Norovirus sickens almost 700 million people a year

"It doesn't matter how old you are or if you're in a wealthy country or a poorer one or if you've had it before—you can get it again," says Sarah M. Bartsch. "And it is really unpleasant. But if we don't focus on norovirus and teach people how to prevent it, little headway will be made to combat it." (Credit: iStockphoto)

The news often mentions norovirus when it’s relatively contained to a cruise ship or college campus, but it actually sickens nearly 700 million people a year.

The illness causes roughly $4.2 billion in health care costs and $60.3 billion in societal costs, new research concludes.

“It has been flying under the radar for too long.”

The findings, published online in the journal PLOS ONE, are believed to be the first to look at the global economic burden of norovirus, which is common in both wealthy and poor nations. The study suggests that much more attention is needed to combat a disease that kills approximately 219,000 a year around the world, the researchers say.

“You only seem to hear about it when people get sick on a cruise ship or at a restaurant, but norovirus is everywhere,” says study leader Sarah M. Bartsch, a research associate at the Johns Hopkins University Bloomberg School of Public Health.

“It doesn’t matter how old you are or if you’re in a wealthy country or a poorer one or if you’ve had it before—you can get it again,” Bartsch says. “And it is really unpleasant. But if we don’t focus on norovirus and teach people how to prevent it, little headway will be made to combat it.”

‘Flying under the radar’

The study’s senior author, Bruce Y. Lee, associate professor of international health at the Bloomberg School, says that the costs associated with norovirus are higher than for many diseases that get more attention. For instance, the burden of rotavirus, a diarrheal disease that kills many babies but rarely endangers anyone over age 5, was estimated at $2 billion a year before a vaccine was rolled out.

“Our study presents an economic argument for greater consideration of norovirus,” Lee says. “It has been flying under the radar for too long.”

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Norovirus is easily transmissible and can cause severe gastrointestinal symptoms, including nausea, diarrhea, and vomiting. Fewer than 1 percent of cases are associated with outbreaks, although those get the most public notice. There is no vaccine or treatment. Researchers say norovirus is not routinely tested for and the number of cases may be an underestimate.

In 2015, there were norovirus outbreaks reported on 23 cruise ships with US ports of call, affecting more than 2,500 passengers and crew, according to the US Centers for Disease Control and Prevention. In 2016, news reports have cited outbreaks at colleges and universities in Ohio, Michigan, Pennsylvania, California, and New York state. Restaurants are another frequently reported arena for transmission of the disease.

The whole burden

Bartsch and colleagues developed a computer model to estimate both medical costs and other economic costs of norovirus. Most notable among the latter is the cost of missed work, underperformance while sick, and premature death. The model estimated the cost for 233 countries, regions, and territories for which the United Nations has population data.

[These scientists were first to grow norovirus in a dish]

“Lost productivity is a big part of the cost,” Lee says. “By just focusing on health care costs, or simple measures such as death caused by the disease, we miss a lot of the burden. Productivity losses tend to go unrecognized, but make up 94 percent of the global economic burden of norovirus.”

The researchers say they hope their work will help funding agencies and public health bodies decide where to best spend money for intervention and control, including for public education. Hand washing, proper food preparation, better food and water sources, and isolation of those who are sick are some methods for protecting against norovirus.

The Agency for Healthcare Research and Quality, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the Global Obesity Prevention Center at the Bloomberg School supported the work.

Source: Johns Hopkins University