Respiratory Syncytial Virus Infection in Older Adults in Asia: A Modified Delphi Expert Consensus on Surveillance, Diagnosis, and Prevention

Abstract

Introduction: Respiratory syncytial virus (RSV) is a public health concern, particularly among neonates/young infants, in individuals with chronic medical conditions, and for older adults. In contrast to children, limits in surveillance and substantial underreporting obscure the full impact of RSV infections on adults. A structured process for adult RSV disease decision-making can guide public health epidemiology and planning. Methods: Twelve experts from six Asian countries (Indonesia, Malaysia, Philippines, Singapore, Taiwan, and Thailand) participated in a modified Delphi consensus study to guide surveillance, diagnosis, and impact of RSV in adults in Asia. The expert recommendations could be organized into four themes: epidemiology and surveillance, diagnosis, high-risk groups, and healthcare utilization. Results: The expert panel recommended strengthening RSV disease monitoring through integration within current influenza and COVID-19 surveillance systems. Furthermore, to standardize RSV case definitions, it was recommended that the RSV respiratory infection clinical criteria exclude fever. Although rapid antigen tests are employed as standard of care, polymerase chain reaction (PCR) testing should be utilized whenever feasible. Along with year-round testing in Asia to establish incidence, an adjustment factor of at least 2.2-fold was recommended to address the underestimation of RSV-related hospitalization rates based on single-specimen PCR testing. For all adults aged ≥ 75 as well as for those adults aged ≥ 60 with comorbid or immunocompromising conditions, or those residing in long-term care facilities, the experts recommended universal RSV vaccination (contingent upon vaccine licensure), and cost-effectiveness analyses should be used to inform region-specific policy decisions. Conclusions: Priority actions proposed for adult RSV infection and disease include streamlining diagnostic testing processes, launching disease awareness campaigns, and engaging public health authorities to advance prevention programs in coordinated efforts with policymakers and payers.