From the Guidelines
Norovirus outbreaks should be managed by initiating investigations promptly, promoting good hand hygiene, excluding ill staff, and reinforcing effective preventive controls, as outlined in the updated guidelines 1. When dealing with norovirus, it is essential to prioritize prevention and control measures to reduce the risk of transmission.
- Key measures include:
- Initiating investigations promptly to identify the mode of transmission and possible source
- Promoting good hand hygiene, including frequent washing with soap and running water for at least 20 seconds, and using alcohol-based hand sanitizers as an adjunct
- Excluding ill staff in certain positions, such as food, child-care, and patient-care workers, until 48–72 hours after symptom resolution
- Reinforcing effective preventive controls and employee practices, such as eliminating bare-hand contact with ready-to-eat foods and proper cleaning and sanitizing of equipment and surfaces
- In terms of treatment, norovirus is typically self-limiting, and management is focused on preventing dehydration and alleviating symptoms.
- It is crucial to note that norovirus can spread easily through contaminated food, surfaces, or direct contact with infected individuals, making prevention and control measures essential to prevent outbreaks 1.
- The updated guidelines also recommend collecting whole stool specimens for diagnosis and reporting outbreaks to state and local health departments, as well as to the CDC via the National Outbreak Reporting System (NORS) 1.
From the Research
Norovirus Transmission and Prevention
- Norovirus can spread through multiple transmission routes, including person-to-person and foodborne routes 2
- The virus has a low infectious dose, high shedding titre, and environmental stability, making it difficult to prevent and control 2
- Prevention and control guidelines focus on principles of disinfection and decontamination, including hand hygiene and thorough environmental decontamination 2
Norovirus Symptoms and Treatment
- Norovirus infections are generally acute, causing symptoms such as diarrhea, nausea, and vomiting lasting for 24-48 hours 3
- However, for immunocompromised patients, norovirus gastroenteritis can last for several years and result in severe malnutrition, dehydration, electrolyte imbalance, and continuous viral shedding 3
- Treatment strategies have been suggested, including nitazoxanide, ribavirin, and enterally administered immunoglobulin, but further research is needed 3
- Ondansetron, a serotonin receptor antagonist, has been shown to reduce rotavirus- and norovirus-induced vomiting and diarrhea in children 4, 5
Norovirus Epidemiology and Virology
- Norovirus is the leading cause of gastroenteritis across all age groups, responsible for around 200,000 deaths annually 6
- The virus has high mutational rates, allowing for new variants to emerge and be more resistant 6
- The classification system divides norovirus into 10 genogroups and 49 genotypes, with GI.1 and GII.4 being the most predominant genotypes causing gastroenteritis in humans 6
- There are no specific control measures against norovirus, but common practices such as hand washing are used to prevent transmission 6