The Vast and Varied Global Burden of Norovirus: Prospects for Prevention and Control

Abstract

Globally, norovirus is associated with approximately one-fifth of all diarrhea cases, with similar prevalence in both children and adults, and is estimated to cause over 200,000 deaths annually in developing countries. Norovirus is an important pathogen in a number of high-priority domains: it is the most common cause of diarrheal episodes globally, the principal cause of foodborne disease outbreaks in the United States, a key health care–acquired infection, a common cause of travel-associated diarrhea, and a bane for deployed military troops. Partly as a result of this ubiquity and burden across a range of different populations, identifying target groups and strategies for intervention has been challenging. And, on top of the breadth of this public health problem, there remain important gaps in scientific knowledge regarding norovirus, especially with respect to disease in low-income settings.Many pathogens can cause acute gastroenteritis. Historically, rotavirus was the most common cause of severe disease in young children globally. Now, vaccines are available for rotavirus and are universally recommended by the World Health Organization. In countries with effective rotavirus vaccination programs, disease due to that pathogen has decreased markedly, but norovirus persists and is now the most common cause of pediatric gastroenteritis requiring medical attention. However, the data supporting the precise role of norovirus in low- and middle-income settings are sparse. With vaccines in the pipeline, addressing these and other important knowledge gaps is increasingly pressing.We assembled an expert group to assess the evidence for the global burden of norovirus and to consider the prospects for norovirus vaccine development. The group assessed the evidence in the areas of burden of disease, epidemiology, diagnostics, disease attribution, acquired immunity, and innate susceptibility, and the group considered how to bring norovirus vaccines from their current state of development to a viable product that will benefit global health.

Report from the World Health Organization’s third Product Development for Vaccines Advisory Committee (PDVAC) meeting, Geneva, 8–10th June 2016

“…In April 2016, PLOS released a collection on 'The Global Burden of Norovirus & Prospects for Vaccine Development' [21], which includes the most current estimates on global norovirus disease burden of over 200,000 deaths in low resource countries, and a global economic burden of more than $60 billion [22]. Recent molecular analyses of samples from the community based longitudinal birth cohort MAL-ED study suggest that norovirus is the most common diarrheal pathogen in the first year of life, and the second most common in the second year of life.…”

Norovirus Disease in Older Adults Living in Long-Term Care Facilities: Strategies for Management

“…Clinical trials have demonstrated safety, immunogenicity, and efficacy of some products [56, 57], although the development of norovirus vaccines is challenging due to the high degree of virus genetic diversity, rapidly evolving new variant strains, and an incomplete understanding of immune correlates of protection [41••, 58••]. The future efficacy of norovirus vaccines may rely on the development of products eliciting a broad cross-protective immune response against heterologous virus [41••].…”

Three-Dimensional Rotating Wall Vessel-Derived Cell Culture Models for Studying Virus-Host Interactions

“…Over 200,000 children under the age of five die every year from human norovirus (HuNoV) infections, with norovirus infection representing the second leading cause of diarrheal death in this age group [67,68,69]. An effective cell culture model for modeling HuNoV infections and interactions with intestinal epithelial cells has been elusive, slowing the development of urgently-needed interventions for this deadly illness [70].…”