It is nasty, and the norovirus that is causing widespread outbreaks of diarrhea and vomiting across North Carolina is one super bug.

Impervious to sanitizing gels, able to sicken wide groups of people in tiny amounts and fearing no vaccine, the norovirus has struck conferences, play groups, schools, restaurants, retirement homes and day care centers.

"It's a very successful virus," said David Bergmire-Sweat, food-borne disease epidemiologist for the state Division of Public Health.

A count of infections isn't available, Bergmire-Sweat said, because the ailment isn't among those the state tracks and reports to the Centers for Disease Control and Prevention. But he said outbreaks can sweep through large clusters of people in waves of illness, with just a few particles of the virus transmitted in airborne droplets, on surfaces or in contaminated food.

And it packs a wallop. Although the intestinal turmoil usually lasts no more than a couple of days, it can be serious for older adults, young children and people with fragile immune systems. AtWakeMed in Raleigh, hospital officials said Wednesday that they've seen a large number of people in the emergency department in the grip of the virus's misery.

Most are sent home. There is no treatment.

Agnes Stevens, with the state's Alcoholic Beverage Control Commission, went from feeling fine to feeling wretched within two hours Sunday evening, and spent the entire night vomiting.

"It was not an experience I enjoyed," she said. Wiped out, she took Monday off.

The virus can spread from its recent victims days and weeks after they've fully recovered.

State health officials caution people who have had bouts of the virus to refrain from fixing food for at least 48 hours, and to wash clothing and bedding in detergent and hot water.

What's also little known is that norovirus is untouched by sanitary hand gels, which rely on alcohol to kill germs. Only bleach works against noroviruses, so people are better off washing their hands in warm, soapy water.

Other than that, science offers little against the pathogen. Along with no treatment, there's no vaccine.

Seeking a vaccine

Ralph Baric, an epidemiologist at the Gillings School of Global Public Health at UNC-Chapel Hill, is working to rectify that. Baric, who studies noroviruses, said he has had success immunizing mice against the virus. His technique uses inactivated parts of the pathogen to train the immune system into mounting a defense.

But the virus is tricky. Like influenza, it comes in dozens of strains, and it's constantly changing. As a result, people have almost no immunity to any one variant. Baric said people can suffer norovirus illness time and again, because each bout can be caused by a different strain.

For his vaccine to work, he said, he'll have to pack the inoculation with multiple strains, selecting them through a process similar to how seasonal flu shots are created each year.

But there is a good potential market among older people, the military and travelers. Cruise ship companies also have strong interest.

"Between 10 million and 20 million people take cruises each year," Baric said. "Cruise ship companies spend a tremendous amount of money and time and effort keeping the viruses off ships."

And still the virus cannot be vanquished. Half the time, Baric said, it's the culprit behind traveler's revenge.

savery@newsobserver.com or 919-829-4882