Background: Norway introduced routine rotavirus immunization for all children born on or after September 1, 2014. We estimated the healthcare burden of all-cause gastroenteritis and rotavirus disease in children <5 years old to establish the prevaccine baseline and support the ongoing immunization program.
Methods: We examined national registry data on gastroenteritis-associated primary care consultations and hospitalizations for 2009–2013 and data on all deaths in children <5 years old reported during 2000–2013. We also established rotavirus hospital surveillance from February 2014 through January 2015.
Results: Before vaccine introduction, 114.5 cases per 1000 children <5 years old were treated in primary care and 11.8 children per 1000 were hospitalized with gastroenteritis annually. During hospital surveillance, rotavirus was detected in 65% (95% confidence interval: 60–70) of inpatient gastroenteritis cases. We estimated that 4.0 inpatient and 2.3 outpatient cases per 1000 children were seen in hospital with rotavirus disease annually, suggesting that 1 in 32 children was hospitalized by age 5. Additional 30.6 rotavirus cases per 1000 children consulted primary care annually or 1 in every 7 children by the age of 5 years. Rotavirus-associated mortality was estimated at 0.17 deaths per 100,000 children <5 years old, corresponding to 1 death every second year.
Conclusions: Rotavirus remains the primary cause of severe gastroenteritis in children in Norway. The unique population-based registers, in combination with an established rotavirus surveillance platform, provide a well-suited setting to evaluate the impact of rotavirus vaccination.
From the *Department of Infectious Disease Epidemiology, †Department of Vaccines, ‡Department of Virology, Norwegian Institute of Public Health, Oslo, Norway; §Department of Pediatrics, ¶Department of Microbiology, Oslo University Hospital, Oslo, Norway; ‖Department of Pediatrics, **Department of Clinical Microbiology, Østfold Hospital Trust, Fredrikstad, Norway; ††Department of Pediatrics, St. Olavs University Hospital, Trondheim, Norway; ‡‡Norwegian University of Science and Technology, Trondheim, Norway; §§Department of Medical Microbiology, St. Olavs University Hospital, Trondheim, Norway; ¶¶Department of Pediatrics, and ‖‖Department of Medical Microbiology, Stavanger University Hospital, Stavanger, Norway.
Accepted for publication September 30, 2105.
The study was fully funded by the Norwegian Institute of Public Health. The authors have no conflicts of interest to disclose.
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Address for correspondence: Tone Bruun, MD, Department of Infectious Epidemiology, Norwegian Institute of Public Health, PO Box 4404, N-0403 Oslo, Norway. E-mail: firstname.lastname@example.org.