The estimated disease burden of norovirus in The Netherlands

Noroviruses are an important cause of acute gastroenteritis in humans. We incorporated new insights gained over the past decade in an updated estimate of the disease burden of (foodborne) norovirus illness in The Netherlands in 2009. The disease outcomes - non-consulting cases, visiting a general practitioner, hospitalization and mortality - and the foodborne proportion were derived from cohort studies, surveillance data and literature. Age-specific incidence estimates were applied to the population age distribution in The Netherlands in 2009. The general population incidence was 3800/100 000 (95% CI 2670-5460), including 0.4 fatal cases/100 000, resulting in 1622/100 000 (95% CI 966-2650) disability-adjusted life-years in a population of 16.5 million. The updated burden of norovirus is over twofold higher than previously estimated, due in particular to the new insights in case-fatality ratios. Results suggest that the burden of norovirus institutional outbreaks is relatively small compared to the burden of community-acquired norovirus infections.