Epidemiology and burden of respiratory syncytial virus in Italian adults: A systematic review and meta-analysis

Abstract

Objective Respiratory syncytial virus (RSV) is a common respiratory pathogen not only in children, but also in adults. In view of a recent authorization of adult RSV vaccines in Italy, our research question was to quantify the epidemiology and burden of RSV in Italian adults. Methods Observational studies on the epidemiology and clinical burden of laboratory-confirmed or record-coded RSV infection in Italian adults of any age were eligible. Studies with no separate data for Italian adults, modeling and other secondary publications were excluded. A literature search was performed in MEDLINE, Biological Abstracts, Global Health, Scopus and Web of Science on 22 November 2023. Critical appraisal was performed by means of a Joanna Briggs Institute checklist. Random-effects (RE) meta-analysis was performed to obtain pooled estimates and the observed heterogeneity was investigated by subgroup and meta-regression analyses. The protocol was prospectively registered (doi.org/10.17504/protocols.io.5qpvo32odv4o/v1). Results Thirty-five studies were identified, most of which had at least one possible quality concern. RSV seasonal attack rates ranged from 0.8 ‰ in community-dwelling older adults to 10.9% in hematological outpatients. In the RE model, 4.5% (95% CI: 3.2–5.9%) of respiratory samples tested positive for RSV. This positivity prevalence was higher in older adults (4.4%) than in working-age adults (3.5%) and in outpatient (4.9%) than inpatient (2.9%) settings. According to the meta-regression, study location and sample size were also significant predictors of RSV detection frequency. The pooled estimate of in-hospital mortality was as high as 7.2% (95% CI: 4.7–10.3%). Data on other indicators of the diseases burden, such as complication and hospitalization rates, were unavailable. Conclusion RSV poses a measurable burden on Italian adults, especially those of older age and with some co-morbidities. However, several data on the natural history of RSV disease are missing and should be established by future large-scale studies.

Occurrence of Central Nervous System Complications of Respiratory Syncytial Virus Infections: A Systematic Review with Meta-Analysis

“…In this regard, it should be stressed that a large number of RSV cases are usually not properly diagnosed, even severe ones otherwise requiring hospitalization [ 5 , 6 ]. RSV is mostly considered a pediatric-age pathogen [ 171 , 172 ], and adults are therefore not consistently sampled for this pathogen, even when belonging to high-risk groups [ 173 , 174 ], with resulting underestimation of its actual occurrence. A potential strategy for reconciling with the misdiagnosis of RSV infections may be to include this pathogen in all clinical and laboratory workflows performed on cases of suspected viral encephalitis and encephalopathies of uncertain cause, particularly during the “RSV season”.…”

From Forgotten Pathogen to Target for New Vaccines: What Clinicians Need to Know about Respiratory Syncytial Virus Infection in Older Adults

“…Falsey et al were among the first to take an interest in the topic with some of their works on factors associated with disease severity and mortality remaining the most common references in the field [ 2 , 3 ]. In the last four years, several systematic reviews and meta-analyses were published [ 15 , 16 , 17 , 25 , 27 , 29 , 31 , 32 , 41 ], most of them with the aim to define the disease burden of RSV in older adults and some of them with the active participation of pharma companies involved in RSV vaccine and drug development. Several clinical studies have been published over the years worldwide [ 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ].…”

“…Almost all the works that attempted to estimate the RSV disease burden in older adults reported several limitations. These are basically due to the processing data from studies performed with very different methods and protocols [ 107 ]; being based on the case definition of influenza-like illness [ 108 ]; lacking the necessary data to stratify by age group; being based on data mainly derived from academic, high-income, in-hospital settings [ 31 , 67 ]; and underestimating the presence of other factors, such as coinfections or complications [ 15 ]. To address these limitations, the WHO published a document with the essential guidelines to be followed in estimating the RSV disease burden [ 109 ], but robust evidence is lacking.…”

“…Respiratory syncytial virus (RSV) is a well-recognized cause of acute respiratory tract illness among infants, with the first case of RSV-related bronchiolitis described as early as 1957 [ 1 ]. However, RSV is also increasingly recognized as being implicated in acute illness in older adults [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], contributing to a considerable burden in hospitalizations for respiratory illness while presenting mortality rates that are close to those associated with illness caused by influenza viruses [ 16 , 17 , 18 ].…”