Case Study
Vomiting Larry: Visualising Contamination
The Client
Department of Health, Health and Safety Executive
The Problem
In order to help reduce the numbers of Norovirus outbreaks and
therefore improve public/workforce health and reduce the burden on
our economy, HSL developed a simulated vomiting system known as
vomiting Larry.
Norovirus (a winter vomiting disease) causes large outbreaks of
gastroenteritis worldwide. Outbreaks are most common in winter with
key symptoms of projectile (forced) vomiting and/or diarrhoea. It
is highly infectious and robust being resistant to many
disinfectants including the frequently used alcohol hand rubs. Many
industry sectors are affected by norovirus outbreaks, which impacts
substantially on our economy with a burden on the NHS alone of
around £100m per annum.
What We Did
This project was carried out by HSL's microbiology, virology and
workplace sampling team with help from other teams across the
Laboratory including exposure and control, immunology and
toxicology, Centre for Workplace Health, fluid dynamics,
epidemiology, visual presentation services and workshops. In order
to help reduce the burden of norovirus on our health and the
economy, HSL specialists:
- Developed a simulated vomiting system known as Vomiting Larry
to identify how much of the environment becomes contaminated when
an individual infected with Norovirus projectile vomits;
- Employed a commercially available realistic mannequin head
known as Airway Larry normally used as a training system for
medical students on which to practice procedures such as
laryngoscopies;
- Utilised a pneumatic ram and cylinder to form a piston pump
system allowing fluid to be forced out of the realistic mannequin
head;
- Used one of HSL's controlled atmosphere chambers (35
m3 facility) in which to conduct the vomiting
trials;
- Initially used water containing a fluorescent tracer as a vomit
substitute enabling researchers to identify how far small droplets
travelled using UV light, which would otherwise be invisible;
- Simulated projectile vomiting trials were also carried out
using a non-hazardous form of norovirus to identify how far and how
much live virus could be spread in the environment.
Other Findings:
- HSL found that in an episode of projectile vomiting 1 litre of
fluid could contaminate an area >7.8 m2
- Live virus could be found even in very small droplets of fluid
in numbers capable of causing infection
- The research identified the need for wider area cleaning and
decontamination of the environment during episodes of
vomiting/norovirus outbreaks
- The results of the study emphasised the need for wider area
cleaning and decontamination of the environment and were sent to a
norovirus working group who were preparing some new guidance on
norovirus
Outcome/Benefits
The research findings will now form part of a doctoral research
degree being undertaken by an HSL staff member, and has the
following benefits:
- Better opportunity to prevent Norovirus in future, through
improved knowledge of need for wider cleaning and
decontamination
- Raised profile of Norovirus through numerous media
opportunities - Vomiting Larry has received a large amount of media
interest including a part in a BBC documentary: 'Winter viruses and
how to beat them' presented by Michael Mosley (February 2013) and
short documentaries for Thomson Reuters and the Discovery
Channel.
See Vomiting
Larry
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