We may worry about salmonella in our chicken and the chemical additives in our bread.

But how often do we fret about the most common cause of food poisoning and serious stomach flu in the US?

No, we don't really talk much about norovirus, an extremely contagious bug spread by — prepare yourself — ingesting the stool or vomit of an infected person often through food or touching a contaminated surface.

That needs to change, according to researchers from Johns Hopkins Bloomberg School of Public Health and the Centers for Disease Control and Prevention.

Writing in PLoS One this week, they estimated the economic and social burden of the the virus, and found that it sickens 699 million people each year, kills 219,000, and costs society more than $60 billion annually worldwide — mostly in lost productivity.

You can see the global toll of norovirus here:

The article, part of a collection from the journal on norovirus, makes a compelling argument for why the world needs to wake up to the threat.

Since there are so many strains of the virus, people don't typically develop lifelong immunity once they've been infected, leaving them vulnerable to multiple bouts of severe diarrhea or vomiting in their lifetime.

Even though people typically recover after a few days of intense discomfort, the researchers point out, norovirus can be serious and even deadly, particularly for young children and the elderly. And beyond the human toll, the virus can be costly for society in developed and developing countries alike:

"low, middle and high income countries all have a considerable economic burden, suggesting that norovirus gastroenteritis is a truly global economic problem."

Ben Lopman, lead author on the article, explained in a related blog post that, in addition to inattention, researchers are up against steep scientific obstacles in controlling norovirus:

"Chief among these is the inability to efficiently grow norovirus in cell culture. Without a cell culture system, it’s been difficult to develop diagnostics, infectivity assays and vaccines."

Until advances are made in better understanding the virus, a vaccine will remain elusive. But first, the authors urged, we need to get more serious about the threat of norovirus and invest more in solutions.