UKHSA Weekly report for the 2025/26 season - Norovirus cases now 50% higher than average for this time of year

[Commonground]

Last Updated February 5, 2026
Excerpt:

Norovirus surveillance data between weeks 4 and 5 of 2026 (19 January to 1 February 2026)

In weeks 4 and 5:

• norovirus activity has remained high in recent weeks, particularly in adults aged 65 years and over
• overall, norovirus laboratory reports between weeks 4 and 5 of 2026 (19 January 2026 to 1 February 2026) were 50.6% higher than the 5-season average for the same 2-week period
• rotavirus activity between weeks 4 and 5 of 2026 was 18.0% lower than the 5-season average for the same 2-week period
• the number of norovirus outbreaks reported to the Hospital Norovirus Outbreak Reporting System (HNORS) since the start of the 2025/2026 season is 25.5% lower than the 5-season average
• during the 2025/2026 season to date, the majority (85.4%) of samples characterised were norovirus genogroup 2 (GII) and the most frequently detected genotypes, GII.4 (35.8%) and GII.17 (20.8%), have continued to co-circulate
• the timing of the typical seasonal increase and peak of norovirus activity varies from one season to the next. It is likely that multiple factors contributed to the high level of laboratory reports in recent weeks, including but not limited to co-circulation of multiple norovirus genotypes, weather conditions or changes in testing and reporting to national surveillance
• norovirus symptoms include nausea, vomiting and diarrhoea but can also include a high temperature, abdominal pain and aching limbs. Norovirus infections can cause dehydration, especially in vulnerable groups such as young children and older or immunocompromised people, so if you do get ill it is important to drink plenty of fluids during that time

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