A surge in norovirus cases might be explained by a new strain of the virus, which now reportedly makes up a majority of outbreaks across the U.S.
This winter’s dominant norovirus strain is a newer variant called the G11.17 [P17], CBS reports, citing data from a network of public health laboratories called CaliciNet that found seven in 10 outbreaks of the virus have tested positive for it.
It could explain why last month saw such a steep increase in cases of the highly contagious stomach bug that brings on sudden vomiting and diarrhea.
Jan Vinje, head of the Centers for Disease Control and Prevention’s CaliciNet system, told CBS that the strain is behind outbreaks “everywhere” across the U.S. this winter.
However, Vinje added it was “too early to tell” if the strain is associated with a more severe norovirus disease. Vinje told CBS: “Likely lower population immunity is the reason for the early surge of an otherwise seasonal increase of this virus.”
The G11.17 strain has been circulating for several decades, the network reports, and last year parts of Europe experienced a sudden rise.
Norovirus cases in the U.S. had previously been dominated by the G11.4 strain.
Experts also said that more studies were needed on the new variant. “What we are seeing has happened before for noroviruses. Noroviruses are very diverse,” Marion Koopmans, head of the Erasmus MC Department of Viroscience, told CBS.
It was previously reported that there were 91 outbreaks of the unpleasant stomach bug reported during the week of December 5, the most recent period data was available, which is up from 69 outbreaks in the last week of November.
The CDC said the figures exceeded previous years. “This year, the number of reported norovirus outbreaks have exceeded the numbers that we’ve seen recently and in the years before the pandemic,” the agency said.
While the majority of people will recover within a few days, every year norovirus causes 900 deaths, mostly among adults aged over 65 and older, according to CDC data.
The virus causes 465,000 emergency department visits, which are mostly young children.
Unfortunately, there is no quick fix or medication to treat norovirus so experts say rehydration and plenty of rest is key if you do catch it.
The good news is there are basic hygiene steps you can take to prevent your chances of catching it this winter.
Health officials recommend washing your hands with soap and water regularly for at least 20 seconds, particularly after using the toilet or changing diapers, before eating, preparing or handling food, or before giving yourself or someone else in your care medicine.
