All-cause gastroenteritis hospitalisations of children decreased after the introduction of rotavirus vaccine in Stockholm

In Stockholm, Sweden, rotavirus vaccination was offered to children born after 1 March 2014. Our aim was to describe rates of hospitalisation due to community-acquired gastroenteritis before and after the introduction of the vaccine, and aetiology, underlying medical conditions and complications in admitted children.
We retrospectively included patients from our catchment area hospitalised with a diagnosis of gastroenteritis during ten infection seasons 2008/2009–2017/2018, whereof six seasons prevaccination and four seasons postvaccination. We studied virus detection data and the patients’ medical records.
We included 3718 episodes in 3513 children. In 2967 (80%), stools were tested with virus isolation, ELISA, PCR, or bacterial culture; 479 (16%) tested negative. The incidence rates, with 95% confidence intervals, for children <5 years hospitalised for rotavirus gastroenteritis were 2.9 (2.8–3.1) per 1000 person-years prevaccination and 0.65 (0.56–0.74) postvaccination, for a rate ratio (RR) of 0.22 (0.19–0.26, p < .001). The rates for all-cause gastroenteritis were 5.6 (5.4–5.9) prevaccination and 2.5 (2.3–2.7) postvaccination, RR 0.45 (0.42–0.50, p < .001). In 5–17-year-old children norovirus dominated with little change over time. Of patients <5 years, those with underlying conditions constituted a larger proportion postvaccination than prevaccination (30.7% vs. 24.2%, p < .001). A complication other than dehydration, most commonly seizures, arose in 8.8% of the patients <5 years prevaccination and 11.4% postvaccination (p < .05).
Rotavirus vaccination reduced the number of children <5 years requiring hospital care for gastroenteritis. We saw no replacement of rotavirus by other viruses.