"It's here. A variant of norovirus first spotted in Australia is now sweeping the U.S."

"The wily virus causes stomach upset, vomiting and diarrhea. The sickness is sometimes referred to as the stomach flu, though influenza has nothing to do with it."

"Since the strain called 'GII.4 Sydney' was identified in Australia last March, it's been getting around. The U.K. has had a bang-up norovirus season with more than a million people sickened. The new strain has also struck in France and New Zealand."