A new strain of the highly contagious norovirus has reached the U.S. from Australia, and January is the peak season for the illness.
The U.S. Centers for Disease Control and Prevention (CDC) reports that the new norovirus – named GII.4 Sydney because it's believed to have started in Sydney – is currently the leading cause of norovirus outbreaks in the U.S.
In the CDC's Morbidity and Mortality Weekly Report released Jan. 25, the norovirus – not to be confused with the flu – causes epidemic gastroenteritis. Hospitalization and death associated with the infection occurs most frequently among the elderly, children, and immunocompromised patients.
An article in Time, Health and Family reports that:
- Norovirus causes 21 million cases of illness, often involving severe vomiting and diarrhea, and 70,000 hospitalizations each year in the U.S., along with 800 deaths.
- Where influenza is a respiratory illness, norovirus, which comes in five forms, favors the stomach and intestinal tract, causing inflammation that leads to pain, nausea, diarrhea and vomiting.
Time reports that the CDC says 51 percent of the cases in the U.S. were caused by person-to-person transmission, and 20 percent by contaminated food.
Most infections occur in places where large numbers of people are gathered, such as schools, nursing homes and cruise ships, where the virus can pass easily from host to host.
The CDC reports reports the new strain of norovirus was first identified in March 2012 in Australia and has since sickened people on several continents.
According to Time, historically, the GII strains have caused more severe illness than other versions of the virus, but officials at the CDC say it is too early in the season to determine if GII.4 Sydney is infecting people at higher rates than in previous years.
The norovirus season runs from November through March and cases typically peak in January.
“It’s not a completely innocuous virus and can certainly ruin a vacation,” Dr. John Treanor, chief of the Infectious Diseases Division at the University of Rochester Medical Center told Time.
Treanor told Time a group of scientists are currently testing a vaccine developed by LigoCyte Pharmaceuticals.
Preventing infection with norovirus is similar to protecting against influenza. The CDC recommends the following:
- Wash your hands carefully, especially after using the bathroom or changing diapers and before handling food.
- 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.
- Many health departments require that food handlers and preparers with norovirus not work until at least 2 to 3 days after they recover. If you were recently sick, you can be given different duties in the restaurant, such as working at a cash register or hosting.
- Immediately clean any infected or contaminated surfaces and wash laundry thoroughly 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 percent] per gallon of water) or other disinfectant registered as effective against norovirus by the Environmental Protection Agency (EPA).