The norovirus, also known as the stomach flu, is spreading rapidly in the United States, with the rate of positive tests hitting a seasonal high, according to the Centers for Disease Control and Prevention (CDC). The norovirus is a highly contagious virus that causes gastrointestinal symptoms such as diarrhea, vomiting, nausea, and stomach pain. It is not related to the influenza virus, but it is sometimes referred to as the stomach flu. The symptoms can also include mild fever and aches.
Just a few virus particles are enough to make someone sick, and they spread easily via hands, surfaces, food, and water. An infected person can transmit the virus for days after they’re feeling better, potentially even up to two weeks, according to the CDC.
The virus is the leading cause of foodborne illness in the country, and food can get contaminated if fruits or vegetables are grown or washed with contaminated water. Oysters, too, pose a norovirus risk if they are harvested from contaminated water.
In December, a multistate outbreak was linked to raw oysters from Texas, with nearly 300 norovirus cases reported.
The Midwest region had the highest average test positivity rate for norovirus as of Saturday, at over 19% — higher than any other week in the last year. The CDC tracks norovirus outbreaks via a network of 14 state health departments, and the most recent tally suggests state health departments reported 25 outbreaks as of the first week of January, the most since May. Between August and early January, a total of 225 norovirus outbreaks were reported to the CDC, compared to 172 during the same period last season.
Preventing the Virus’ Spread
Prevention measures implemented during the COVID-19 pandemic were likely effective in preventing norovirus outbreaks, but as pandemic restrictions have relaxed, the number of norovirus outbreaks has returned to levels similar to pre-pandemic years, according to Kate Grusich, a CDC spokesperson. "Norovirus outbreaks and reported cases from both state health departments and clinical laboratories are increasing but remain within the expected range for this time of year," she said.
Most norovirus outbreaks in the U.S. happen between November and April. On average, the country sees around 20 million cases per year, with nearly 110,000 hospitalizations and 900 deaths, mostly among those who are 65 and older. There is no treatment for norovirus, but the CDC recommends drinking lots of fluids to prevent dehydration. The illness typically resolves within a few days.
In England, norovirus rates this year are exceptionally high, according to the UK Health Security Agency. As of the end of January, lab reports of norovirus were 66% higher than the average over the five seasons before the COVID pandemic. The agency primarily attributes the increase to higher reporting among people 65 and older.
To prevent norovirus, it is important to wash your hands frequently with soap and water, especially after using the bathroom, changing a diaper, and before eating or preparing food. The CDC also recommends avoiding close contact with people who are sick, and cleaning and disinfecting surfaces that may be contaminated with norovirus. If you have norovirus, you should stay home and avoid close contact with others to prevent spreading the virus.
It is also essential to avoid consuming raw or undercooked oysters, and to wash fruits and vegetables thoroughly before eating them. If you are experiencing symptoms of norovirus, it is best to seek medical attention, especially if you have a weakened immune system or if you are dehydrated.
In conclusion, the norovirus is spreading rapidly in the United States, with the Midwest region having the highest average test positivity