Containing Norovirus
Lisa Ritchie
Nurse Consultant Infection Control
Norovirus:
• Thought to be commonest cause of
acute gastroenteritis in humans
• Usual incubation period is 12-48
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
24-60 hours
• Infection is generally self-limiting
• thought that up to 30% of infections
may be asymptomatic.
People with norovirus
symptoms admitted to the ward
No cross
transmission
Yes
No
Immediate isolation &
containment?
No
Outbreak
prevented
Cross transmission occurs
Yes
Early outbreak signs
recognised?
ICT alerted
and ward closed
No
Exporting outbreak to multiple wards
ICT (eventually) alerted
No
Able to apply and sustain
Norovirus Control
Measures?
Yes
No
Continuous exporting
of outbreak
Inability to gain control
Inability of systems
to cope
New cases cease
Decontaminate
Ward(s)
Ward(s) reopened
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; 2008. Available at:
http://www.sign.ac.uk/guidelines/fulltext/50/annexb.html (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
Changing
experiences?
Norovirus
season has
begun –
media
warnings
Early
experiences
Lessons
learned