Human campylobacteriosis and contaminated poultry
Submitting Institution
University of AberdeenUnit of Assessment
Clinical MedicineSummary Impact Type
PoliticalResearch Subject Area(s)
Medical and Health Sciences: Medical Microbiology
Summary of the impact
In one of the world's largest molecular epidemiological studies of its
kind, researchers at the University of Aberdeen identified retail chicken
as the single largest source of Campylobacter food poisoning in
Scotland. Informed by this research, a joint working group with membership
from industry and government was created to identify and put into place
interventions to reduce Campylobacter in chickens. In addition,
the evidence from Aberdeen was used by the European Food Safety Authority
and the New Zealand Food Safety Authority to develop their own integrated
approaches to protect the public from this food poisoning pathogen.
Therefore this has resulted in impact relating to: health and welfare,
commerce and public services and international policies.
Underpinning research
Campylobacter is the most common cause of food poisoning in the
UK. Symptoms include diarrhoea, abdominal pain, fever and vomiting, and
infection can prove fatal for very young children, the elderly and
immunosuppressed individuals. The Food Standards Agency (FSA) says Campylobacter
was estimated to be responsible for more than 460,000 cases of food
poisoning in England and Wales in 2012, resulting in more than 22,000
hospitalisations and 110 deaths. Campylobacter accounts for a
third of the cost of the burden of foodborne illness in England and Wales,
estimated at more than £583 million in 2008, since when infection
prevalence has increased by some 30%.
Since 2001, researchers at the University of Aberdeen have investigated
sources of human campylobacteriosis food poisoning. This work has been led
by Ken Forbes, Reader in the Department of Medical Microbiology
(1989-present), Norval Strachan, Professor of Physics (1998-present) and
Iain Ogden, Research Fellow (1996-2012). In conjunction with the Food
Standards Agency, they have led a substantial research programme involving
industrial collaborators and collaborators at Oxford and Glasgow
Universities.
Campylobacter bacteria live commensally in the gastrointestinal
tracts of a wide range of animals and birds and so initial research
focussed on identifying the sources of Campylobacter infection in
humans (2001-2009). This involved a combination of statistical data
analysis, public surveys and laboratory work. In the Aberdeen
laboratories, multi-locus sequence typing was used to characterise
isolates recovered from samples allowing researchers to reliably type
different Campylobacter strains. This multidisciplinary process
established that Campylobacter infection in humans was linked with
Campylobacter contaminated poultry [1,2] and that exposure can
influence a person's subsequent susceptibility to infection [3].
This research also showed that, especially in a rural environment,
non-poultry sources of infection (i.e. from ruminants or wild birds) are
also important [4,5]. Furthermore, high resolution molecular epidemiology
was able to link trends in human Campylobacter infection with the
changes in the population structure of Campylobacter found in
retail chicken [6]. Also, although virtually all campylobacteriosis cases
are believed to be sporadic (not recognisably linked) this epidemiological
research identified evidence of a common source of infection in one-sixth
of cases, even across considerable distances. This suggests that the UK's
extensive food distribution networks may be playing an important role in
the dissemination of contaminated chicken.
References to the research
[1] Sheppard SK, Dallas JF, Strachan NJC, Macrae M, McCarthy ND, Falush
D, Ogden ID, Maiden MCJ, Forbes KJ. (2009). Campylobacter
Genotyping to Determine the Source of Human Infection. Clinical
Infectious Diseases, 48:1072-1078.
Definitive research that led to this impact. Cites=75 by Aug 2013
[2] Strachan NJC, Forbes KJ. (2010). The growing UK epidemic of human
campylobacteriosis. Lancet 376:665-667.
Cites= 8 by Aug 2013
[3] Forbes KJ, Gormley JF, Dallas O, Labovitiadi M, Macrae RJ, Owen J,
Richardson J, Strachan NJC, Cowden JM, Ogden ID, Mcguigan CC. (2009). Campylobacter:
immunity and co-infection following a large outbreak in a farming
community. Journal of Clinical Microbiology 47:111-116. Human
exposure to Campylobacter. Cites=16 by Aug 2013
[4] Rotariu O, Dallas JD, Ogden ID, Macrae M, Sheppard SK, Maiden MCJ,
Gormley FJ, Forbes KJ, Strachan NJC. (2009). Spatiotemporal homogeneity of
Campylobacter subtypes from cattle and sheep across NE and SW
Scotland. Applied and Environmental Microbiology 75:6275-6281. Non-poultry
Campylobacter epidemiology. Cites=11 by Aug 2013
[5] Strachan NJC, Gormley FJ, Rotariu O, Ogden ID, Miller G, Dunn GM,
Sheppard SK, Dallas JF, Reid TMS, Howie H, Maiden MCJ, Forbes KJ. (2009).
Attribution of Campylobacter infections in northeast Scotland to specific
sources using multi-locus sequence typing (MLST). Journal of Infectious
Diseases 199:1205-1208.
Human Campylobacter epidemiology. Cites=36 by Aug 2013
[6] Gormley FJ, Macrae M, Forbes KJ, Ogden ID, Dallas JF, Strachan NJC.
(2008). Has retail chicken played a role in the decline of human
campylobacteriosis? Applied and Environmental Microbiology
74:383-390.
Campylobacter epidemiology in poultry and humans. Cites=48 by Aug 2013
Funding supporting the work:
[i] Pennington TH, Ogden ID, Forbes KJ (2001-02) "Identification of the
source of the Campylobacter summer surge: an MLST study". £38,363
from Chief Scientist Office, Scotland.
[ii] PhD studentship (2001-2005) "Understanding the causes of human
campylobacteriosis" £33,900 from the University of Aberdeen Faculty of
Science and Engineering.
[iii] Cowden J, Smith-Palmer A, Strachan N, Ogden I (2005-08) "Collection
and analysis of household water samples of participants from Campylobacter
case control study". £172,143 from Food Standards Agency.
[iv] Forbes KJ, Ogden ID, Strachan N, Fenlon D, Maiden M (2005-2008) "The
Molecular Epidemiology of Scottish Campylobacter Isolates from
Human Cases of Infection using Multilocus Sequence Typing". £832,246 from
Food Standards Agency.
[v] PhD studentship (2005-2008) "Elucidating the epidemic fall of human
campylobacteriosis". £39,000 from the University of Aberdeen plus £10,000
from Food Standards Agency.
[vi] Reid S, Innocent G, Strachan N, Rotariu O, Forbes KJ, Ogden ID
(2006-2007) "Factors associated with geographic and temporal variation in
campylobacteriosis in humans". £321,196 from Food Standards Agency.
[vii] PhD studentship (2008-2011) "Campylobacteriosis: Elucidating the
Disease Burden, Risk Perception and Costs to Rural Communities and their
Families". £55,000 from Rural Economy & Land Use programme Tied
Studentship award, ESRC/BBSRC.
[viii] Forbes KJ, Ogden ID, Strachan N, Maiden M (2010-12 and 2013-15)
"Employing Source Attribution and Molecular Epidemiology to measure the
impact of interventions on human campylobacteriosis in Scotland". £297,236
and £754,875 from the Food Standards Agency.
Details of the impact
The Aberdeen report investigating the key sources of Campylobacter
infection in Scotland was the first study in the world to do so on a
national scale. It provided the Food Standards Agency (FSA) Scotland with
clear evidence that broiler chickens were the single most significant
source of Campylobacter food poisoning [a,b]. The report was
published by the FSA Scotland (2009) on its website [c], and the Aberdeen
researchers were invited to present their findings at an FSA key
stakeholder event held a month later which was attended by some 100
stakeholders in NHS microbiology and public health, public analysts,
Defra, FSA, Health Protection Scotland (HPS), the National Farmers' Union
(NFU), the then Scottish Agriculture College (SAC), the Scottish Food
Advisory Committee (SFAC), and the Scottish Government Health Department.
As a direct result of the Aberdeen findings [c,d], the FSA recommended
intervention strategies should be targeted to the broiler food chain, and
the FSA's Strategy for 2010-2015 [e] and its Foodborne Disease Strategy
(2010-2012) [e] were developed. The important role of contamination in
undercooked chicken liver pate, eg [3], in many outbreaks has been
identified in FSA health warnings.
One month after the FSA report was published, a Joint Working Group on Campylobacter
(JWGC) was established as a joint industry and government initiative [f]
with an aim to identify interventions that could reduce Campylobacter
in chicken. Membership includes the British Poultry Council (BPC), the
National Farmers' Union (NFU) the British Retail Consortium (BRC), the FSA
and Defra. Drawing on the researchers' identification of the role the UK's
food distribution network has played in the dissemination of contaminated
chicken, an Action Plan with a strategy for overseeing on-farm, transport,
processing, retail, consumer and catering sector trials and interventions,
as well as surveillance and monitoring, was developed. An industry target
to reduce Campylobacter in UK produced retail chicken from 27% to
10% by 2015 was set.
In terms of public health, the JWGC estimate that reaching their target
of 10% reduction in Campylobacter loads in broilers by 2015 could
mean a reduction in Campylobacter food poisoning of up to 30% —
about 170,000 cases per year. In 2009, the Aberdeen team provided the
European Food Safety Authority (EFSA) BIOHAZ panel with evidence of the
extent to which meat derived from broiler chickens contributes to human
campylobacteriosis. The panel recommended the establishment of active
surveillance of campylobacteriosis in all member states — including a
representative collection of isolates from humans and putative reservoirs
in all member states for genotyping and storage [g,h]. Following on from
their assessment the EFSA is expected to set maximum permitted Campylobacter
loads in chicken within the EU next year.
During October 2009 a member of the Aberdeen research team work shadowed
and presented at a workshop at the New Zealand Food Safety Authority on
the use of molecular modelling techniques to identify different strains of
Campylobacter in order to gain a better understanding of the
sources of New Zealand's own epidemic and to support appropriate
intervention strategies. Resulting interventions led to lower incidences
of infection in New Zealand broiler chickens and reduced incidences of
human campylobacteriosis and of Guillain-Barré syndrome, which is
associated with prior campylobacteriosis. This was followed up in
September 2013 when two delegates from the New Zealand Ministry for
Primary Industries (industry regulators) discussed recent action and
trends in both countries with Forbes and Strachan.
Aberdeen research insights have been used to raise awareness of food
poisoning by Campylobacter among health practitioners and the
general public through articles such as that in The Lancet [2].
Members of the team have are also been regularly quoted in the press (e.g.
The Sunday Times, May 2009) and asked to contribute expertise to
programmes such as BBC Radio 4's Face the Facts (January 2013)
[i,j]. In September 2013 the Aberdeen research team hosted the biannual
international Campylobacter conference (www.chro-2013.org/)
at which 450 delegates from 40 countries discussed disease burden and
global concerns.
Therefore the claimed impacts as listed by REF include: disease
prevention has been enhanced by research; decisions by a health service
or regulatory authority have been informed by research; public awareness
of a health risk has been raised. Impacts on commerce have been that
industry (including overseas industry) has invested in research and
development and that strategy, operations or management practices of a
business have changed. Impacts on public policy and services have been
that policy debate has been stimulated and moved forward by research
evidence; policy decisions have been informed by research evidence.
Impacts on production have been that decisions by regulatory authorities
have been influenced by research. International policy development has
been influenced by research.
Sources to corroborate the impact
Examples of Policy Impact: UK
[a] Background to the Campylobacter Risk Management Programme and
Joint Working Group with links to the policy paper on the development of
the target for reducing Campylobacter in chicken production.
www.food.gov.uk/safereating/microbiology/campylobacterevidenceprogramme/
[b] Food Standards Agency, BBSRC, DEFRA, UK Research and Innovation
Strategy for Campylobacter in the Food Chain (2010).
www.food.gov.uk/multimedia/pdfs/campylobacterstrategy.pdf
[c] The Molecular Epidemiology of Scottish Campylobacter Isolates
from Human Cases of Infection using Multilocus Sequence Typing. CaMPS -Campylobacter
MLST Project in Scotland Food Standards Agency (2009). {report by Aberdeen
team}
www.food.gov.uk/news/newsarchive/2009/may/campylobacterinfection
[d] Private water supplies as a risk factor for Campylobacter
infection in Aberdeen City and Aberdeenshire. {Report by Aberdeen team et
al}
www.food.gov.uk/science/research/devolvedadmins/scotlandresearch/scotlandresearch/ScotlandProjectList/s14023_24/
[e] Food Standards Agency, The Foodborne Disease Strategy for
2010-2015. University of Aberdeen research is cited, though not
named, on p14 (the proportion of human disease attributable to retail
chicken sources).
www.food.gov.uk/multimedia/pdfs/fds2015.pdf;
www.food.gov.uk/aboutus/publications/busreps/strategicplan/
[f] Joint Government and Industry target to reduce Campylobacter
in UK produced chicken by 2015. The research from the University of
Aberdeen is cited as references #15, #17 on page 7 in www.food.gov.uk/multimedia/pdfs/campytarget.pdf;
www.food.gov.uk/safereating/microbiology/campylobacterevidenceprogramme/wgcampy
Examples of Policy Impact: European Union
[g] European Food Safety Authority views on Campylobacter.
www.efsa.europa.eu/en/topics/topic/campylobacter.htm
[h] BIOHAZ panel report in 2010 on "Quantification of the risk posed by
broiler meat to human campylobacteriosis in the EU.
www.efsa.europa.eu/en/efsajournal/pub/1437.htm
Media References
[i] Sunday Times, 31 May 2009 Most chickens carry food bug.
[j] BBC Radio 4 "Face the Facts" 16 January 2013 "Campylobacter —
the silent epidemic".
www.bbc.co.uk/programmes/b01ptzmf
People who have provided testimonials
Director, Food Standards Agency Scotland, St. Magnus House, 25 Guild
Street, Aberdeen, AB11 6NJ.
Director, WHO Centre for Risk Assessment of Pathogens in Food and Water,
RIVM, Netherlands. (EFSA BIOHAZ Panel member).