Download The Difficulties of Preventing and Controlling the Spread of Norovirus

The Difficulties of Preventing and
Controlling the Spread of Norovirus
‘The most common cause of infectious gastroenteritis’
(Pubic Health England, 2013)
Author: Rebecca Duncan, Student Environmental Health Officer at
Rhondda Cynon Taf County Borough Council
What is Norovirus?
Research Project- 2014
According to Public Health England (2013) norovirus is ‘the most common cause
of infectious gastroenteritis’ in England and Wales. Prystajecky et al (2011)
characterise Norovirus as vomiting, watery diarrhoea and fever. Although
sufferers normally recover within two to three days, it has a high infectious rate
with only 20 viral particles needed to infect someone. Transmission usually occurs
from eating infected food or drink, touching contaminated surfaces or, most
commonly, from close contact with someone infected (Centers for Disease,
Control and Prevention, 2013). The delayed symptoms, usually 24- 48 after initial
exposure can cause a problem for all ages, unlike other gastrointestinal illness. In
addition, symptoms usually last for 48 hours but it is still contagious for up to 48
hours after this point, despite sufferers feeling well.
In 2014, I carried out a Research project titled “What Influences the
Scale and Impact of Norovirus Outbreaks in Health Care Settings?”
A survey was disseminated via social media to the general public with
ten questions relating to norovirus and hygiene practices. A total of 100
responses were collected with an age range of 18-61.
From the results, a major difficulty found of controlling Norovirus is the
lack of education and awareness in a domestic setting. Those who work
in healthcare settings knew more about Norovirus and the correct
hygiene practices than those who didn’t. The following graph reflects
the fact that the majority of people do not know the correct enteric
precautions to prevent the spread of Norovirus. In particular, this
focuses on the 48 hour exclusion period necessary to prevent further
transmission to anyone else, most important if you are a healthcare
work or a food handler.
The Scale and Characteristics of Norovirus
The extent as to which norovirus affects the UK is uncertain. Public Health
England (2008) estimates that 600,000 to a million people are affected by
norovirus, in the UK every year. However, as Weinstein et al (2008) state, the
short-term symptoms and lack of clinically diagnosed cases, means that the
reported number of cases is likely to differ greatly from the true number. Reliance
is often placed on outbreaks that occur in healthcare settings for an estimate. In
comparison to other pathogens, norovirus outbreaks tend to be worse, as
norovirus is able to survive in the environment for up to four weeks, reflecting its
persistence and difficulty to control. In addition, as a virus it cannot be treated
with antibiotics like bacterial infections can. Furthermore, it has a much lower
infectious dose compared to other infections, rapidly increasing the spread of the
pathogen in the case of an outbreak.
Current Guidance
Due to the impact of norovirus, the British Infection Association (BIA) (2012)
produced a guidance document that aimed to help with management of
norovirus in healthcare settings with the necessary action to take; an example of
support that health care workers receive. Lopman et al (2004) estimate that
norovirus costs the NHS over £100 million a year. Due to the infectious
characteristics of Norovirus, sufferers need to be isolated to prevent transmission
to other patients who are immune-compromised and are likely to incur
complications if infected (Green, Bok, 2012). The guidance document lays down
procedures to minimise the scale of a norovirus outbreak such as isolation and
strict hygiene practices. in a leaflet provided by Public Health England (October,
2013) advice is given to sufferers not to visit the GP or hospital, in order to
prevent the spread of the infection, particularly as there is no treatment available.
In addition, the leaflet also advises people to wash their hands using soap and
water when preparing food and not to rely on alcohol gels; only effective against
bacteria.
However, it is difficult for people to follow such guidance as they may believe they
could be suffering with another illness instead of norovirus that is potentially
treatable. This is particularly as norovirus symptoms are similar to so many other
illnesses. Therefore, they may seek GP consultancy regardless of advice due to the
fact it ‘might not be norovirus’ and ‘it might be treatable’. By ignoring advice they
are increasing the risk of spreading Norovirus further.
Possible Way Forward?
An intervention not attempted yet, is the dissemination of new advice through
campaigns. Many norovirus cases go unreported as sufferers are told not to seek
medical advice . By offering different advice that asks sufferers to contact their
local doctor or a health line to report symptoms of norovirus, it allows both
accurate monitoring of cases and prevents sufferers from physically visiting their
GP or hospital. This way, we can improve the accuracy of scaling the spread. In
addition, a stool sample should be collected at the home. If the results are
positive, enteric precautions can be enforced to prevent transmission to others,
despite no treatment available for them.
Conclusion
The majority of people are aware of norovirus but do not carry out all
the recommended hygiene precautions. In particular they do not take
the necessary time off work to prevent transmission to others, posing a
greater risk to those who are immune-compromised and vulnerable.
Health workers are more likely to take off the necessary time from work
than food handlers and individuals from other work sectors, but this is
not sufficient to minimise the scale of a norovirus outbreak.
Interventions targeted at health workers, food handlers and those in
domestic premises will provide the greatest outcome, minimising the
transmission between individuals and thus minimising the scale and
impact of future norovirus outbreaks.
References
Public Health England. (2013). Norovirus. Available: http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1195733743985. Last accessed 29th Oct 2013.
Prystajecky N, Wong J, Auk B, Gamage B, Archer J, Fung J, Wong B, Isaac-Renton J,. (2011). Norovirus infections in health care settings. BC Medical Journal. 53 (3), 119
Centers for Disease, Control and Prevention (2013) Norovirus Transmission [Online] Available at: http://www.cdc.gov/norovirus/about/transmission.html Accessed on
14/04/2014
Public Health England (2008) Norovirus Toolkit A set of resources for staff in schools and nurseries [Online] Available at:
http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1227851390634 Accessed on: 15/03/2014
Weinstein R, Said M, Perl T, Sears C (2008) Gastrointestinal Flu: Norovirus in Health Care and Long-Term Care Facilities. Clinical Infectious Diseases. 47 (9), 1202-1208.
British Infection Association (2012) Guidelines for the management of norovirus outbreaks in acute and community health and social care settings [Online] Available at:
http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1317131639453 Accessed on: 15/03/2014
Lopman BA, Reacher MH, Vipond IB, Hill D, Perry C, Halladay T, Brown DW, Sarangi J (2004). Epidemiology and cost of nosocomial gastroenteritis, Avon, England, (20022003).Emerging Infectious Diseases. 10 (10),1827-34
Bok,K, Green,K. (2012). Norovirus Gastroenteritis in Immunocompromised Patients. The New England Journal of Medicine. 367 (1), 2126.
Public Health England. (October, 2013). Stop norovirus spreading this winter. Available: http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1317140036373. Last
accessed 29th Oct 2013.