Noroviruses leading cause of diarrhoea and vomiting: Lancet

New estimates have suggested that noroviruses cause around a fifth of all cases of acute gastroenteritis (diarrhoea and vomiting) across all age groups.

Noroviruses are responsible for almost a fifth (18 per cent) of all cases worldwide.

According to the authors, new estimates highlight the importance of developing norovirus vaccines.

Lead author Dr Benjamin Lopman from the Centers for Disease Control and Prevention in the USA, said including data from 48 countries and involving more than 187 000 gastroenteritis cases worldwide, these new estimates are the largest analysis of norovirus infection and disease to date. There has been a proliferation of research on norovirus globally in the last five years, and we harnessed that data for this study.

Lopman and colleagues analysed 175 published reports to compile data on the prevalence of norovirus in individuals with acute gastroenteritis between 1990 and 2014.

They found that norovirus tended to be more common in cases of acute gastroenteritis in the community (24 per cent) and outpatient (20 per cent) settings than in emergency department visits and hospitalisations (17 per cent), supporting the notion that norovirus is a more common cause of mild disease. However, because of its sheer frequency, norovirus causes a substantial amount of severe disease.

Norovirus was also found in a considerable proportion of cases of acute gastroenteritis cases in both developing countries (14-19 per cent) and developed countries (20 per cent). "This highlights that norovirus, unlike bacterial and parasitic pathogens, cannot be controlled just by improved water and sanitation"*, explains Lopman.

The new estimates have been published in The Lancet Infectious Diseases.