Containing Norovirus Lisa Ritchie Nurse Consultant Infection Control

Norovirus: Thought to be commonest cause of acute gastroenteritis in humans Usual incubation period is hours Usually manifests with acute onset of vomiting and non-bloody diarrhoea with abdominal cramps and nausea Less frequent clinical manifestations include fever, headache and myalgia Symptoms usually last between hours Infection is generally self-limiting thought that up to 30% of infections may be asymptomatic.

ICT alerted and ward closed Exporting outbreak to multiple wards Decontaminate Ward(s) Cross transmission occurs People with norovirus symptoms admitted to the ward Immediate isolation & containment? No cross transmission Outbreak prevented Early outbreak signs recognised? Able to apply and sustain Norovirus Control Measures? New cases cease Ward(s) reopened ICT (eventually) alerted Yes No Yes No Inability to gain control Continuous exporting of outbreak Inability of systems to cope No

Literature review Levels of Evidence and Category of Recommendation SIGN levels of evidence 3: Non-analytic studies, e.g. case reports, case series 4: Expert opinion SIGN grades of recommendation D Evidence level 3 or 4; or Extrapolated evidence from Studies Rated as 2+ (SIGN. Key to evidence statements and grades of recommendations. SIGN 50: a guideline developer’s handbook. Edinburgh: SIGN; Available at: (accessed: 18/10/2010). Reproduced with permission)

Control measures for Norovirus: Wards should be closed to new admissions The ward should remain closed until it has been terminally cleaned to the satisfaction of the ward manager and ICT and, –There have been no new cases of possible norovirus for 48 hours and, –There has been no vomiting or diarrhoea for a full 48 hours which is considered to be caused by norovirus. Patients should be cohorted Staff should be cohorted Non-essential staff should be excluded from affected wards

Control measures for Norovirus: Do not use alcohol based hand rub alone for routine decontamination of hands when there is an outbreak of gastro-intestinal infection. Decontaminate hands by washing with liquid soap and warm water followed by alcohol based hand rub. A surgical face mask may be worn to minimise the risk of splash contamination and inhalation of norovirus and subsequent ingestion. 1000ppm available chlorine should be used for environmental cleaning to inactivate norovirus Carpets and soft furnishings should be steam cleaned or cleaned with water and detergent after an outbreak of norovirus Bed/window curtains should be removed and cleaned

Control measures for Norovirus: Visitors should for their own safety be advised: To reduce the number of visits whilst the outbreak lasts. To wash hands on entry and exit to the ward. Not to visit if they themselves are suffering from an infection and until they are 48 hours symptom free. That children should not visit the ward during an outbreak. That they should not visit other people in the ward or other wards.

Challenges: 4 hours on trolley in A&E No designated ward / area available Control measures Change in symptom and behaviour of Norovirus from season to season

Norovirus season has begun – media warnings Early experiences Lessons learned Changing experiences?