Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Baseline Sampling of Pig Zoonotic Diseases - OZ0150

A national control programme for Salmonella in pigs is likely to commence in 2013. The aim of this programme will be to protect public health by reducing the risk of foodborne disease due to Salmonella in consumers of pig meat and associated products. Prior to the start of the mandatory NCP, the AHVLA are proposing to undertake a monitoring programme for Salmonella in UK pigs at slaughter. A sample of 600 pigs will be randomly selected and representative of the UK pig slaughter population. The samples will be collected over a 4 month period, as such the survey will not account for any seasonal variations. Three different sample types, (rectal swab, carcase swab and caecum), will be used to determine the prevalence of Salmonella (this work is supported by Defra, FSA and BPEX).

The undertaking of an abattoir based survey presents a cost saving opportunity to collect samples for the detection of different organisms. It is therefore proposed to undertake testing of Toxoplasma, Hepatitis E, Yersinia, ESBL E. coli and AMR in Campylobacter. Blood, heart, tongue, tonsils and a carcass swab will additionally be collected, by staff working for FSA with assistance from the FBO. The samples will be taken, along the processing line from the same identified pig. Samples will be returned to AHVLA Bury for testing at Bury or for onwards processing at a different location.

In the recent ACMSF report on Toxoplasma it was noted that there is little data on Toxoplasma meat contamination in the UK and “further data on seroprevalence in farm animals would be useful in monitoring the effectiveness of control measures in animal husbandry and testing of a larger range of meat samples would be useful in identifying the main sources of risk. Further studies are therefore recommended to establish seroprevalence in UK livestock species”. Serum and a selection of tissue samples will be taken and sent to the Toxoplasma Reference Unit for testing (this work is supported by the FSA and BPEX).

There is recent evidence to suggest that pig faecal contamination of food stuff does occur in European pork food supply chains (Di Bartolo et al. 2012; Berto et al. 2012). Based on current knowledge and understanding it would appear unlikely that HEV, that is detected in pork food products and which has been associated with Hepatitis E in humans, is attributable solely to pig faecal contamination. Hepatitis E is a dose-dependant disease with patients that are exposed to higher doses of HEV often developing clinical symptoms whereas patients exposed to lower doses of the virus generally only have subclinical infections (Meng, 2010; Purcell & Emerson, 2001). A survey of serum samples will allow for an assessment of pigs that are viraemic at slaughter, where products subsequently entering the food chain can include infected blood, for example, muscle. Detection of HEV within serum sampled from pigs at slaughter age would provide evidence for the potential for muscle to contain virus. Serum samples will be collected and sent to Colindale, HPA for HEV testing.

Yersinia was identified in the recent EFSA opinion on meat inspection in pigs as a hazard and Member States are recomended to gather prevalence data in and on pigs at slaughter. Tonsils and carcase swabs will be taken and tested for Yersinia, this work is supported by FSA and BPEX. Under the relevant legislation (Directive 2003/99/EC and secondary legislation) EU Member States (MSs) are obliged to monitor and report the antimicrobial resistance of Campylobacter isolates recovered from poultry, pigs and cattle. Monitoring and reporting of antimicrobial resistance in E. coli is encouraged, but currently has no statutory basis (although that situation is currently under review). The testing of caecal samples for Campylobacter and AMR and ESBL E. coli will meet the requirements of the EU legislation – this former (Campylobacter) is supported by VMD and the latter (ESBL E. coli) by FSA.
The AHVLA will undertake a baseline survey of Salmonella, Toxoplasma, Hepatitis E, Yersinia, ESBL
E. coli, Campylobacter and AMR in UK pigs at slaughter

The AHVLA will support these aims with the following objectives:

1. To contribute to the planning and introduction of the monitoring programme for Salmonella, Toxoplasma, Hepatitis E, Yersinia, ESBL E. coli, Campylobacter and AMR in UK pigs at slaughter.

2. To help construct a sampling frame of pig carcasses and abattoirs in the UK based on information supplied by FSA.

3. To randomly allocate the samples of pig carcasses from the sampling frame for each abattoir participating in the survey.

4. To work with funders to design and produce a questionnaire to gather epidemiological data on each sampled slaughter pig.

5. To design and produce a form to accompany samples to the laboratory.

6. To develop sampling protocols for the survey and to provide information to FSA for use in training for samplers.

7. To make up the sampling kits and send to the abattoirs as required.

8. To culture samples for Salmonella, undertake serotyping and phage typing on a subset of Salmonella isolates for UK.

9. To send serum samples to the Toxoplasma Reference Unit in Swansea for testing for Toxoplasma. Tissue samples (heart and tongue) will also be sent with the serum samples (tissue type to be confirmed by FSA Operations).

10. To send EDTA plasma sample to the Health Protection Agency, Colindale for HEV testing.

11. To process and archive caecal samples for future HEV testing.

12. To undertake testing of Yersinia, ESBL E. coli, Campylobacter and AMR.

13. To develop a database to manage the survey and hold the survey data.

14. To enter the epidemiological and testing data onto the database and to follow up any missing data or other identified problems with the data.

15. To analyse the prevalence results for each disease/ organism and to produce a report on the findings of the baseline survey. (Toxoplasma results and HEV results to be sent to AHVLA by the Toxoplasma Reference Unit and HPA respectively for inclusion in the UK report).

16. To participate in meetings with Defra, FSA, BPEX, HPA and VMD as required to update them on progress with the project.
Project Documents
• EVID4 - Final project report : OZ0150 EVID4 Final Report   (217k)
• EVID4 - Final project report : OZ0150 EVID4 Final Report SECTION 8   (1136k)
Time-Scale and Cost
From: 2013

To: 2014

Cost: £371,527
Contractor / Funded Organisations
A H V L A (Animal Health and Veterinary Laboratories Agency - AHVLA)
Animal Health              
Fields of Study
Animal Health