Experts have gathered in Edinburgh today for the first of two meetings which aim to publicise the results of current surveillance and research programmes on harmful organisms in food.
The conference has been jointly organised by the Ministry of Agriculture, Fisheries and Food, in conjunction with the Scottish Executive for Rural Affairs, National Assembly for Wales Agriculture Department, the Department for Health and the newly formed Food Standards Agency.
The first of two such meetings concentrates on verocytotoxin-producing Escherichia coli O157 (VTEC O157), commonly known as E.coli O157.
Jim Scudamore, MAFF’s Chief Veterinary Officer, gave the conference’s introductory presentation.
Mr Scudamore said:
“Since first being identified as a cause of disease in humans in 1982, VTEC O157 has emerged as a significant public health problem. It can cause anything from mild diarrhoea to a life-threatening intestinal condition and haemolytic uraemic syndrome.
“Following much research into the organism, we are beginning to understand it a little better and the conference is an opportunity to consider all the new information together and let the public know what we have found out.
“We are looking at the ways in which humans can become infected and the risk factors associated with that, and we will consider the current recommendations for protecting public health.
“In the past few years it has been established that animals, particularly cattle, are a source of VTEC O157 for the human population, although the animals themselves rarely become ill. The results of the on-farm and abattoir studies will begin to fill in some of the gaps in our knowledge of the condition in animals.”
Research shows that although food remains an important means of human infection, the environment plays a greater role as a source of infection than previously thought.
Among the findings of the surveys are:
- The surveys confirm cattle as the main reservoir of VTEC O157. A Great Britain wide abattoir survey revealed a 4.7% incidence in cattle presented to slaughter and confirmed levels of VTEC 0157 in sheep (1.8%) and pigs (0.16%). In on-farm surveys of cattle in England and Wales 4.7% showed levels of VTEC 0157, whereas in Scotland 8.6 per cent of Scottish beef cattle between 12 and 30 months old showed levels of VTEC 0157.
- The apparent overall difference between England and Wales and Scotland is due to the fact that the Scottish survey looked at a narrow sample (beef cattle between 12 and 30 months) while the survey in England and Wales looked at cattle of all ages. When the data for cattle of a similar age is compared in both studies the figures are very similar.
- Generally speaking the number of individual animals excreting VTEC O157 is low. However a substantial percentage of herds contain at least one infected animal (at least 44% of dairy herds in England and Wales have at least one infected animal).
- Great Britain is not unusual in the level of VTEC O157 faecal carriage in food animals: faecal carriage is similar to levels recorded elsewhere in the world.
- Excretion of VTEC O157 is seasonal.
- Case control studies have shown that a high proportion of human cases had been exposed to environmental factors such as gardens, contact with farms, farm animals or farmland contaminated by infected farm animals, water supply failure or paddling in contaminated water.
- The young and the elderly are most at risk from contracting VTEC O157, with the young being most likely to become seriously ill.
- The infectious dose is very small.
Notes for Editors
1. This meeting is the first of two meetings being organised on behalf of the above departments. The second conference will be held on 7 December 2000 in London and will present final data on VTEC O157 along with data on other foodborne pathogens collected by the surveys.
2. Today’s meeting consisted of the following presentations:
Mr B A Synge – Epidemiological studies in cattle in Scotland;
Dr G Paiba – Prevalence in cattle, sheep and pigs at slaughter in GB and cattle on farms in England and Wales;
Dr S O’Brian – VTEC. How important is it?
Dr J Coia – Meat and dairy products surveillance in South East Scotland;
Prof W J Reilly – A case control study of sporadic cases in Scotland;
Dr G K Adak – A case control study of sporadic cases in England;
Dr G Pritchard – Open farm and other farm linked cases;
Dr P Stevenson – Overview of current research; and
Dr R L Salmon – Current recommendations to protect public health.
3. Abstracts from the above presentation are available from Tony Hitching, Zoonoses Division, Ministry of Agriculture Fisheries and Food, 1a Page Street, London, SW1P 4PQ. (Tel: 020 7904 6138 or by email: t.hitching@ maff.gsi.gov.uk).
4. FSA Scotland, Press officer John Booth ( Tel: 07767 172 165).