Norovirus In MD: 5 Things To Know About The Stomach Bug

MARYLAND — Public health officials in Maryland are keeping an eye on a steady increase in cases of the highly contagious norovirus in nearby states, the stomach bug that is the leading cause of food-borne illnesses in the United States.

COVID-19 cases in Maryland and nationwide continue to fall, but norovirus cases have ticked up, according to data from the Centers for Disease Control and Prevention.

Neighboring Virginia has reported 12 norovirus outbreaks so far this year, the CDC said. No cause has been listed, but health authorities say it can easily contaminate food and water.

The dreaded norovirus is often referred to as a "stomach flu," but officials said it is not related to influenza. The sticky bug causes severe vomiting and diarrhea and can affect anyone of any age. But there are precautions you can take to avoid the virus' nasty effects.

Norovirus is the scientific name for the bouts of vomiting and diarrhea that many times will sicken entire households before running their course. Outbreaks were nearly nonexistent at the height of the COVID-19 pandemic, according to federal health data, and experts believe it’s because Americans largely stayed away from the places where norovirus spreads.

It takes only a few of the billions of microscopic norovirus particles to make a person sick.

Norovirus is spread a number of ways, including through vomit and feces particles that may remain on a person’s hands or on surfaces during food preparation. It also can come from contaminated water that is used for irrigation of fruit and vegetable crops — or if food, such as oysters, is harvested in contaminated water.

The most recent example of the latter: As of Monday, 91 people had been sickened after eating oysters distributed in at least 13 states, including Florida, New Jersey and New York. The U.S. Food and Drug Administration said more states could be affected from further distribution.

But even before the oyster-related outbreaks, norovirus was making a comeback. Data collected by the CDC's National Outbreak Reporting System shows that 448 norovirus outbreaks were reported from August 2021 to March 2022, compared with 78 outbreaks during the same period the previous year.

From August 2021 to March 10, 2022, at least 448 known cases of norovirus were reported in the U.S., according to the CDC.

State health departments in Massachusetts, Michigan, Minnesota, Nebraska, New Mexico, Ohio, Oregon, South Carolina, Tennessee, Virginia, Wisconsin and Wyoming reported norovirus cases during the most recent seven-month period.

Agencies aren’t required to participate in the norovirus surveillance system, which the CDC says makes it impossible to estimate the true number of norovirus cases. Many cases don’t require a visit to the doctor’s office, and most hospitals and other health care providers don’t test for it, the agency says.

Symptoms such as vomiting, diarrhea, nausea and stomach cramps usually appear from 24 to 48 hours after exposure. People are contagious from the point they start feeling ill and for up to two weeks.

The best thing to do is to prevent its spread. Wash your hands the right way, for at least 20 seconds under hot, soapy water, taking care to scrub under nails and between your fingers. Also, clean up food preparation surfaces with diluted bleach.