GLOBAL - Last week, the results were presented of a study of a number of potential animal and human health concerns in slaughter pigs in the UK, writes Jackie Linden.
An effort involving co-operation of many UK partners, researchers looked at the prevalence of a number of potential public and animal health risks in UK pigs at slaughter.
This study was initiated by Defra and co-funded with the Veterinary Medicines Directorate, the Food Standards Agency, Public Health England and the British Pig Executive.
Research was co-ordinated and led by the Animal Health and Veterinary Laboratories Agency (AHVLA). Samples were collected by the Food Standards Agency and the Northern Ireland Department of Agriculture and Rural Development and laboratory examination was undertaken at several AHVLA Regional Laboratories, as well as Public Health England and Public Health Wales.
A total of 645 pig carcasses were randomly selected and sampled between January and May 2013 at 14 slaughterhouses that together process 80 per cent of all finishing pigs slaughtered in the UK.
The multi-agency multi-funded project provided important data on numerous potential public and animal health risks, including the first UK-wide prevalence estimates for Toxoplasma, Hepatitis E virus, Porcine Reproductive and Respiratory Syndrome virus and Extended Spectrum Beta-Lactamase (ESBL) E. coli in slaughter pigs.
There was a consistently lower prevalence of bacteria found on carcasses than in the animal, giving evidence of the effectiveness of the dressing procedures in the abattoir to limit the contamination of pig carcasses and thereby control the risk of exposure of consumers to potentially harmful microorganisms.
For Salmonella, the prevalence was 31 per cent based on the caecal swabs and under 10 per cent for the carcass swabs, explained Tanya Cheney of AHVLA.
Toxoplasma is a protozoan that is widely prevalent in humans, pigs and other animal worldwide, she explained. Symptoms are usually mild. Seroprevalence was seven per cent.
Richard Tedder of Public Health England reported that prevalence of the hepatitis E virus was 93 per cent of the samples, with under six per cent showing current infections. The types of virus carried in pigs and people are quite separate, according to the virus "family tree".
Yersiniosis is a zoonotic gastrointestinal disease. Ms Cheney reported that it was found in 33 per cent of pig tonsil samples, and the prevalence in the carcass swab samples at under two per cent.
For PRRS virus, the seroprevalence was 58 per cent, with eight per cent having PRRSv RNA-positive tonsils. This method does not distinguish between pigs that have been vaccinated and those which have developed immunity as the result of infection. The virus does not infect humans.
Chris Teale of AHVLA reported the results of tests on antimicrobial resistance in Campylobacter. Overall, 153 Campylobacter coli isolates were tested for their in vitro susceptibility to seven antimicrobials.
The greatest levels of resistance were observed against tetracyclines (78 per cent) and streptomycin (66 per cent). There was also a moderate level of resistance against erythromycin (27 per cent), nalidixic acid (17 per cent) and ciprofloxacin (12 per cent). No resistance was observed against either chloramphenicol or gentamicin, which are rarely used in pigs and never for mass administration.
For ESBL E. coli, Dr Teale reported an overall prevalence of 23 per cent.
Also in the news in the last week are reports of Porcine Epidemic Diarrhoea (PED) in Japan and Colombia as well in the US and Canada.
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