Clean hands, surfaces are main defenses against norovirus

Published on Saturday, February 1, 2025

By: Danny Barrett Jr., dlbarrett@umc.edu

A continued upswing in positive tests for norovirus in January might not necessarily be part of a new strain of the foodborne virus reported nationally, but still serves as a reminder for basic hygiene.

There were 18 inpatient cases admitted to the hospital during the month, continuing an increase noted over the final quarter of 2024, said Dr. Risa Webb, interim hospital epidemiologist and a professor in the Division of Infectious Disease. Thirteen of the cases were children, Webb said. Positive tests totaled 54 from November through January, up from 33 between August and October, Webb said.

“Recent national reports indicate there is a new strain of norovirus, though UMMC does not do strain typing to know if we are dealing with a new strain,” Webb said.

Norovirus is the most common cause of foodborne illness in the U.S. and often has an uptick in cases in winter months. It can also be spread through contaminated water or food preparation surfaces. The highly contagious stomach bug typically involves diarrhea, pain and vomiting. Closed and crowded environments are a prime breeding ground, including hospitals, long-term care facilities, child care centers, schools and cruise ships.

Unlike with other infectious diseases, hand sanitizer is not effective against norovirus, state health officials said.

“It may be used in addition to handwashing with soap and water, which has proven to be most effective,” said Dr. Renia Dotson, state epidemiologist with the Mississippi State Department of Health.

Tips for those who spend a lot of time in the kitchen include waiting at least two days after symptoms resolve to prepare or handle food and to wash fruit and vegetables.

“Separate raw oysters from ready-to-eat foods in all areas where they may come in contact with each other such as the grocery cart, refrigerator and cutting boards,” Dotson said. “Cook oysters and other shellfish thoroughly until the internal temperature reaches 145 degrees. Kitchen utensils, cutting boards and counter should be cleaned and sanitized regularly, especially after handling shellfish.”

For older adults and those with underlying medical conditions, the threat of dehydration prompts medical attention, with patients typically placed in special contact isolation, Webb said. The designation means hands should be washed with soap and water and gowns and gloves should be worn when in the room with the patient.

Hand hygiene and appropriate cleaning products are the best defenses against norovirus and other contagious infections.

“The virus is generally thought of as being easily transmissible and good hand hygiene is important to decrease the risk of infection as it is with many diseases,” Webb said. “Bleach solutions are used for cleaning hospital rooms to help ensure killing of the virus on environmental surfaces.”

Parents of young children should also make note of stomach-related illnesses during the winter, along with other common concerns of cold and flu season.

“Our concern from a pediatric standpoint is the risk of dehydration in young children,” said Dr. Anza Stanley, medical director of Batson Kids Clinic at Children’s of Mississippi. “We advise our parents to watch out for signs of dehydration inclusive of decreased or absence of saliva production, tears and wet diapers and/or urine.”

Norovirus is a common cause of stomach illnesses in children, with a peak season between November and April, Stanley said. Though the specific etiology, or set of causes, of an acute GI illness isn’t always known, prevention against them is the same for parents and children alike, she said.

“Prevention is stemmed around proper and frequent hand hygiene with soap and water, disinfecting high touch surfaces, and staying away from others when you are ill,” she said. 

Additional tips to prevent the spread of norovirus include:

• Wash hands frequently with soap and water for at least 20 seconds, especially before preparing food.
• Wash fruit and vegetables and disinfect regularly all cooking equipment such as cutting boards and the kitchen counter.
• Wear rubber gloves when handling any soiled items and disinfect the area with chlorine bleach.
• Remove any items with vomit or feces without shaking them and wash them immediately with detergent in hot water at the maximum available cycle length, then machine-dry at the highest setting.

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