Is a New Norovirus Strain Behind the Surge of Infections in the US? Experts Weigh In

A brand new pressure of norovirus makes up nearly all of outbreaks nationwide—and it could provide a proof for the steep rise in infections over the previous month.

The brand new norovirus pressure, referred to as GII.17[P17], was accountable for practically 70% of all norovirus outbreaks from September 2024 by way of the tip of December 2024, based on information from the Facilities for Illness Management and Prevention.

The CDC recorded 91 norovirus outbreaks from state well being departments for the week ending Dec. 5—the best quantity recorded lately. Norovirus on cruise ships additionally reached higher-than-normal ranges in December, with at the very least 6 reported norovirus outbreaks on vessels.

Norovirus—significantly the GII.17 pressure—is “all over the place” proper now, Jan Vinjé, PhD, head of the CDC’s Nationwide Calcivirus Laboratory, lately advised CBS Information.

“It’s too early to inform if this pressure is related to extra extreme norovirus illness,” Vinjé mentioned, “however doubtless decrease inhabitants immunity is the rationale for the early surge of an in any other case seasonal improve of this virus.”

This is what you might want to know concerning the new norovirus pressure, whether or not it is actually inflicting an uncommon uptick in circumstances, and how you can shield your self from sickness.

It is vital to notice that the brand new norovirus pressure, although newer, is not technically model new,

“The GII.17 pressure emerged in 2014-15 and has unfold worldwide,” infectious illness professional Amesh A. Adalja, MD, a senior scholar on the Johns Hopkins Heart for Well being Safety, advised Well being.

Nevertheless, the pressure solely rose to dominance in norovirus outbreaks over a 12 months in the past; between Sept. 1, 2023 by way of Aug. 31, 2024, GII.17 accounted for 109 norovirus outbreaks.

In the meantime, the earlier main pressure, GII.4—which had dominated earlier norovirus outbreaks since 2012, based on Vinjé—solely made up 84 outbreaks. Up to now this 12 months, from Sept. 1, 2024 by way of Dec. 31, 2024, GII.17 has made up 39 outbreaks; GII.14 has accounted for 4.

It is doable that, with GII.17 being a more recent pressure, there is not as a lot built-up inhabitants immunity to it, doubtlessly resulting in extra infections.

Thomas Russo, MD, professor and chair of infectious ailments on the College at Buffalo, agrees. “If somebody has developed some immunity in opposition to norovirus from prior infections, this variant might be able to evade it,” he advised Well being.

However extra information is required to parse out whether or not GII.17 is actually behind a surge in circumstances.

Moreover, GII.17 and GII.14 aren’t the one norovirus strains. There are quite a few strains of norovirus, which implies individuals can (and do) get norovirus many occasions of their lives. Whilst you can develop safety in opposition to particular sorts of norovirus, it’s not identified how lengthy that safety lasts—and being contaminated with one sort of norovirus might not shield you from different sorts.

“It’s not dissimilar to what we see with COVID,” mentioned Russo. “For those who’re contaminated, you’ll have a level of immunity however, in case you get a variant that evolves and evades that immunity, that can improve the pool of vulnerable people.”

The brief reply is not any. “There’s no clinically significant distinction with this pressure,” mentioned Adalja.

Meaning GII.17 is more likely to trigger the everyday norovirus signs like diarrhea, vomiting, nausea, and abdomen ache, together with fever, headache, and physique aches.

Suggestions for norovirus prevention and remedy additionally do not change with a more recent norovirus pressure, Dr. Russo mentioned.

For prevention, meaning frequently washing your arms nicely with cleaning soap and water. (Hand sanitizer isn’t very efficient in opposition to norovirus.) Washing your garments in scorching water might also be useful. It’s a good suggestion to attempt to keep away from people who find themselves clearly sick, too, mentioned Russo.

There isn’t any particular remedy for norovirus, however Dr. Russo recommends doing all of your finest to remain nicely hydrated. “Taking small sips of liquids might provide help to to maintain them down,” he mentioned. You probably have a fever or physique aches, an OTC remedy like acetaminophen might also assist.

Dr. Russo stresses the significance of doing what you’ll be able to to decrease your threat of norovirus. “Norovirus isn’t enjoyable,” he mentioned. “It’s 24 to 48 hours of distress.”