New Norovirus Strain Behind Recent Outbreaks in US

Norovirus Outbreak

Story at-a-glance -

  • A new type of norovirus, named GII.4 Sydney, was the main culprit behind the norovirus outbreaks that sickened many Americans this past fall and winter, according to the CDC
  • Noroviruses have now surpassed rotavirus as the leading cause of gastroenteritis -- or stomach flu -- in the US
  • The CDC estimated that most of the GII.4 Sydney norovirus outbreaks resulted from direct person-to-person contact while 20 percent were foodborne and 1 percent was waterborne
  • Washing your hands with soap and water and leading a healthy lifestyle that keeps your immune system strong are the best ways to prevent norovirus infections

By Dr. Mercola

A new type of norovirus, named GII.4 Sydney because it was first detected in Australia, was the main culprit behind the norovirus outbreaks that sickened many Americans this past fall and winter.

According to a report from the U.S. Centers for Disease Control and Prevention (CDC), more than half of the 266 norovirus outbreaks reported between September and December 2012 were caused by GII.4 Sydney, which has now officially replaced the previously predominant strain GII.4 New Orleans.1

What is Norovirus?

Noroviruses are the leading cause of gastroenteritis -- or stomach flu -- in the US. They generally cause a nasty infection that leads to diarrhea, abdominal pain and vomiting within 24-48 hours of exposure.

Though the symptoms can be quite debilitating, most people recover on their own within a few days. Those most at risk of complications (typically dehydration) are infants, the elderly and those with compromised immune systems.

Norovirus is spread through direct contact with an infected person as well as through contaminated food and water. The CDC estimated that most of the GII.4 Sydney outbreaks resulted from direct person-to-person contact while 20 percent were foodborne and 1 percent was waterborne.

The elderly living in nursing homes and children in day care facilities are often among those hardest hit, due to their close proximity with others and the highly contagious nature of these viruses.

That said, noroviruses are also a major food poisoning risk and are strongly associated with so-called "complex foods" – foods that contain a number of ingredients so that the specific culprit cannot be pinpointed. Often these foods came from restaurants, which suggests contamination may have occurred during preparation or cooking – all the more reason to prepare your own foods at home!

The CDC report noted that both long-term care facilities and restaurants were among the most frequently reported settings for GII.4 Sydney outbreaks in 2012.

Norovirus Now a Greater Threat Than Rotavirus

Rotavirus is another type of virus that causes stomach flu and its related symptoms like severe diarrhea and vomiting. It used to be the leading cause of stomach flu in the United States, but now a study funded by the CDC found that since the introduction of the rotavirus vaccine, norovirus has replaced rotavirus and become the leading cause of stomach flu in US children.2

This may sound like a grand triumph for the rotavirus vaccine (which was found to be contaminated with pig DNA in 2010 and is linked to fatal bowel problems), but instead what has happened is that another similar group of viruses has taken the rotavirus' place. Are children really better off now that they're being infected with norovirus instead of rotavirus?

Hardly, and of course the conventional "solution" is to state that we mustn't worry because there are several norovirus vaccines in various stages of development, including one that is in phase III clinical trials.

A Vaccine for Every Virus?

The notion that we must develop a vaccine to protect children from every circulating virus is overly simplistic at best and potentially dangerous at worst.

The CDC stated that new norovirus GII.4 strains have emerged every two to three years, replacing previously predominant GII.4 strains. Similar to the flu vaccine, which has poorly demonstrated effectiveness, a new norovirus vaccine would need to be developed every couple of years to keep up with the rapidly changing strains.

And this is not taking into account the fact that when children are infected with several strains of rotavirus or norovirus in the first few years of life, they typically develop natural lifelong immunity. This is not the case for vaccine-acquired immunity, which typically requires "booster" shots to remain effective – if they are effective at all. According to the National Vaccine Information Center (NVIC):

"Today, even though almost all US infants receive vaccines for rotavirus, and despite efforts to improve the management of childhood rotavirus-associated diarrhea, hospitalizations of children in the U.S. with the disease have not significantly declined in the past two decades."

Certainly no parent wants his or her child to be sick with the stomach flu, but this "right of passage" provides natural immunity that will protect your child against that particular strain for life. While rotavirus and norovirus are very contagious and do cause hundreds of thousands of deaths in young children each year, this is mostly in developing countries where poverty contributes to poor sanitation, hygiene and nutrition.

In the US, rotavirus causes only 20 to 60 deaths among children under 5 each year3 while noroviruses cause just 800 deaths (among all age groups) in the US annually.4 Typically, when a child in the US contracts rotavirus or norovirus, and most do, only rest and fluids are required to recover.

Washing Your Hands is One of the Best Deterrents to the Stomach Flu

That age-old advice to wash your hands remains one of the best strategies for preventing the stomach flu. Washing your hands (and your children's hands) with soap and water if you've been in a public place and before eating is essential. Be careful not to over-wash your hands, however, as this can create tiny cuts in your hands where a virus can enter. Other common sense measures for preventing the stomach flu include:

  • Trying not to touch your eyes, mouth or nose (which is how the virus enters), especially if your hands are not clean
  • Avoiding sharing utensils, drinking cups, hand towels, etc. with others

That said, Americans actually touch about 300 different surfaces every 30 minutes … so it's rather unrealistic to think that you can avoid ever coming into contact with an infectious virus. But this needn't send you into panic mode, as just because you're exposed to a virus does not mean you will get sick. The determining factor? The health of your immune system! So, along with the practical precautions mentioned above, preventing the stomach flu involves keeping your immune system healthy by following these five steps to boost your immune system health.

What to do if You Get the Stomach Flu

Even if you're very healthy and very careful, there's a good chance that you (and your kids) may come down with a case of the stomach flu at some point or another. If this happens, make sure the vomiting and diarrhea does not cause you to become dehydrated, as that can cause serious problems, even death.

If you begin to become dehydrated, it is vital that you go to an emergency room for evaluation. This is especially important for children who can become dehydrated much quicker than adults. At the emergency room they will typically insert an IV into your vein and provide rehydration fluids directly into your bloodstream, which rapidly eliminates the danger of dying from fluid loss.

Initially, however, the following simple protocol is often very effective in clearing up the stomach flu long before you get to this point. If you have thrown up, put your stomach at complete rest for at least three hours. That means you should have absolutely nothing to eat or drink, including no water nor the folklore favorite of crackers and soda.

Once three hours have passed and no further vomiting has occurred then small amounts of water can be sipped slowly. Again, only after your stomach has stabilized and no additional vomiting is occurring, small amounts of water can be sipped and if that is tolerated you can gradually increase the water. Do this for one to two hours and if that is tolerated then you are ready for the final phase … large doses of a high-quality probiotic, taken every 30 to 60 minutes until you feel better.