A new strain of norovirus is causing intestinal illness outbreaks across the country, the CDC confirmed today.
Norovirus is often to blame when large numbers of people get sick on cruise ships or in schools, nursing homes, and other places where people live, work, or play in close quarters.
CDC officials also reported a rise in outbreaks of sickness caused by drinking raw milk.
The findings appear in the Jan. 25 issue of the Morbidity and Mortality Weekly Report.
New Norovirus Spread Quickly
The new norovirus strain was first identified in Australia in March of last year, and it had spread across the United States by year’s end.
Of the 266 norovirus outbreaks reported during the last four months of 2012, 141 involved the Australian strain. During this time, outbreaks caused by it rose from 19% to 58%.
Sickness from norovirus is often called "food poisoning," but the highly contagious virus can also be spread by water, person-to-person contact, or simply by touching an infected object.
Outbreaks can happen anytime, but they are most common in the winter months.
Cruise Ship Outbreak Involved New Strain
A norovirus outbreak late last week that involved 300 children at an Arkansas middle school was not caused by the newer strain. But one that happened during a Christmas sailing of the luxury cruise ship Queen Mary 2 was, says Jan Vinje, PhD, who heads the National Calicivirus Laboratory at the CDC.
CDC epidemiologist Aron Hall says it may not be clear for several months if more people are getting sick or more outbreaks are occurring as a result of the new strain.
“We see new strains emerge every few years and sometimes they are associated with increased disease activity,” he says. “We certainly want people to be aware that this potential exists, but the mainstays of norovirus prevention are still the most important things people can do to protect themselves.”
He suggests these strategies to prevent infection:
- Wash your hands often.
- Disinfect surfaces.
- Avoid preparing food or caring for others when you're sick.
- Keep your hands away from your face as much as possible.