From the Guidelines
Norovirus is a highly contagious, nonenveloped, single-stranded RNA virus that causes gastroenteritis, characterized by sudden onset of vomiting, watery diarrhea, abdominal cramps, and sometimes low-grade fever. The virus is classified into the genus Norovirus of the family Caliciviridae, as stated in the updated norovirus outbreak management and disease prevention guidelines 1. Treatment is primarily supportive, focusing on preventing dehydration through oral rehydration solutions like Pedialyte or homemade solutions. There are no specific antiviral medications for norovirus, and antibiotics are ineffective since it's viral. Most people recover within 1-3 days without complications, although more prolonged courses of illness can occur, particularly among young children, elderly persons, and hospitalized patients 1.
Key Characteristics of Norovirus
- Norovirus is shed primarily in the stool but also can be found in the vomitus of infected persons 1
- The virus can be detected in stool for an average of 4 weeks following infection, although peak viral shedding occurs 2–5 days after infection 1
- Norovirus is extremely contagious, with an estimated infectious dose as low as 18 viral particles 1
- Transmission occurs by three general routes: person-to-person, foodborne, and waterborne 1
Prevention and Control
- Prevention includes thorough handwashing with soap and water (hand sanitizers are less effective) 1
- Disinfecting surfaces with bleach-based cleaners, washing contaminated clothing and linens, and avoiding food preparation for others while sick and for 48 hours after symptoms resolve 1
- Those infected should stay home from work or school to prevent spreading the virus, and exclude ill staff in certain positions until 48–72 hours after symptom resolution 1
- In closed or institutional settings, isolate ill residents, patients, and passengers until 24–48 hours after symptom resolution 1
From the Research
Definition and Symptoms of Norovirus
- Norovirus is an acute infection that causes symptoms such as diarrhea, nausea, and vomiting, typically lasting for 24-48 hours 2.
- However, in immunocompromised patients, norovirus gastroenteritis can persist for several years, leading to severe malnutrition, dehydration, electrolyte imbalance, and continuous viral shedding 2.
- Common signs and symptoms associated with viral gastroenteritis, which is often caused by norovirus, include abdominal pain, diarrhea, and dehydration 3.
Transmission and Outbreaks
- Norovirus is highly contagious and is the leading cause of nonbacterial outbreaks of gastroenteritis worldwide 4.
- The virus can spread through the fecal-oral and contact routes, and asymptomatic individuals may act as reservoirs and facilitate transmission 4.
- Outbreaks of norovirus can occur in various settings, including nurseries, schools, hospitals, and care homes, causing major disruption 5.
Treatment and Prevention
- Several treatment strategies have been suggested for norovirus gastroenteritis, including nitazoxanide, ribavirin, and enterally administered immunoglobulin, but further research is needed to determine their effectiveness 2.
- Infection control procedures, such as good hand hygiene and limiting contamination of food, water, and the environment, are effective in preventing the spread of norovirus if properly implemented 5.
- Oral rehydration therapy is an effective treatment for mild or moderate dehydration caused by viral gastroenteritis, including norovirus 6.