Infectious gastroenteritis is a group of diseases presenting with acute gastrointestinal symptoms (diarrhea, vomiting, abdominal pain, fever) caused by pathogens such as viruses and bacteria, and includes both viral and bacterial types.
In winter, it's mainly Norovirus, Rotavirus, Adenovirus (types 40/41) It is viral gastroenteritis.

🦠 Norovirus(Noro)

■ Seasonality
It peaks in winter and is the most common causative virus across all age groups.
■ Symptoms
vomiting Observed in cases with a score of 60% or higher
Diarrhea, abdominal pain, and fever are also present.
■ Post-infection immunity
Antibodies are Several months to a year Sustainability
・Re-infection Occurring frequently within six months to several years
Genetic types are diverse, and long-term immunity is not established.

🍼 Rotavirus

■ Seasonality
After the vaccine rollout Pediatric respiratory illness in winter。
■ Symptoms
vomiting 60% or higher
・Watery diarrhea, high fever, and a tendency to become severe in infants and young children.

🍼 Rotavirus vaccine effectiveness
● Preventive effect of severe rotavirus gastroenteritis: 60-97%
● High effectiveness continues until around 2 years of age.
● Significant preventive effect from ages 3 to 5 continues, but decreases with age
● In US data, Efficacy lasts up to 3 to 7 years after vaccination.
Infection itself cannot be completely prevented, and breakthrough infections can occur in mild cases or when immunity is low.

🧪 Immunity after natural rotavirus infection
Antibodies (IgA) are Lasting over 1 year
However Reinfection within a few years
Even with natural infection, it "prevents severe illness but not infection itself."

👶 Adenovirus (Adeno: types 40/41)

■ Seasonality
It tends to increase from winter to spring.
■ Symptoms
・Nausea, diarrhea, and fever were present, and there was no data indicating a lack of vomiting.
■ Post-infection immunity
Antibodies are Lasting for several years
However Type-specific
You can be reinfected with different types.
Even with the same type, reinfection is possible due to weakened immunity or the emergence of new strains.

❄️ Summary

Winter acute gastroenteritis is not just Norovirus.
Noro, Rota, Adeno The three are the main causes, and all of them present with vomiting, diarrhea, and fever.
Rotavirus vaccine It greatly prevents severe illness, is strongest until age 2, and the effect lasts until age 3-5.。
Norovirus, rotavirus, and adenovirus are all Reinfection can occur. Therefore, prevention such as hand washing and disinfection is important.

📚 Literature

Epidemiology and Symptoms of Norovirus, Rotavirus, and Adenovirus

• Thongprachum A et al. “Epidemiology of Gastroenteritis Viruses in Japan: Prevalence, Seasonality, and Outbreaks.” Journal of Medical Virology. 2016
• Thongprachum A et al. “A Four-Year Study of Viruses That Cause Diarrhea in Japanese Pediatric Outpatients.” Journal of Medical Virology. 2015
• Öner SZ et al. “Prevalence of Rotavirus and Adenovirus in Patients with Acute Viral Gastroenteritis in Denizli, Turkey, 2017–2021.” Journal of Medical Virology. 2022
• Wang G et al. “Age-Specific Spectrum of Etiological Pathogens for Viral Diarrhea Among Children in Twelve Consecutive Winter–Spring Seasons (2009–2021) in China.” Journal of Medical Virology. 2022
• Blacklow NR et al. “Viral Gastroenteritis.” New England Journal of Medicine. 1991
• Narkeviciute I et al. “Peculiarities of Norovirus and Rotavirus Infections in Hospitalized Young Children.” Journal of Pediatric Gastroenterology and Nutrition. 2008

Rotavirus vaccine effectiveness

• Clark A, et al. “Efficacy of Live Oral Rotavirus Vaccines by Duration of Follow-Up: A Meta-Regression of Randomized Controlled Trials.” The Lancet Infectious Diseases. 2019
• Diallo AO et al. “Rotavirus Vaccine Effectiveness Against Severe Acute Gastroenteritis: 2009–2022.” Pediatrics. 2024
• Payne DC et al. “Long-Term Consistency in Rotavirus Vaccine Protection: RV5 and RV1 Vaccine Effectiveness in US Children, 2012–2013.” Clinical Infectious Diseases. 2015

Immunity to natural rotavirus infection

• Anderson EJ, et al. “Rotavirus Infection in Adults.” The Lancet Infectious Diseases. 2004