Unseasonal Increase in Norovirus Activity
- Maintain a high index of suspicion for Norovirus - assume all vomitus is infectious
- When two or more people in the same building/area/group develop vomiting within a day or so, it is likely to be norovirus
- Clean and decontaminate soiled areas immediately
Strict attention to routine hygiene/precautions and implementation of heightened cleaning/disinfection during outbreaks
- Exclude ill staff from work until 48 hours after the last episode of vomiting/diarrhoea
- Cohort ill patients to prevent further transmission
- Advise facilities to involve IPC colleagues at the earliest stage
Background
The HPSC have identified a period of moderately increased norovirus activity that has the potential to impact acute and residential facilities. This period of heightened activity could continue for some weeks. A similar increase in Noroviral illness has been seen in the UK, in some European countries and in the USA.
Clinical
Norovirus usually presents with sudden onset nausea and vomiting (often projectile), concurrent watery diarrhoea, and abdominal cramps. Low grade fever, headache, myalgia, and chills are commonly reported. Although generally mild, the elderly and immunocompromised are at increased risk of severe illness and dehydration.
When two or more people in the same building/area/group develop vomiting within a day or so, there is a high likelihood that it is norovirus
Duration of illness tends to be between one and three days. Patients should not return to work/school for 48 hours after resolution of all symptoms. Patients may continue to shed virus for some days, so careful hand hygiene is necessary on return to work/school.
In primary care, diagnosis of norovirus is primarily clinical; the characteristic nature of symptoms means that testing/virological confirmation is not required, except in community congregate settings. Further guidance is available in Infectious Intestinal Disease: Public Health & Clinical Guidance (page 12).
Diagnosis can be confirmed by faecal PCR analysis. Testing for norovirus is normally only performed in the context of a known/suspected outbreak (in an acute or residential health care setting, or in a community setting e.g. a hotel or school). This will then guide public health management.
During outbreaks, strict attention to routine hygiene/precautions and implementation of heightened cleaning/disinfection during outbreaks in facilities is necessary.
Noroviral illness is a notifiable disease. Notify your local department of public health.
Health Protection
View further guidance, including Interim Guidance Note on the Management of Norovirus in Residential Care Settings