Norovirus On the Rise: How to Avoid this ‘Stomach Flu’
Norovirus – a common and contagious virus that causes vomiting and diarrhea is on the rise throughout the United States.
Recent data from the Centers for Disease Control and Prevention has noted that over 15% of norovirus tests are coming back positive. This is the highest positivity rate since March 2022.
Each year it is estimated that this virus causes between 19 and 21 million total illnesses throughout the United States, almost 500,000 emergency department visits, and about 900 deaths – mostly among adults over 65 years old.
Norovirus is an illness that tends to have a wintertime seasonality with an uptake usually around February. While current data suggests that we are currently within the seasonal range, the CDC reports that this is an increase compared to the past years.
What is norovirus?
Norovirus is a viral infection that is one of the most common types of gastroenteritis – a condition that causes nausea, vomiting, diarrhea, and abdominal upset.
“While many viruses and illnesses cause a fever, norovirus does not always cause one,” says Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center in Tennessee.
Many of the symptoms last for just two or three days and while it may come on and leave quite quickly in comparison to other viruses, during the time the symptoms are present, it can be extremely uncomfortable.
“It is sometimes called the ‘stomach flu’ or ‘stomach bug’ but is not related to the flu,” said Dr. Rachael Lee, UAB Health Care Epidemiologist and associate professor with the UAB Division of Infectious Diseases.
Lee explains that many of the symptoms present quite quickly after being infected. “Following exposure, a person will usually develop symptoms 12-48 hours later and most people will get better within 1-3 days.”
How do you get it?
While each virus has a different ability to transmit, norovirus is a highly transmissible infection. According to the CDC , each person who is infected with norovirus sheds billions of viral particles.
While billions of viral particles are being shared by everyone who has it, Schaffner says that “only one viral particle is needed to infect another person.”
He goes on to explain that when one person in a household or a family has this condition, it is almost inevitable that everyone else will get it as well.
This is a virus that is not only passed through respiratory pathways but also environmental pathways as well.
How do you prevent it?
“The number one way to prevent transmission of this virus is practice proper hand hygiene: wash your hands after you go to the bathroom, before you eat or prepare food, and when they are visibly soiled,” Lee tells Healthline.
If you are around a family member who is sick or taking care of someone wiping down surfaces that are shared can also help decrease transmission of this virus within a household.
Lee explains that hand sanitizer which tends to be alcohol-based can prevent illness from many viruses, but it may not work that well for norovirus. She says that the best way to wash your hands is with “soap and water for at least 20 seconds.”
How to treat it
While this virus tends to be short-lived, treatment is based on symptomatic care.
“Keep up your fluids – particularly clear fluids or those with a little bit of carbonation,” explained Schaffner.
While having the symptoms of norovirus can be uncomfortable, they tend to be very short-lived and something that many people recover from in just a few days with over-the-counter medications. Hydration is one of the most important things you can do to help prevent dehydration – the biggest complication of this illness.
Rising cases
The United States is not alone in this increase in norovirus cases. The UK Health Security Agency recently reported that norovirus cases are approximately 66% higher this season than the five-season average of the same period before COVID-19.
While the virus can affect people in large groups, we are starting to see bigger clusters of individuals getting sick. Most recently a school of K-8 students in Livonia, Michigan had to shut down as over 115 students and staff members contracted this virus, according to reports.
How it is diagnosed
Norovirus is diagnosed via testing stool samples.
Since many people do not get tested, experts can only estimate how many norovirus cases occur in the U.S. every year.
Some people find getting tested embarrassing while others only have symptoms for a few days and do not go to seek medical care during that time.