Review of the Food-borne Zoonoses Research ... - ARCHIVE: Defra

young-stock. The effect of control measures, that targeted at various combinations of the
above risk factors and potential environmental reservoirs, was assessed in a randomised
controlled trial. A visual effect of a package consisting of clean and dry near-environment
and animals, avoiding introduction into groups and overall farm-level biosecurity
measures was identified, albeit the cost of implementation of the whole package was
much higher than the economic benefits to society.
OZ0145
OZ0145 provided additional value of the data collected under OZ0138 by identifying and
describing compliance and motivation factors present during the trial and adjusting for
these in the statistical models, yielding evidence that dry bedding, closed rearing groups,
closed herd policy and no contact with other cattle reduced VTEC in a group of cattle
over a period of 4.5 months. These results were disseminated via presentations aimed at
farmers, private veterinarians, articles in trade and scientific journals and presentations at
international conferences. The data was also used to examine excretion patterns, coexistence
and risk factors of VTEC, Campylobacter and Coccidia in young cattle for a
period of 6-8 months and revealed that Campylobacter increased the risk of VTEC
excretion, changing water in troughs reduced both Campylobacter and Coccidia and that
large herds were more likely to harbor all three pathogens. The prevalence over time was
also used to validate a stochastic model of transmission of VTEC within a beef herd,
which was produced to test potential future interventions. The farmers from the trial were
revisited and interviewed about control of zoonses present on their farms, their concerns
and their attitudes and constraints in applying control measures and their opinions of
responsibility and financing safe cattle products. The main constraints were lack of
knowledge, lack of belief in self-efficacy and no financial flexibility within the enterprise,
but in general the attitudes towards improving food safety were very positive. The project
will proceed to review risk factors and control strategies for several zoonotic agents
important for cattle aged 3-24 months of age to work towards a combined zoonotic
control package.
Review Summary
Project OZ0138 produced valuable data on the prevalence of E. coli O157 in cattle in
England and Wales. At the time of commissioning, the incidence of human VTEC O157
disease had been increasing and this research provided essential data on the
epidemiology of this organism in the UK. Results also complemented the work carried
out by the Scottish Agricultural College, showing colonisation of calves occurs ‗postrumen‘
for E. coli O157. Risk factors for cattle herds becoming infected with E. coli O157
were identified; while this indicated that some measures could be taken to reduce the risk
of cattle excreting E. coli O157, elimination of the organism is not currently possible.
However, the work contributed to the clean livestock at slaughter policy.
Interventions identified in project OZ0138 were trialled in the follow-on project, OZ0145,
and the motivators for uptake of control measures by farmers assessed. The project
showed that changes to young-stock management, including keeping bedding dry and
avoiding introduction of new animals to established herds can reduce VTEC O157 on
cattle farms. Integration of measures to reduce risk of E. coli O157 infection with those to
reduce the risk from other pathogens may be more likely to be taken up by farmers than
a series of individual packages. This indicates that a more holistic approach to
communication may be more appropriate than the current approach of communicating
one aspect of food production at a time.
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