From the Guidelines
Influenza (flu) and norovirus are distinct viral illnesses with different symptoms, transmission methods, and treatments, with the flu being a respiratory illness and norovirus being a gastrointestinal illness. The key differences between the two illnesses are:
- Symptoms: Influenza is characterized by fever, body aches, fatigue, cough, and sore throat, with symptoms typically lasting 5-7 days 1, while norovirus causes sudden onset of vomiting, watery diarrhea, and stomach cramps, usually lasting 1-3 days 1.
- Transmission: Both viruses spread through person-to-person contact, but norovirus is particularly contagious and often causes outbreaks in closed settings like cruise ships and nursing homes 1.
- Treatment: Flu can be prevented with annual vaccines and treated with antiviral medications like oseltamivir (Tamiflu) if started within 48 hours of symptom onset, while norovirus treatment focuses on preventing dehydration through fluid replacement 1.
- Prevention: Prevention for both includes frequent handwashing, but norovirus requires special attention to disinfecting surfaces with bleach-based cleaners as it's resistant to many standard disinfectants 1.
- Complications: While flu can lead to serious complications like pneumonia, especially in vulnerable populations, norovirus rarely causes severe illness beyond dehydration 1.
Some important considerations for norovirus outbreaks include:
- Exclusion and isolation of infected persons to minimize transmission 1
- Disinfecting surfaces with bleach-based cleaners to reduce environmental contamination 1
- Frequent handwashing with soap and water to prevent person-to-person transmission 1
- Reporting outbreaks to state and local health departments to facilitate investigation and control measures 1
Overall, understanding the differences between influenza and norovirus is crucial for effective prevention, diagnosis, and treatment of these illnesses, and for reducing the risk of complications and outbreaks.
From the Research
Differences between Influenza and Norovirus Infections
- Influenza is an acute respiratory illness caused by the influenza A, B, and C viruses, affecting the respiratory system 2, 3
- Norovirus, on the other hand, causes an estimated 18% of all cases of acute gastroenteritis worldwide, primarily affecting the gastrointestinal system 4, 5
Symptoms and Complications
- Influenza is associated with high mortality during pandemics, epidemics, and sporadic outbreaks, and can lead to complications such as chronic respiratory disease 2, 3
- Norovirus infection can lead to chronic diarrhea in immunocompromised patients, necrotizing enterocolitis (NEC) in preterm infants, and other complications such as benign infantile convulsions with gastroenteritis (BICG) 4
Transmission and Prevention
- Influenza vaccination is the most effective method for preventing influenza infection and its complications 3
- Norovirus infection can be prevented through strict public health interventions, such as those implemented during the COVID-19 pandemic, which led to a 49% decrease in norovirus outbreaks in the United States 6
- Currently, there are no approved vaccines or antiviral therapies available to treat or prevent norovirus illness, although several candidate vaccines are in clinical trials 5