Tis the Season for Norovirus Out West

As public health officials in California warn of a jump in reported cases of norovirus—also known as winter vomiting disease—across the state, a preholiday gathering in Seattle illustrates the speed with which the virus can wreak havoc in tightly packed events. The California Department of Public Health has confirmed 32 outbreaks that sickened hundreds between October and the end of 2015. Meanwhile, more than 200 people came down with symptoms of norovirus, which include abdominal pain, vomiting and diarrhea, after attending a single event in a Seattle office building. Given its sudden onset—typically, 12-48 hours after exposure—and unpleasant symptoms, urgent care centers are a likely destination for its victims. While not usually dangerous to otherwise healthy adults, norovirus strikes some 20 million people annually, resulting in as many as 800 deaths.  New strains are known to emerge periodically, but it is not clear yet whether the current surge represents an existing or newly evolved strain.