaccination in Older Adults in the United States

Abstract Background RSV causes acute respiratory disease (ARD), including severe lower respiratory tract disease (LRTD) in older adults, which can lead to hospitalization and death. Currently, there are no vaccines approved to prevent RSV disease. This study estimated the potential clinical impact of a hypothetical RSV vaccine over a 1-year time horizon in older adults aged ≥ 60 years. Methods A decision-analytic model was developed (Figure 1). A strategy was used where the entire US population aged ≥ 60 years was given a single dose vaccine with an assumed efficacy of 75% against ARD, LRTD, and LRTD-hospitalizations and compared to a population who did not receive a vaccine. Given the uncertainty around RSV hospitalization rates, 2 base-case scenarios were created: (1) hospitalization rates that used RSV-specific claim codes and (2) hospitalization rates increased by 49% to account for underreporting in claims; Table 1 shows key inputs. One-way sensitivity analyses were used to assess the impact of specific parameter estimates. Results The vaccine would prevent 1.8 million and 0.6 million upper respiratory disease and LRTD cases, respectively; Figure 2 shows additional results for both base-case scenarios. The number needed to vaccinate (NNV) to prevent 1 LRTD case is 119; the NNV to prevent 1 LRTD hospitalization or death ranges from 792 to 1180 and 10,452 to 15,574, respectively. Sensitivity analyses indicate that results mainly depend on vaccine efficacy, and incidence of ARD and LRTD. Conclusion There is substantial US public health benefit associated with utilization of an effective RSV vaccine in individuals ≥ 60 years of age to reduce RSV-associated morbidity and mortality; however, the magnitude of impact depends on RSV epidemiology, which is still being defined for older adults. Several model parameters were based on assumptions, and robust evidence generation is needed including the efficacy of an RSV vaccine, which is an important consideration in assessing the impact of vaccination in this age group. Disclosures Kelly Fust, MS, Quadrant Health Economics Inc: Contractor at Quadrant Health Economics Inc who was funded by Moderna to perform this study Michele Kohli, PhD, Quadrant Health Economics Inc: Shareholder at Quadrant Health Economics Inc who was funded by Moderna to perform this study|Quadrant Health Economics Inc: Stocks/Bonds Catherine A. Panozzo, PhD, Moderna, Inc.: Salary|Moderna, Inc.: Stocks/Bonds Philip Buck, PhD, MPH, Moderna, Inc.: Salary|Moderna, Inc.: Stocks/Bonds Parinaz Ghaswalla, PhD, Moderna, Inc.: Salary|Moderna, Inc.: Stocks/Bonds.

Changes following the Onset of the COVID-19 Pandemic in the Burden of Hospitalization for Respiratory Syncytial Virus Acute Lower Respiratory Infection in Children under Two Years: A Retrospective Study from Croatia.

To understand the changes in RSV hospitalization burden in children younger than two years following the onset of the COVID-19 pandemic, we reviewed hospital records of children with acute lower respiratory infection (ALRI) between January 2018 and June 2022 in Split-Dalmatia County, Croatia. We compared RSV activity, age-specific annualized hospitalization rate, and disease severity between pre-COVID-19 and COVID-19 periods. A total of 942 ALRI hospital admissions were included. RSV activity remained low for the typical RSV epidemic during 2020-2021 winter. An out-of-season RSV resurgence was observed in late spring and summer of 2021. Before the COVID-19 pandemic, the annualized hospitalization rate for RSV-associated ALRI was 13.84/1000 (95% CI: 12.11-15.76) and highest among infants under six months. After the resurgence of RSV in the second half of 2021, the annualized hospitalization rate for RSV-associated ALRI in children younger than two years returned to the pre-pandemic levels with similar age distribution but a statistically higher proportion of severe cases. RSV immunization programs targeting protection of infants under six months of age are expected to remain impactful, although the optimal timing of administration would depend on RSV seasonality that has not yet been established in the study setting since the onset of the COVID-19 pandemic.

Respiratory Syncytial Virus Pediatric Hospitalization in the COVID-19 Era

Respiratory syncytial virus (RSV) globally affects the population, mainly young children, potentially causing hospitalization. During the COVID-19 pandemic, non-pharmacological measures interfered with the circulation of most respiratory viruses. Then, with the discontinuation of restrictive measures, a new scenario appeared. With this scoping review, we want to globally explore whether the RSV paediatric hospitalization rate was influenced by COVID-19. This scoping review was performed according to PRISMA guidelines on PubMed using the Mesh terms "Respiratory Syncytial Viruses"[Mesh] AND "COVID-19"[Mesh] OR "SARS-CoV-2"[Mesh]. Among them, we identified studies pertaining to children and adolescents up to 18 years old hospitalized for RSV, including 18 records in the revision. With the onset of the COVID-19 pandemic, a drastic reduction in RSV hospitalization among the pediatric population in 2020-2021 season has been observed in the Northern and Southern hemispheres. After the relaxing of restrictive measures, unexpected outbreaks happened, leading to increased hospitalization and occupation of pediatric intensive care units.

Human Respiratory Syncytial Virus Infections among Hospitalized Children in Poland during 2010-2020: Study Based on the National Hospital Registry.

Human respiratory syncytial virus (RSV) is responsible for infections mainly affecting the lower respiratory tract in infants and young children after the first exposure. The aim of the study is to show up-to-date information on RSV hospitalization cases in Poland in children aged &lt; 5 years. A retrospective, population-based study was conducted using data from hospital discharge records of patients hospitalized from 2010-2020. The study group consisted of 57,552 hospitalizations of RSV children. The mean and median ages were 232 (95% CI: 230-234) and 132 (IQR 63-271) days. The mean annual hospitalization rate for patients with RSV infection was estimated to be 267.5 per 100,000, and the highest was observed in children &lt; 1 year (1132.1 per 100,000). The mean annual hospitalization rate was significantly higher in patients living in urban than rural regions (p &lt; 0.001). A statistically significant increase in the number of hospitalizations was observed (p &lt; 0.0001) during the analyzed period. The seasonal pattern was found with the highest rates of hospitalizations in the January-March period. The increasing RSV hospitalization rate requires further research and may be the basis for urgent healthcare measures. The results may be helpful in comparative analyses in the European and global context.

Real-World Studies of Respiratory Syncytial Virus Hospitalizations among Moderate/Late Preterm Infants Exposed to Passive Immunoprophylaxis with Palivizumab.

This article aims to assess the real-world effectiveness of palivizumab immunoprophylaxis against respiratory syncytial virus (RSV)-associated hospitalization (RSVH) rates in otherwise healthy moderate/late preterm infants and discuss the role of palivizumab in preventing acute and long-term outcomes. We identified studies in the PubMed and Embase databases that reported patient-level data on (1) exposure to palivizumab in preterm infants born between 29 and 35 weeks of gestational age (or subsets within this range) ≤ 2 years of chronological age, and (2) the outcome of RSVH. Six studies assessed RSVH in infants this gestational age who had been exposed or not to palivizumab and reported patient-level data. Exposure was associated with a reduction in RSVH rates that was comparable to the reduction seen in controlled clinical trials (weighed mean 4.0-fold reduction). RSV immunoprophylaxis in preterm infants within 29 to 35 weeks of gestational age is associated with a considerably lower burden of RSVH. KEY POINTS: · RSV is the leading cause of lower respiratory tract infection hospitalization in infants.. · Palivizumab prevents RSVH in a real-world scenario.. · Immunoprophylaxis should be used in high-risk infants..

Predicted effectiveness of vaccines and extended half-life monoclonal antibodies against RSV hospitalizations in children

Several vaccines and extended half-life monoclonal antibodies (mAbs) against respiratory syncytial virus (RSV) have shown promise in clinical trials. We used age-structured transmission models to predict the possible impact of various RSV prevention strategies including maternal immunization, live-attenuated vaccines, and long-lasting mAbs. Our results suggest that maternal immunization and long-lasting mAbs are likely to be highly effective in preventing RSV hospitalizations in infants under 6 months of age, averting more than half of RSV hospitalizations in neonates. Live-attenuated vaccines could reduce RSV hospitalizations in vaccinated age groups and are also predicted to have a modest effect in unvaccinated age groups because of disruptions to transmission. Compared to year-round vaccination, a seasonal vaccination program at the country level provides at most a minor advantage regarding efficiency. Our findings highlight the substantial public health impact that upcoming RSV prevention strategies may provide.

Estimated incidence of respiratory hospitalizations attributable to RSV infections across age and socioeconomic groups

BackgroundSurveillance for respiratory syncytial virus (RSV) likely captures just a fraction of the burden of disease. Understanding the burden of hospitalizations and disparities between populations can help to inform upcoming RSV vaccine programs and to improve surveillance.MethodsWe obtained monthly age-, ZIP code- and cause-specific hospitalizations in New York, New Jersey, and Washington from the US State Inpatient Databases (2005–2014). We estimated the incidence of respiratory hospitalizations attributable to RSV by age and by socioeconomic status using regression models. We compared the estimated incidence and the recorded incidence (based on ICD9-CM) of RSV hospitalizations to estimate the under-recorded ratio in different subpopulations.ResultsThe estimated annual incidence of respiratory hospitalizations due to RSV was highest among infants < 1 year of age with low socioeconomic status (2800, 95% CrI [2600, 2900] per 100,000 person-years). We also estimated a considerable incidence in older adults (≥ 65 years of age), ranging from 130 to 960 per 100,000 person-years across different socioeconomic strata. The incidence of hospitalization recorded as being due to RSV represented a significant undercount, particularly in adults. Less than 5% of the estimated RSV hospitalizations were captured for those ≥ 65 years of age.ConclusionsRSV causes a considerable burden of hospitalization in young children and in older adults in the US, with variation by socioeconomic group. Recorded diagnoses substantially underestimate the incidence of hospitalization due to RSV in older adults.

Characteristics of Respiratory Syncytial Virus versus Influenza Infection in Hospitalized Patients of Peru: A Retrospective Observational Study.

Respiratory syncytial virus (RSV) and influenza infections are important causes of respiratory illness associated with hospitalizations in children in Peru; however, comparisons of RSV and influenza hospitalization across all age groups are not available in Peru. Therefore, we conducted an observational, retrospective study between May 2015 and October 2021 using hospitalization from RSV and influenza infection data obtained from SUSALUD (open data) in Peru to compare the baseline characteristics of sex, age, region, and infection type. For the study, 2696 RSV-infected and 1563 influenza-infected hospitalized patients from different age groups were included. Most hospitalizations from RSV infection and the influenza virus occurred in children <5 years of age (86.1% vs. 32.2%, respectively). Compared with influenza infection, RSV infection was less likely to occur in individuals ≥5 years of age (adjusted odds ratio (aOR) = 0.07; 95% confidence interval (CI), 0.06–0.08; p < 0.0001; compared to <5 years of age), and more likely to occur in highlands (aOR = 1.75; 95% CI, 1.46–2.07; p < 0.0001, compared to coast region), and jungle region (aOR = 1.75; 95% CI, 1.27–2.41; p = 0.001, compared to coast region). Among the respiratory complications, RSV pneumonia was less likely to occur between different age groups (aOR = 0.29; 95% CI, 0.22–0.37; p < 0.0001, compared to <5 years of age), compared with influenza pneumonia. These findings on the RSV-hospitalization and its complications are helpful for health services planning and may increase awareness of the Peruvian population’s RSV and influenza disease burden.

Age-specific hospitalization risk of primary and secondary respiratory syncytial virus infection among young children

ObjectivesElucidating the infection dynamics that lead to severe respiratory syncytial virus (RSV) pneumonia and hospitalization among young children are critical. We explored the role of infection parity as well as age in months for RSV-associated hospitalization among young children in Japan. MethodsWe used a sequential transmission catalytic model to capture the transmission mechanisms of RSV among infants in an endemic state. We investigated data on the age-dependent seroprevalence and incidence rate of hospitalization in Japan, and jointly estimated the age-specific risk of hospitalization during primary RSV infection and relative risk of hospitalization during secondary infection in children aged <5 years. ResultsThe estimated risk of hospitalization with primary infection was 0.08 (95% CI: 0.05-0.14) in infants aged 0-2 months. The estimated relative risk of hospitalization owing to secondary infection was 0.18 (95% CI: 0.01-2.04). ConclusionOur simple models successfully captured the infection dynamics of RSV among young children in Japan. The age group of early infancy may be most vulnerable to infection and hospitalization, offering key insights into future vaccinations. The burden of hospitalization from secondary infection may be less important in young children.

Change in functional status associated with respiratory syncytial virus infection in hospitalized older adults.

Respiratory syncytial virus (RSV) causes severe respiratory illnesses in infants and older adults. Older adults are frequently hospitalized with RSV illness and may experience loss of function. This study evaluated longitudinal changes in function associated with RSV hospitalization in older adults. Adults ≥60 years hospitalized with laboratory-confirmed RSV were enrolled (N = 302). Demographics and comorbidities were collected. Functional status was assessed 2 weeks pre-hospitalization by recall, at enrollment, hospital discharge and 2, 4, and 6 months post-discharge using the Lawton-Brody Instrumental Activities of Daily Living (IADL) (scale 0-8) and Barthel ADL Index (scale 0-100). RSV-associated hospitalization resulted in acute functional loss. Median IADL (5 vs. 3, p &lt; 0.0001) and ADL (90 vs. 70, p &lt; 0.0001) scores decreased significantly from pre-hospitalization to admission and remained decreased at discharge. There were no statistically significant differences between pre-hospitalization and 2-, 4-, or 6-month scores. However, 33% and 32% of subjects experienced decreased 6-month IADL and ADL scores, respectively. Additionally, 14% required a higher level of care at discharge. When stratified by pre-hospitalization living situation, 6-month IADL scores declined significantly for those admitted from a skilled nursing facility (3 vs. 1, p = 0.001). In multivariate analysis, male sex and diabetes were associated with a 6-month decline in ADL score of ≥10. Older adults hospitalized with RSV demonstrate acute functional decline that may become prolonged. Pre-hospitalization living situation may predict patient outcomes. Further study is needed with hospitalized age-matched controls and refined measurement tools to better define the specific impact of RSV on function.

The role of birth month in the burden of hospitalisations for acute lower respiratory infections due to respiratory syncytial virus in young children in Croatia.

BackgroundBirth month was an important risk factor for respiratory syncytial virus (RSV) hospitalisation in infants. However, little is known about the role of birth month in RSV hospitalisation in finer age bands during infancy, which is relevant to strategies for RSV passive immunisations for infants. We aimed to understand the role of birth month in the burden of RSV-associated acute lower respiratory infection (ALRI) hospitalisation in finer age bands of the first year of life.MethodsIn this retrospective study, we analysed the hospitalisation records during 2014–19 at the University Hospital of Split, Split-Dalmatia County, Croatia. We estimated all-cause and RSV associated ALRI hospitalisation rates among children under five years, with a focus on infants by finer age band and birth month.ResultsWe included 1897 ALRI hospitalisations during the study period. Overall in children under five years, annual hospitalisation rate was 14.66/1000 (95% CI: 14.01–15.34) for all-cause ALRI, and was 7.56/1000 (95% CI: 6.83–8.34) for RSV-ALRI. RSV-ALRI hospitalisation rate was highest in infants aged 28 days–<3 months (61.15/1000, 95% CI: 52.91–70.31). Infants born in November, December and January (2–3 months before RSV peak) had the highest hospitalisation rates during infancy. Depending on the birth month of infants, the risk of RSV-ALRI hospitalisation peaked at different months of age; infants who were born in September had the highest RSV-ALRI hospitalisation rate at the age of 3–<6 months.ConclusionsOur study underlines the importance of birth month in planning RSV immunisation strategies for infants, and provides useful baseline data for effectiveness analysis of novel RSV prophylactic products.

Cost Savings Without Increased Risk of Respiratory Hospitalization for Preterm Children after the 2014 Palivizumab Policy Update.

Our objective was to compare rates of hospitalizations for respiratory illnesses in preterm and full-term (FT) children for 4 years before and after the 2014 update to the American Academy of Pediatrics (AAP) respiratory syncytial virus (RSV) immunoprophylaxis guidance, which restricted eligibility among infants born at 29 to 34 weeks in the first winter and all preterm infants in the second winter after neonatal discharge. We conducted pre-post and interrupted time series analyses on claims data from a commercial national managed care plan. We compared the number of RSV and all respiratory hospital admissions in the first and second RSV seasons after neonatal discharge among a cohort of preterm children, regardless of palivizumab status, in the 4 years before and after the implementation of the 2014 palivizumab eligibility change. A FT group was included for reference. The cohort included 821 early preterm (EP, <29 weeks), 4,790 moderate preterm (MP, 29-34 weeks), and 130,782 FT children. Palivizumab use after the policy update decreased among MP children in the first and second RSV seasons after neonatal discharge, without any change in the odds of hospitalization with RSV or respiratory illness. For the EP group, there was no change in the rate of palivizumab or the odds of hospitalization with RSV or respiratory illness after the policy update. For the FT group, there was a slight decrease in odds of hospitalization post-2014 after the policy update. The interrupted time series did not reveal any secular trends over time in hospitalization rates among preterm children. Following the policy change, there were cost savings for MP children in the first and second RSV seasons, when accounting for the cost of hospitalizations and the cost of palivizumab. Hospitalizations for RSV or respiratory illness did not increase, and cost savings were obtained after the implementation of the 2014 AAP palivizumab prophylaxis policy. · Palivizumab use decreased among children born moderate preterm (29 to34 weeks) after the 2014 palivizuamb policy update.. · There was no change in odds of hospitalization with respiratory syncitial virus or respiratory illness among preterm infants after the policy update when compared to before.. · There were cost savings, when accounting for the cost of hospitalizations and the cost of palivizumab, after the policy update among children born moderate preterm..