Just a Stomach Bug?

Norovirus infections number in millions annually

(RxWiki News) Nausea, vomiting, diarrhea — these unpleasant symptoms are often brushed off as "the stomach bug" and ignored. But in many cases, a norovirus infection may be the real culprit.

A new study looked at norovirus in the US and found that it leads to millions of infections each year.

This study also showed that young children and older adults have the greatest risk for hospitalization and death related to the virus.

To prevent the spread of norovirus, these researchers suggest carefully washing hands, especially after using the bathroom, after changing diapers and before handling food.

"Wash your hands before handling food."

Norovirus, which is spread through contact with an infected person, surface or food, may occur many times during a person's life without serious problems. But the virus can lead to hospitalization and even death, especially among certain age groups.

A team of researchers led by Aron J. Hall, DVM (Doctor of Veterinary Medicine), an epidemiologist with the Centers for Disease Control and Prevention (CDC), examined the presence of norovirus by looking at a variety of data.

These researchers relied upon information from several large, national surveys, including the National Ambulatory Medical Care Survey (NAMCS) and the CDC's Foodborne Diseases Active Surveillance Network (FoodNet).

The researchers found that norovirus causes an average of 19 to 21 million total illnesses each year in the United States.

This accounts for an estimated 1.7 to 1.9 million annual doctor visits and 400,000 annual emergency department visits. Furthermore, approximately 56,000 to 71,000 hospitalizations occur each year due to norovirus.

Dr. Hall and team determined that norovirus causes an average of 570 to 800 deaths annually. 

This study showed that people over the age of 65 have the greatest risk of death related to norovirus, and that children under the age of 5 receive the most medical care for norovirus. 

The researchers also estimated that, based on these results and a life expectancy of 79 years, the average US resident would contract norovirus five times during their lifetime. The average person's risk for death from the infection was found to be 1 in 5,000 to 7,000.

Dr. Hall and team noted that, though norovirus exists throughout the year, the virus peaks during the winter months. 

"This review facilitates identification of key groups that would benefit from prevention strategies aimed at controlling norovirus and provides the grist for development of appropriate interventions, including vaccines," the study authors wrote.

The authors also noted that an ideal vaccine for norovirus should be safe and effective for both older adults and young children, the two groups at greatest risk of major health problems from an infection.

Norovirus is commonly a foodborne virus, and steps to properly manage, cook and store food can help prevent infection.

"Carefully wash fruits and vegetables before preparing and eating them. Cook oysters and other shellfish thoroughly before eating them," the CDC recommended.

In an interview with dailyRx News, Jocelyn Ang, MD, Infectious Disease Specialist at the DMC Children's Hospital of Michigan, provided some other tips for preventing the spread of norovirus, including washing hands with soap and water for a minimum of 20 seconds. 

"Ill staff healthcare workers, food handlers and childcare workers should be excluded from work until 48 to 72 hours after resolution of their symptoms," Dr. Ang recommended.

This study was published in the CDC's Emerging Infectious Diseases journal on July 10. No conflicts of interest were reported.

Review Date: 
July 9, 2013