Although it is emerging as a significant cause of foodborne disease around the world, the true cost of a norovirus outbreak is rarely appreciated. Bartsch et al. (2016) conducted a global assessment, using a computational simulation model to estimate the economic burden of norovirus disease in countries around the world1. They analyzed the results by country, stratifying data according to various other factors including national income data. From this the researchers found that although health costs are higher in high income countries and productivity losses are similar globally, the disease has more impact in terms of affecting household income in low-to-middle income (LMIC) nations, which thus bear a greater cumulative norovirus disease burden.
Norovirus is perhaps the perfect foodborne pathogen. Outbreaks occur as a result of eating contaminated foods as well as exposure to vomitus and feces from infected individuals. Only 20 virus particles are required to establish infection so it is imperative for food producers to ensure hygiene at all stages during product preparation, packaging and final handling before delivery to the consumer. Immunity is short-lived in most individuals due to viral mutation, so previous disease does not establish resistance beyond a few months.
Drawing from various data inputs including the United Nations, the World Health Organization and its Foodborne Disease Burden Epidemiology Reference Group (FERG) report on global burden in 2010, Bartsch et al. found that norovirus causes 699 million illnesses per year, resulting in approximately 219,000 deaths. The majority of deaths occur in older adults (>55 years) but 70,000 children under the age of five years die each year due to norovirus. This latter age group also shoulders the greatest societal burden generated by the disease, especially in LMIC nations.
Compared with other causes of acute gastroenteritis, such as rotavirus, norovirus receives much less attention globally for research into prevention, eradication and treatment. Bartsch et al. note that lack of attention to the disease could come from various factors;
- Testing methods for patients are not widely available, especially in developing countries, meaning that the disease may be under reported.
- The disease is strongly associated with cruise ship passengers, as a disease of leisure and hence underestimated as not important.
- It is self-limiting and rarely causes death.
However, compared with rotavirus, the total burden from norovirus is far greater.
According to the data collected by Bartsch et al. the cumulative cost of norovirus globally stacks up at $60.3 billion dollars as a societal (productivity loss, premature death, absence from work) financial burden (rotavirus, $423 million), with $4.2 billion for healthcare per annum (rotavirus, $325 million). In general, older adults contribute more to the healthcare burden, especially in high-income nations due to hospitalization costs. Disease in children amounts to $39.8 billion of the global societal costs, compared with $20.4 billion for all the other age groups. Running a computer simulation predicting 25% probability of absence from work, loss in productivity, expressed as a percentage of burden, averaged around 93% globally. This percentage was relatively consistent among all nations and generated $56.2 billion in economic loss. The researchers found that most of this loss came from premature death.
As Bartsch and colleagues state, there is indeed an “economic argument for greater consideration of norovirus” as a public health priority. So how can the food industry help?
In addition to public health initiatives aimed at promoting good food hygiene among populations, there are steps that the food industry can take in combating the rise of norovirus as a foodborne disease. Being aware of viral biology is a first step and producers can use this knowledge to establish effective production practices to control and minimize contamination with foodborne pathogens. Being alert to the role that food plays in transmitting disease is an excellent first step in reducing the burden of norovirus in all countries.
1. Bartsch, S.M. et al. (2016) “Global Economic Burden of Norovirus Gastroenteritis“, PLoS ONE 11(4): e0151219. doi:10.1371/journal.pone.0151219