Respiratory syncytial virus (RSV) prophylaxis efforts for adults aged 60 and over in high-income countries are warranted, as recent research indicates higher-than-expected disease rates. This is among findings of a systematic review and meta-analysis published in Influenza and Other Respiratory Viruses.
Hypothesizing that RSV was under-recognized as a cause of illness among older adults, investigators sought to estimate the disease burden of RSV among adults at least 60 years of age in high-income countries through a systematic literature review and meta-analysis of articles published in English from January 2000 through the beginning of November 2021.
The investigators searched PubMed, Embase, and CINAHL databases, plus studies identified by citation search, grey literature, and the abstract booklet from the RSV Vaccine for the World 2021 conference. The review also included unpublished studies relaying the incidence of RSV-associated acute respiratory infection (ARI), hospitalizations as well as in-hospital case fatality rates (hCFR) in Canada, Europe, Japan, South Korea, and the US in adults at least 60 years of age. Retrospective studies were excluded. Most studies included estimated RSV-ARI and hospitalization attack rates.
The investigators performed a random effects meta-analysis on 21 studies (14 included data on attack rates, 8 on hospitalization rates, and 8 on hCFR of RSV-ARI). The pooled estimate for the RSV-ARI attack rate (number of cases) was 1.62% (95% CI, 0.84-3.08). The hospitalization attack rate (number of hospitalizations) was 0.15% (95% CI, 0.09-0.22). The hCFR (number of in-hospital deaths) was 7.13% (95% CI, 5.40-9.36). According to the investigators’ interpretation, this data indicated that in 2019, there were approximately 5.2 million RSV cases, 470,000 hospitalizations, and 33,000 in-hospital deaths related to RSV among adults at least 60 years of age in high-income countries.
Notably, this review “found a higher burden of RSV disease that previously described in the literature,” said investigators, noting that their point estimate for RSV-ARI attack rate of 16.2 per 1000 was well above the 6.7 per 1000 found in a previous 2015 systematic review by Shi and colleagues.
Study limitations include the wide range of RSV disease burden estimates between studies; insufficient data to stratify analyses by age group; lack of uniformity of age groups across studies; use of data derived primarily from urban settings that are not generalizable to national populations; the inability to derive the true number of deaths attributable to RSV from the hCFR; and difficulties in comparing current meta-analysis data with other meta-analyses due to differences in case definitions, means of RSV detection, time periods, and more.
“In conclusion, there is a significant burden of disease of RSV among ≥60-year-old adults in high-income countries, and estimates point towards higher rates than previously reported.” They anticipate increased pressure from RSV infections on health care systems with aging population and the possibility of comorbid influenza and SARS-CoV-2.
Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Savic M, Penders Y, Shi T, Branche A, Pirçon JY. Respiratory syncytial virus disease burden in adults aged 60 years and older in high-income countries: A systematic literature review and meta-analysis. Influenza Other Respir Viruses. Published online November 11, 2022. doi:10.1111/irv.13031