Norovirus cases are surging the U.S., with 455 outbreaks reported since the start of September this year. More than 90 of these occurred in the first week of December — one of the highest numbers reported in any week since records began in 2012.
The true number of outbreaks is likely far higher, as only 14 states contribute to the Center for Disease Control and Prevention’s “NoroSTAT” reporting system.
Rising rates of disease are also reflected in an increasing rate of positive tests for norovirus, which the CDC uses to monitor the spread of the disease across the country. These saw a sharp rise from 10.6% in the week ending November 16 to 22.02% the week ending December 21. High case numbers have also been reported in other countries, including the U.K.
Around 2,500 outbreaks are normally reported each year in the U.S., with the bulk of cases striking between November and March and peaking in February.
Experts say the disease might be taking hold earlier this year as people socialize more readily than they have done in years.
What Is Norovirus?
Also known as “stomach flu,” “stomach bug” and the “winter vomiting bug,” norovirus is a highly contagious seasonal illness that causes gastrointestinal symptoms. In fact, it’s responsible for more vomiting and diarrhea and foodborne illness than any other disease in the country.
Norovirus spreads when small particles of infected faeces enter the body through the mouth. It’s often spread by direct contact with an infected person, touching a contaminated surface (and then the mouth), or by consuming tainted food or drinks.
Inside the body, norovirus makes its way to the gut, where it grabs on to sugars called “oligosaccharides” that line the small intestine. Once it’s there, it can inflame the intestines or the stomach, leading to violent gastrointestinal disease.
What Are The Symptoms Of Norovirus?
Norovirus commonly causes nausea, stomach pain, vomiting and diarrhea. It may also lead to certain flu-like symptoms, such as headaches, fever and body aches. Although it’s often called “stomach flu,” it’s not caused by the influenza virus.
Vomiting and diarrhea can quickly cause dehydration, so people with the disease need to try and drink water, even if it’s difficult to keep it down. Taking very small, frequent sips of water may make it easier to stay hydrated.
Symptoms appear relatively quickly after exposure to norovirus — usually within around 12 to 48 hours, per the CDC. They normally end one to three days later. But a person can still spread the disease via their faeces for several days after they feel better.
How Can I Protect Myself From Norovirus
The best way to prevent norovirus is by frequent, thorough hand-washing — especially after using the bathroom, changing a baby, or caring for someone with the disease, and before eating. Try to avoid touching your face, as this can get the virus closer to your mouth.
Keep high-touch surfaces like doorknobs and countertops clean, and wash clothes and sheets that may be contaminated at a high temperature to kill any lingering virus.
It’s also important to wash fruit and vegetables before eating them, and making sure to cook shellfish thoroughly. The CDC recommends avoiding raw shellfish like oysters entirely, as it can lead to illness and even death.
