Umeå universitets logga

Background: Respiratory syncytial virus (RSV) is a leading cause of acute respiratory infection and hospitalization in young children. Despite its significant burden, prophylaxis for all young children has only recently become available. Understanding the disease burden among this population is critical to evaluate the potential impact of new prophylactic options.

Methods: This case-cohort study used data from the Swedish national registers. However, 31, 907 hospitalized RSV cases aged <60 months and 95, 697 age-matched comparators were included from 2006 to 2022. The study investigated patient characteristics, incidence, short- and long-term healthcare resource use, associated costs, mortality and associations with high-risk conditions.

Results: Most cases (84.4%) were born at full-term and were otherwise healthy. RSV incidence ranged from 203.3 per 100, 000 (2006–007) to 708.4 per 100, 000 (2021–2022), with the highest rates in children aged 1–<2 months. RSV accounted for 27.0% of all hospitalized acute respiratory infection cases. In the 30 days following index, 61.8% of RSV cases had an outpatient care visit, compared to 12.0% of comparators, and short-term care costs for cases totaled €27 million in 2021-2022. In the 12 months following index, 87.6% of RSV cases had an outpatient care visit, while 47.1% of comparators did. Mortality among RSV cases was low (30-day Kaplan–Meier survival: 1.00, 95% CI: 1.00–1.00).

Conclusions: RSV hospitalization imposes a significant burden on young children in Sweden, most of whom are otherwise healthy. These findings support the adoption of prophylactic immunization strategies targeting all infants to mitigate this burden.