Abstract
INTRODUCTION: There is a gap in the understanding of the burden of respiratory syncytial virus (RSV) among adults in low, lower-middle, and upper-middle income countries, particularly with regard to up-to-date epidemiological data. Meta-analyses were conducted to determine pooled estimates of RSV prevalence among high-risk 18-59-year-old adults and ≥ 50-year-old adults with or without risk factors or comorbidities, who present with respiratory illnesses in low, lower-middle, and upper-middle income countries. METHODS: Using studies identified from a previously described systematic literature review, a random-effects model was used to determine pooled prevalence for each study population. Subgroup analyses and meta-regression were conducted using the moderator variables deemed most relevant a priori and a mixed-effects approach. RESULTS: Pooled RSV prevalence estimates were 5.1% (95% confidence interval [CI] 3.9-6.6%) and 3.9% (95% CI 3.3-4.7%) across 33 studies in 18-59-year-old high-risk adults with respiratory illnesses and 66 studies in ≥ 50-year-old adults with respiratory illnesses, respectively. Subgroup analyses for 18-59-year-old high-risk adults found geography, study setting, and respiratory illness to collectively explain ~ 54% of the variation in RSV prevalence estimates. The diagnostic method for RSV was found to explain ~ 8% of the variation in RSV prevalence estimates in ≥ 50-year-old adults; no other factors explored via subgroup analyses for ≥ 50-year-old adults had a notable effect on variation. For both populations, a substantial level of residual heterogeneity was observed using Higgin's I(2) when studies were split for subgroup analyses. CONCLUSIONS: Overall, there is a considerable disease burden associated with RSV among 18-59-year-old high-risk and ≥ 50-year-old adults with respiratory illnesses in low, lower-middle, and upper-middle income countries, highlighting the need for improved prevention programs for RSV in these populations.