Each year, norovirus infection is responsible for an estimated 684 million episodes of diarrhea and 212,000 deaths worldwide, and results in approximately $4.2 billion in healthcare costs and $60.3 billion in societal costs, a new report has highlighted.
Benjamin A. Lopman, PhD, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, and colleagues shared the results of their report
in PLOS Medicine
“Two-thirds of that burden is a result of disease in children under the age of five years. Low-, middle-, and high-income countries all have a considerable economic burden, indicating that norovirus gastroenteritis is a truly global economic problem,” the authors write.
Norovirus infection is the most common cause of gastroenteritis outbreaks worldwide, and the most common cause of foodborne disease in the United States. However, despite the increase in norovirus-related research in the last decade, as well as the availability of vaccines for norovirus that are recommended by the World Health Organization, progress in controlling the virus has remained slow. As a consequence, the CDC and the Bill and Melinda Gates Foundation assembled an expert group to examine the evidence for the global burden of norovirus and to consider how to address key gaps in the knowledge base about noroviruses—“with the ultimate goal of guiding the development of a norovirus vaccine for the populations that stand to benefit most: children in the developing world”.
In the article, the authors discuss data from some of the most recent norovirus studies. They stress that, so far, two main barriers have hindered norovirus control. One is the ubiquitous nature of norovirus gastroenteritis, and the second is because the virus is difficult to grow in cell culture in the laboratory—a key step in the development of diagnostic assays and vaccines against the virus. Indeed, the first demonstration of in vitro cell culture of norovirus was reported just 2 years ago, in 2014.
Dr. Lopman and colleagues emphasize some of the current data on the epidemiology and burden of norovirus disease in Africa, the United States, and military personnel—demonstrating just how common the virus is, even as it affects these diverse groups.
They note that, in African countries, norovirus is associated with 13.5% of diarrheal outbreaks in children. In addition, the incidence rate of norovirus disease in Kenya is approximately double that of the estimated rate in developed nations such as the United States, United Kingdom, and the Netherlands. Key information about norovirus in Africa is therefore lacking and is a critical knowledge gap.