Respiratory syncytial virus (RSV) is an important cause of severe respiratory disease in older adults. Understanding the disease burden is crucial for guiding vaccination policy and raising disease awareness. We estimated the burden of RSV hospitalizations and deaths in adults in five middle-income countries: Argentina, Brazil, Chile, Mexico, and Malaysia. Hospital discharge and death statistics due to any respiratory disease (ICD-10 codes: J00–99) from 2010 to 2022 were obtained. The RSV attributable burden on hospitalizations and deaths by age group was determined for 2019 using previously published estimates. Latin American countries showed distinct annual peaks in respiratory-related hospitalizations and deaths during winter months that were absent in Malaysia. Among ≥20-year-olds in 2019, there were 14,604 RSV-attributable hospitalizations nationally in Argentina, 44,323 in Brazil, 4529 in Chile, 7416 in Malaysia, and 8651 in Mexico, and 60–74% in ≥65-year-olds. There were also 3518 RSV-attributable deaths in Argentina, 9115 in Brazil, 801 in Chile, 704 in Malaysia, and 3806 in Mexico 79–88% in ≥65-year-olds. Incidences of RSV-attributable hospitalizations in ≥75-year-olds ranged between 256.3 and 294.3 per 100,000 population, and deaths between 33.6 and 112.9 per 100,000 population. RSV is associated with a substantial disease burden beyond pediatric age groups, and preventive vaccines could have a major impact on this burden, especially in older adults.

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. Graphical Plain Language Summary

Introduction Limited data are available on the epidemiology and clinical burden of respiratory syncytial virus (RSV) among adults with underlying medical or immunocompromising conditions (“high-risk adults”) and ≥ 50-year-old adults in developing countries. Methods To better understand the impact of RSV in these populations, a systematic literature review of articles published from the year 2000 onward reporting RSV data among high-risk 18–59-year-old adults and ≥ 50-year-old adults in low, lower-middle, upper-middle, and selected high-income countries was undertaken. Searches were run on Medical Literature Analysis and Retrieval System Online (MEDLINE) and Excerpta Medica DataBASE (EMBASE), and were supplemented by additional searches (e.g., congress abstracts, gray literature). A combination of artificial intelligence models was used for title/abstract screening. After this, full-text screening of inclusions was conducted, followed by prioritization. Results Overall, 77 citations were selected for final inclusion. Of these, 69 reported outcomes related to RSV epidemiology and clinical burden, and are reported in this article. There were limited data on RSV incidence, prevalence, disease severity, and subtype distribution. Adequate evidence was available for RSV positivity among patients with respiratory illnesses, seasonality, complications, and mortality. Incidence in ≥ 65-year-olds was in the range of ~10–178 episodes per 1000 person-years across studies. Ranges for RSV positivity among patients with different underlying respiratory conditions were 1.5–31.9% and 0–9.1%, in high-risk and ≥ 50-year-old adults, respectively. Case fatality rates of up to 15.2% and 27.0% were reported across studies for high-risk and > 60-year-old adults, respectively. Conclusions Overall, there were considerable evidence gaps for RSV epidemiology among high-risk and ≥ 50-year-old adults in developing countries. However, available data indicate a substantial negative health impact of RSV on these populations, highlighting the need for further data generation.

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. Graphical Abstract