Scientists Close in on the Notorious Cruise Ship Virus

Over the past few weeks, a Princess Cruises vessel was hit by an outbreak of norovirus, the common stomach bug notorious for wreaking havoc on cruise liners. Over 170 people on board the month-long trip were affected, with most reports coming in the last 15 days. The ship docked on Sunday in Los Angeles, where the vessel received a lengthy decontamination before its next voyage. Though the disease is generally thought of as a mild infection that primarily affects seaborne vacationers, norovirus-prompted food poisoning generates around $2 billion in annual healthcare and lost productivity costs in the United States alone.

Norovirus causes vomiting and diarrhea, and is typically spread through coming into contact with contaminated surfaces or objects, such as doorknobs, handrails and utensils—hence its tendency to thrive on ships, in schools, and in hotels. Most cruise companies put stringent measures into effect to prevent outbreaks, like installing automatic hand sanitizing units in the ship’s common areas. However, the virus is resistant to many common disinfectants.

Transmission electron micrograph of norovirus particles in feces. By Graham Colm via Wikimedia Commons

According to the Centers for Disease Control and Prevention, norovirus causes up to 21 million cases of illness per year in the U.S., contributing to between 570 to 800 deaths, mainly young children and older adults. While scientists are working on a vaccine, no current medication exists to treat norovirus—partly because no one has been able to study the illness at close range.

Earlier this year, though, researchers at University of Florida’s College of Medicine moved a step closer toward a solution, successfully growing a human norovirus cell in the lab for the first time. The results of the study, published in a recent issue of Science, show that the virus weakens the immune system by targeting white blood cells in the intestine, not, as previously thought, by attacking the protective cells that line the intestinal wall.

Stephanie Karst, a professor in the University of Florida department of molecular genetics and microbiology, said the biggest hurdle in norovirus research had been scientists’ continued failure to grow the human virus in a laboratory cell culture dish. “That complicates every aspect of research,” Karst said in a news release about the discovery. “We can’t study how it replicates, and we can’t test therapeutics.”

The new discovery could lead to new drugs to combat norovirus, potentially saving a high cost in both lives and resources and maybe a few cruise vacations in the process.