A Sydney, Australia, strain of norovirus is sweeping across the United States, in 140 outbreaks of a stomach bug known for it’s vomiting virus effects.
The virus strain isn’t dangerous, according to some scientists, but it is different and many people might not be able to fight off its symptoms.
The bug is having an impact as the new strain is making people sick in Japan, Western Europe, and other parts of the world. It was first identified last year in Australia and called the Sydney strain. In the U.S., it is now accounting for about 60 percent of norovirus outbreaks, according to the Centers for Disease Control and Prevention (CDC).
Norovirus — once known as Norwalk virus — is highly contagious and often spreads in places like schools, cruise ships and nursing homes, especially during the winter. Last month, 220 people on the Queen Mary II were stricken during a Caribbean cruise.
Sometimes mistakenly called stomach flu, the virus causes bouts of vomiting and diarrhea for a few days.
Every two or three years, a new strain evolves — the last was in 2009. The Sydney strain’s appearance has coincided with a spike in influenza, perhaps contributing to the perception that this is a particularly bad flu season in the U.S.
Ian Goodfellow, a prominent researcher at England’s University of Cambridge, calls norovirus ‘the Ferrari of viruses’ for the speed at which it passes through a large group of people.
“It can sweep through an environment very, very quickly. You can be feeling quite fine one minute and within several hours suffer continuous vomiting and diarrhea,” he said.
Health officials have grown better at detecting new strains and figuring out which one is the culprit. They now know that norovirus is also the most common cause of food poisoning in the U.S.
It’s spread by infected food handlers who don’t do a good job washing their hands after using the bathroom. But unlike salmonella and other food borne illnesses, norovirus can also spread in the air, through droplets that fly when a sick person vomits.
Each year, noroviruses cause an estimated 21 million illnesses and 800 deaths, the CDC says.