New Strain of Norovirus - the Winter Vomiting Bug - On the Rise
A new norovirus strain was detected last year in Australia and has reached the United States.
Although the flu is on everyone’s minds this season, the winter vomiting bug, or the norovirus, is also making its rounds.
The U.S. Centers for Disease Control and Prevention (CDC) reports that the norovirus causes about 70,000 hospitalizations and 800 deaths each year, mostly in young children and the elderly.
Some of the virus' common symptoms include nausea, vomiting, diarrhea and stomach pains. The CDC points out that the norovirus is often referred to as the stomach flu, but it is unrelated to influenza.
“The norovirus, which many people call the stomach flu, is widespread this year,” said Katinka Podmaniczky, assistant director of communications for the Boston Public Health Commission. “We encourage everyone to take simple precautions to protect themselves and others, like washing hands frequently and staying home if you feel sick.”
In Boston, right now about 2.5 percent of all emergency room visits are related to accute gastrointenstinal problems, which may or may not be caused by a norovirus, according to a Health Commission report. This time last year, that number was just over 3 percent. The commission did not have data for the total number of people reporting GI issues outside the ER.
This year's strain
What's different this year is the norovirus is mostly a new strain, GII.4 Sydney. It was first detected last year in Australia, then the U.K. and sickened over a million people. It has now reached the United States and this new strain appears to be taking over.
Of norovirus cases reported from September to December, 54 percent have been identified as GII.4 Sydney, according to recently released data.
The first norovirus outbreak was reported in Ohio in 1968. Today, approximately 21 million illnesses are attributable to norovirus in the U.S. each year, reports the CDC. Of those, approximately 25 percent can be attributed to foodborne transmissions. The norovirus can also spread quickly in closed places like daycare centers, nursing homes, schools, and cruise ships.
Avoiding the Norovirus
This hardy virus is extremely contagious. The BBC reports that norovirus is one of the few infections you can catch from a toilet seat. The virus can survive temperatures as high as 140°F, which makes eating raw fish, such as oysters, particularly dangerous.
Noroviruses can live in vomit or stool even before a person experiences symptoms, and up to two weeks after symptoms disappear. People are most contagious when they experience symptoms and during the first three days after recovery, reports the CDC.
While the noroviruse is on the rise, seasonal influenza—in particular, influenza A—remains the largest health problem in Boston this season, with more than 1,220 cases reported since Oct. 1, according to the Health Commission’s latest report, dated Jan. 19. However, there has been a slight decrease in cases from earlier this month, when Mayor Thomas Menino declared a public health emergency.
There is no treatment or vaccine against norovirus. To help prevent contamination, the CDC recommends the following tips:
5 Tips to Prevent Norovirus From Spreading
1. Practice proper hand hygiene
Always wash your hands carefully with soap and water:
- after using the toilet and changing diapers, and
- before eating, preparing, or handling food.
- Alcohol-based hand sanitizers can be used in addition to hand washing. But, they should not be used as a substitute for washing with soap and water.
2. Wash fruits and vegetables and cook seafood thoroughly.
- Carefully wash fruits and vegetables before preparing and eating them.
- Cook oysters and other shellfish thoroughly before eating them.
- Be aware that noroviruses are relatively resistant. They can survive temperatures as high as 140°F and quick steaming processes that are often used for cooking shellfish. Food that might be contaminated with norovirus should be thrown out.
- Keep sick infants and children out of areas where food is being handled and prepared.
3. When you are sick, do not prepare food or care for others
- You should not prepare food for others or provide healthcare while you are sick and for at least 2 to 3 days after you recover.
- This also applies to sick workers in schools, daycares, and other places where they may expose people to norovirus.
4. Clean and disinfect contaminated surfaces
- After throwing up or having diarrhea, immediately clean and disinfect contaminated surfaces.
- Use a chlorine bleach solution with a concentration of 1000–5000 ppm (5–25 tablespoons of household bleach [5.25%] per gallon of water) or other disinfectant registered as effective against norovirus by the Environmental Protection Agency (EPA).
5. Wash laundry thoroughly
Immediately remove and wash clothes or linens that may be contaminated with
vomit or stool (feces).
- handle soiled items carefully without agitating them,
- wear rubber or disposable gloves while handling soiled items and wash your hands after,
- and wash the items with detergent