You are using an outdated browser. Please upgrade to the latest version for the best experience. Upgrade your browser now.
Skip Navigation

Second Opinion: Should You Be Worried About the Norovirus Spike?

Blue Shield’s Dr. Nina Birnbaum explains why norovirus is so contagious and how to protect yourself.

This story is also available in Spanish.

Nina Birnbaum headshot
Dr. Nina Birnbaum, Blue Shield of California

Cases of the norovirus, a highly contagious stomach bug, have surged in recent weeks nationwide, and especially in the Northeast and West, according to the Centers for Disease Control and Prevention. The virus, which can cause diarrhea, nausea, vomiting and stomach pain, typically ramps up in the fall and peaks in the late winter or early spring — and like many infections, is most dangerous to infants and elders.

“The rise in norovirus cases is what we expect this time of year,” said Dr. Nina Birnbaum, medical director of Health Transformation at Blue Shield of California. “The most effective way to avoid the virus is to practice good hygiene — keep your hands and surfaces clean, especially if you have to care for someone who is sick. Also, be alert to your own symptoms and those of others around you. If you're sick, stay home.”

We spoke with Dr. Birnbaum to learn more about norovirus, how to prevent it and what to do if the virus catches you.

How does norovirus spread?

Norovirus is transmitted either from person to person, or via contaminated water and food. It’s typically spread via fecal particles and can also be transmitted from the vomit of an infected person. Most often, particles rest on surfaces that have been touched by an infected person, then the virus finds new hosts when others contact those surfaces and subsequently touch their mouths.

Why is the virus so contagious?

Norovirus is a hearty germ. People with the illness shed billions of virus particles which can linger on surfaces for days or even weeks. Yet it only takes 20 or fewer particles for an infection to take hold in a new host. Those who are sick are most contagious when symptoms are worst and the first few days after, but can shed virus for a couple weeks.

What can I do to prevent contracting norovirus?

Keep sick members of your household isolated as much as possible, and spray down surfaces with a bleach solution. Avoid sharing towels, dishes, utensils and other objects that would touch your mouth and face. Thorough hand-washing with warm water and soap is important – and more effective than hand sanitizers. When you wash your hands, you remove the virus with running water, whereas using anti-bacterial hand sanitizer might not fully kill all of the microscopic particles on your hands.

What if I get the norovirus?

The bug is rarely life-threatening and usually resolves itself in one to three days. Remember to stay hydrated and isolate yourself to avoid spreading the virus to others. It’s always a good idea to get advice from your healthcare provider. The goal is to stay well-hydrated while your immune system fights the virus. Blue Shield of California members can also get advice through Teladoc or our NurseHelp hotline.

How does the norovirus compare with respiratory illness?

The norovirus can cause a lot of discomfort, but most people are better in a few days. Generally, respiratory illnesses such as influenza, COVID-19 and respiratory syncytial virus (RSV), are more dangerous. On average, the norovirus causes about 900 deaths a year in the United States, according to the Centers for Disease Control. Yet the flu season will lead to 18,000 to 53,000 deaths, the agency estimates. In comparison, approximately 66,000 people died from COVID in the last year.

“During this season when the norovirus and respiratory illnesses thrive, just use common sense,” Dr. Birnbaum advised. “Stick to the basics – vaccines where available and good hygiene practices will go a long way toward keeping you healthy.”