The Hidden Burden of RSV: Hospitalization Trends Among Older Adults

Recent research highlights the significant underreporting of Respiratory Syncytial Virus (RSV) cases among older adults, revealing a pressing need for enhanced surveillance and diagnostic measures in healthcare systems across Europe. A study published in the journal Eurosurveillance examines hospitalization trends for RSV in adults from six European countries before and during the COVID-19 pandemic, emphasizing the importance of acknowledging the virus's impact on this vulnerable population.

RSV, primarily recognized for its effects on infants and young children, has emerged as a serious health concern for older adults, particularly those with pre-existing health conditions. According to Dr. Liji Thomas, an OB-GYN and the author of the study, “Emerging evidence indicates that RSV accounts for unexpectedly high hospitalization rates among older adults, especially those who are immunocompromised or have chronic health issues.” This study aims to quantify that burden and to advocate for improved public health responses.

The study utilized data from national hospital registries in five countries—Finland, Denmark, the Netherlands, England, and Spain—along with a prospective dataset from the Valencia region of Spain. It tracked RSV-related hospitalizations during the years 2016 to 2023, excluding data from 2019/20 and 2020/21 due to pandemic-related disruptions. The findings suggest that RSV-coded admissions underestimate actual cases by as much as 4.3 times, highlighting a critical gap in current healthcare surveillance systems.

Hospitalization rates among older adults have shown a concerning upward trend. For instance, the study found that adults aged 85 and older had the highest hospitalization rates, with Finland reporting up to 445 RSV-confirmed hospitalizations per 100,000 person-years during the peak in the 2017/18 season. Conversely, Denmark and Spain-Valencia reported significantly lower rates, often fewer than 10 cases per 100,000 person-years across all age groups.

Despite the low incidence of confirmed cases, the study underscores the critical need for routine laboratory testing and better diagnostic protocols. “The average underestimate factor for RSV-coded admissions compared to laboratory-confirmed cases was 1.9, ranging from 1.1 to 4.3 across countries,” Dr. Thomas noted. This discrepancy necessitates more sensitive diagnostic measures to ensure accurate reporting and effective public health planning.

Moreover, the impact of the COVID-19 pandemic on RSV transmission dynamics remains a significant factor. During the pandemic years, RSV admissions fell dramatically, with Finland experiencing a complete cessation of reported cases in 2020/21. This decline was attributed to public health measures aimed at controlling the spread of COVID-19, which inadvertently reduced RSV transmission as well. However, reports indicated a 61% increase in RSV-coded admissions among the elderly in England, suggesting that while overall cases decreased, the burden on healthcare systems remained critical for older populations.

The study also revealed concerning statistics about Intensive Care Unit (ICU) admissions and mortality rates among RSV patients. ICU admissions were notably higher in patients younger than 75 before the pandemic, a trend that shifted as the severity of cases appeared to decrease during the pandemic. In the 85-plus age group, case fatality ratios reached as high as 17.6% in some countries, emphasizing the mortality risk associated with RSV in older adults.

In conclusion, the findings from this comprehensive study highlight the urgent need for improved surveillance systems and diagnostic measures for RSV in older populations. Dr. Thomas advocates for coordinated European efforts to enhance testing capabilities and ensure consistent coding practices across nations. “This study lays the groundwork for future research and surveillance efforts aimed at mitigating the impact of RSV on vulnerable populations,” she stated. As healthcare systems grapple with the ongoing effects of the pandemic, addressing the underreported burden of RSV has never been more critical.