Respiratory Syncytial Virus Infections in Recipients of Bone Marrow Transplants: A Systematic Review and Meta-Analysis

Abstract

Human Respiratory Syncytial Virus (RSV) is a common cause of respiratory tract infections. Usually associated with infants and children, an increasing amount of evidence suggests that RSV can cause substantial morbidity and mortality in immunocompromised individuals, including recipients of bone marrow transplantation (BMT). The present systematic review was therefore designed in accordance with the PRISMA guidelines to collect available evidence about RSV infections in BMT recipients. Three medical databases (PubMed, Embase, and MedRxiv) were therefore searched for eligible observational studies published up to 30 September 2023 and collected cases were pooled in a random-effects model. Heterogeneity was assessed using I2 statistics. Reporting bias was assessed by means of funnel plots and regression analysis. Overall, 30 studies were retrieved, including 20,067 BMT cases and 821 RSV infection episodes. Of them, 351 were lower respiratory tract infections, and a total of 78 RSV-related deaths were collected. A pooled attack rate of 5.40% (95% confidence interval [95%CI] 3.81 to 7.60) was identified, with a corresponding incidence rate of 14.77 cases per 1000 person-years (95%CI 9.43 to 20.11), and a case fatality ratio (CFR) of 7.28% (95%CI 4.94 to 10.60). Attack rates were higher in adults (8.49%, 95%CI 5.16 to 13.67) than in children (4.79%, 95%CI 3.05 to 7.45), with similar CFR (5.99%, 95%CI 2.31 to 14.63 vs. 5.85%, 95%CI 3.35 to 10.02). By assuming RSV attack rates as a reference group, influenza (RR 0.518; 95%CI 0.446 to 0.601), adenovirus (RR 0.679, 95%CI 0.553 to 0.830), and human metapneumovirus (RR 0.536, 95%CI 0.438 to 0.655) were associated with a substantially reduced risk for developing corresponding respiratory infection. Despite the heterogeneous settings and the uneven proportion of adult and pediatric cases, our study has identified high attack rates and a substantial CFR of RSV in recipients of BMT, stressing the importance of specifically tailored preventive strategies and the need for effective treatment options.

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”.…”

Impact of Nirsevimab Immunization on Pediatric Hospitalization Rates: A Systematic Review and Meta-Analysis (2024)

“…A highly contagious and diffusive pathogen [ 18 , 25 ], at the global level, RSV causes approximately 33 million cases of ARIs and LRTIs in infants aged 5 years old or less every year [ 4 , 5 , 26 ], with high hospitalization rates [ 27 , 28 , 29 , 30 , 31 ] leading to around 3.5 million hospital admissions [ 3 , 5 ]. Even though RSV can result in a high case fatality ratio in children affected by pre-existing comorbidities [ 4 , 5 , 19 , 21 , 26 , 32 , 33 ], most of the cases occur in otherwise healthy infants [ 4 , 34 ] and are usually clustered in seasonal epidemics (i.e., “RSV season”) associated with seasonal climate that forces individuals in enclosed spaces, increasing the likelihood for the inter-human spreading of the pathogen [ 35 , 36 , 37 , 38 ]. Therefore, the RSV season in the Northern Hemisphere has historically been associated with the winter season, peaking between December and January [ 4 , 26 ], extensively overlapping with other respiratory viruses such as influenza and adenovirus [ 39 , 40 ] and, more recently, with SARS-CoV-2 [ 41 , 42 ], as well as with the hot, humid, and rainy climates of the summer season in tropical countries [ 36 , 37 , 43 , 44 ].…”