Norovirus is often referred to as the “stomach bug.” But as Dr. Océane Sorel DVM, PhD, reiterates throughout the new webinar Navigating Norovirus – From Seasonal Surges to Swift Diagnosis, this innocuous-sounding “bug” can cause serious—and even deadly—illness.
Dr. Sorel, who is the Manager for Scientific Publications at Thermo Fisher Scientific, opens her presentation by clarifying why norovirus is such an important public health concern. She explains that norovirus is the most common cause of acute gastroenteritis and then shares several key statistics, such as:
- Noroviruses cause an estimated 685 million cases of illness and 200,000 deaths each year worldwide. This includes 200 million cases of illness and 50,000 deaths among children. (1)
- Researchers estimate that norovirus illness has an annual global economic impact of $60 billion due to healthcare costs and lost productivity. (1)
- In the United States, about 1 in every 15 people get norovirus illness each year. (2)
The Clinical and Molecular Epidemiology of Noroviruses
While describing the clinical and molecular epidemiology of noroviruses, Dr. Sorel points out how easily this group of non-enveloped, single-stranded RNA viruses can spread, whether that’s through direct contact with an infected person, ingesting contaminated food or water, or touching contaminated surfaces or objects.
“It is a very contagious virus and as few as 10 viral particles can cause infection,” she says.
This high infection rate means that norovirus gastroenteritis can proliferate rapidly in public places such as hospitals, nursing homes, and schools. Plus, as Dr. Sorel explains, the challenge of outbreak management is further complicated by the resistance properties of the virus particle itself. Norovirus can remain intact on surfaces for days and is relatively resistant to heat, surviving temperatures as high as 145°F. It is also resistant to many common disinfectants.
Put all of this together, and it’s easy to understand why healthcare professionals are eager to prevent and control norovirus outbreaks, particularly in settings where people with weak immune systems may develop more severe disease. During the webinar, Dr. Sorel explores the seasonal nature of norovirus outbreaks and reviews the wide range of potential infection control measures, from proper hand washing, surface cleaning, and food preparation to patient cohorting, active case finding, and rapid diagnostic testing.
Diagnostic Tests for the Detection of Norovirus Infections
In the final portion of her presentation, Dr. Sorel focuses on the importance of diagnostic tests for the swift and precise detection of norovirus infections. She takes a historical perspective, beginning with the Kaplan clinical and epidemiological criteria that predate the development of norovirus molecular diagnostics.
Today, more advanced methods, such as real-time polymerase chain reaction (RT-qPCR) assays targeting norovirus only or multiplex gastrointestinal platforms, are the preferred methods for diagnosing norovirus according to the U.S. Centers for Disease Control and Prevention (CDC), Dr. Sorel says.
Modern molecular diagnostics can be valuable for a variety of reasons, she explains. Not only do tests like these have the potential to improve the accuracy of differential diagnosis and promote antimicrobial stewardship (by distinguishing between viral and bacterial infections), but they also can be critical for streamlining surveillance to track norovirus outbreaks and detect emerging norovirus strains. In short, they are designed to enable a rapid public health response to effectively identify the source of infection, manage outbreaks, and isolate patients, especially in hospital and community settings, Dr. Sorel says.
“Recently now there’s multiplex gastrointestinal platforms that have been developed and these platforms allow testing of gastrointestinal pathogens in a single test including viral, bacterial, and parasitic pathogens,” she concludes. “They could help identify the causing pathogen with a faster turnaround because you can just test all with using one specimen and can commit and then manage the outbreaks more effectively.”
To learn more about noroviruses, including additional insights about effective strategies for managing outbreaks, watch the webinar Navigating Norovirus – From Seasonal Surges to Swift Diagnosis on demand.
For other resources on gastrointestinal pathogens, please visit our educational page here.
Océane Sorel DVM, PhD