Ask the Doctors: Norovirus easy to spread, difficult to kill

Dear Doctors: When my family tried to visit my parents at their assisted-living facility, we were turned away. I thought COVID-19 was going to be the reason, but it was because of a norovirus outbreak. What is that? Is it really so contagious?

Dear Reader: Norovirus refers to a group of viruses that are the leading cause of gastrointestinal illness in the United States, sickening 21 million people a year and sending more than 100,000 to the hospital.

Each year, these viruses cause 900 deaths, most in adults 65 and older.

Norovirus is shed in an infected person’s feces and is extremely contagious.

If you have it and don’t thoroughly wash your hands after a bowel movement, you can spread it to everything you touch.

Someone can become infected by accidentally ingesting the minuscule particles of feces that are left behind on a surface you touched or through person-to-person contact or consuming food or drink you prepared or handled.

The virus is present in vomit, too, which adds another layer of risk when caring for or living with someone who’s ill.

Some people infected with norovirus don’t become sick but still can spread the virus.

Symptoms begin 12 hours to two days after exposure, often suddenly. The most common include nausea, repeated vomiting, stomach cramps and fatigue. Less often, people experience headache, low-grade fever, muscle aches and chills.

Though a misery-inducing experience, it’s usually not life-threatening. But it can be severe in vulnerable populations, such as infants, young children, older adults and those with a weakened immune system.

Lab tests can detect noroviruses in a stool sample, but diagnosis usually is by the distinctive symptoms.

There’s no cure besides time. The focus is on rest, managing discomfort, staying hydrated and meticulous hygiene to stop the spread. For those with a healthy immune system, recovery usually takes several days.

Norovirus outbreaks are notoriously difficult to control, particularly in group settings such as hospitals, schools, cruise ships, nursing homes and assisted-living facilities.

Once an outbreak takes hold, it takes time and vigilance to eradicate. This includes repeatedly disinfecting every surface that might have been contaminated and ensuring that everyone in the household or facility follows a strict regimen of frequent and thorough handwashing.

Disposable gloves and paper towels should be used to clean up after a sick person, and they should be bagged before going into the trash. Infected people should stay home and avoid contact with others.

Dr. Eve Glazier and Dr. Elizabeth Ko are internists at UCLA Health.