A new norovirus strain identified in Australia has made its way to the United States.
The strain is GII.4 Sydney and has caused acute gastroenteritis outbreaks in four countries, including the United States, according to the Centers for Disease Control and Prevention.
In a report issued today, it is reported that between September and December of 2012, a total of 141 of the 266 norovirus outbreaks reported were caused by GII.4 Sydney.
Most, 72, of these reports were caused by person-to-person transmission; while the remaining were caused by foodborne, waterborne and unknown transmission, according to the report.
The report also states the GII.4 Sydney strain appears to have replaced the previously predominate strain, GII.4 New Orleans.
The CDC collects information on norovirus strains associated with outbreaks in the United States through an electronic laboratory surveillance called CaliciNet.
Continued surveillance will continue.
Noroviruses are a group of related viruses. Infection with these viruses affects the stomach and intestines and causes an illness called gastroenteritis. Anyone can be infected and get sick. People can also get it more than once in their life. The illness usually begins suddenly and people may feel very sick with stomach cramping, throwing up or diarrhea. Less common symptoms include low-grade fever, chills, headache, muscle aches and fatigue. People might refer to it as "food poisoning" or "stomach flu," norovirus is not related to influenza, which is a respiratory illness. Additionally, food poisoning can be caused by norovirus, but other germs and chemicals can also cause food poisoning. Norovirus can spread quickly from person to person in crowded, closed places. People can get it by eating food or drinking liquids that are contaminated with norovirus; touching surfaces or objects contaminated with norovirus and then putting hands or fingers in your mouth; having direct contact with a person who is infected.
People with norovirus illness are contagious from the moment they begin feeling sick until at least 3 days after they recover.
Currently, there is no vaccine to prevent norovirus infection. Also, there is no drug to treat people who get sick from the virus, according to the CDC.