The alley-oops, 1440s, and triple axels weren’t the only aerial feats in evidence at the PyeongChang Olympics.
While the athletes were defying gravity on skis, snowboards and skates, a ruthless pathogen — the norovirus — was stealthily demonstrating its own airborne prowess.
Norovirus sent hundreds of Olympic staff and volunteers home with diarrhea, vomiting, fevers, severe aches, and headaches. More than 1000 security workers were quarantined while being tested for the virus.
Whenever there’s a high-profile norovirus outbreak, news reports focus on the potency of the bug, and for good reason: norovirus — spread through fecal matter and vomit — is so contagious that as few as 10 viral particles can trigger illness. But what reports rarely mention: norovirus isn’t just spread via surfaces and in food and water. You can fall ill just by breathing contaminated air.
Norovirus particles are the Olympians of the virus world — powerful and fast, with incredible endurance. The virus can withstand both freezing and scorching temperatures. Hand sanitizers and common disinfectants are no match for it, either. And the virus is persistent; infected people can remain contagious for up to two weeks after recovering. No wonder custodians cleaning up after outbreaks wear hazmat suits.
Unlike Olympic skiers and skaters, who eventually come down for a landing, norovirus particles are so small and light they can remain afloat indefinitely. If an infected person vomits, and you simply walk by, you can get sick yourself.
A single vomiting episode can release more than 13,000 particles of norovirus into the air, according to published research using a device that replicates human vomiting. (The gizmo features an “esophagus” designed to project faux vomit into a clear, sealed box. A sensor detects the number of virus particles floating around.)
“When one person vomits, the aerosolized virus particles can get into another person's mouth and, if swallowed, can lead to infection,” says microbiologist Lee-Ann Jaykus, Ph.D., a professor at North Carolina State University and co-author of the simulated vomiting study.
What’s more, those airborne particles can land on nearby surfaces, such as tables, toilet handles, and door knobs. “Norovirus can hang around for weeks, so anyone that touches that table and then puts their hand to their mouth could be at risk for infection,” Jaykus says.
Norovirus, the world’s most common cause of diarrhea, makes headlines when it wreaks havoc at high-profile events, like the Olympics or the Republican National Convention, or when hundreds are felled on cruise ships or college dormitories.
But the virus does most of its damage out of the spotlight, contaminating the air and sickening the populations at hospitals, long-term care facilities, senior centers, and schools.
Norovirus particles are lurking all over indoor facilities. A Canadian research team, from the Université Laval's Faculty of Science and Engineering, studied eight hospitals and long-term care facilities that had been struck by gastroenteritis outbreaks and found norovirus particles in the air at six of the facilities. The researchers detected the virus in 54% of the rooms housing patients with gastroenteritis and 38% of the hallways leading to their rooms and at 50% of nursing stations.
Because norovirus is so ubiquitous and so contagious — and because it mutates rapidly, allowing individuals to be re-infected — the “winter vomiting virus” takes a huge toll. The virus strikes nearly 700 million people annually and kills 200,000, most of them children or elderly, who succumb to virus-induced dehydration or malnutrition. The financial toll approaches $60 billion, in direct and indirect costs.
But the virus, wily and hardy as it has proven to be, can be stopped.
The key is to clean both surfaces and the air.
Historically, prevention and clean-up have focused on surfaces. When an outbreak occurs, folks are urged to and wash their hands thoroughly and frequently with soap and warm water, especially before handling food or after using the toilet, and to use highly concentrated chlorine bleach solutions. (The U.S. Environmental Protection Agency lists cleaning products known to slay norovirus.)
But cleaning surfaces is only half the battle against this Olympic-level pathogen; purifying the air is also critically important for stopping its spread.
Norovirus — relentlessly contagious and always on the move — can’t be eradicated, but outbreaks, big and small, can be prevented with the right kind of air purification technology.
Hopefully when the next Olympic Games come around, the news will focus on airborne athletes, not vomit-inducing norovirus particles.