Topic: Enterohaemorrhagic E.coli (EHEC)
Description
E. coli are bacteria which are present in large numbers in the intestines of humans and animals. Most of these bacteria are not harmful. However, some strains, such as Enterohaemorrhagic E.coli (EHEC), produce a toxin which can cause a range of diseases in humans and may lead to serious complications in the bowel and kidney. Infected dairy and beef cattle are the main reservoir of infection of EHEC. Meat can be contaminated during slaughter and processing, particularly if minced. Unpasteurised milk, contaminated raw vegetables and contaminated water are also potential sources of infection.
Symptoms
Acute diarrhoea is the first symptom and can begin somewhere between two to 10 days but usually three to four days after eating the bacteria. This is followed by stomach cramps and bloody diarrhoea, with or without fever. Vomiting may also occur.
Transmission
The infection is mainly spread through people eating contaminated food. It can spread from person-to-person, particularly in institutional settings and where toilet/hand hygiene is inadequate. Accordingly, sufferers and close household contacts should consult a doctor before returning to work or school. Adults are generally infectious for one week or less but one third of children who are ill with the bacteria remain infectious for around three weeks.
Treatment
Treatment for complications such as dehydration and kidney failure may require hospitalisation, sometimes in intensive care. As a rule, antibiotics should not be used.
Health Outcome
About 10% of EHEC cases go on to develop a condition called Haemolytic Uraemic Syndrome (HUS). It tends to occur within seven days after the start of diarrhoea and is characterised by kidney failure associated with anaemia.
Prevention
Cook minced meat (eg. hamburgers) thoroughly until the juices run clear and there are no pink areas inside. Do not serve unpasteurised milk and its products to vulnerable people. Wash raw fruit and vegetables thoroughly before eating.
Always wash your hands after visiting the toilet, before and after handling food and before eating. Thorough hand washing with soap and water is the key to preventing the spread of this infection. Good hygiene practices are necessary when suspected or diagnosed cases of this infection are being cared for. The sick room, toilet and kitchen are high risk areas. Surfaces in these areas should be cleaned regularly with detergent and hot water.
Certain groups pose a higher risk to spreading infection:
- food handlers in the home, in institutions or in industry, especially those handling raw or uncooked foods
- carers of vulnerable people eg. health care personnel and nursery staff
- children under five years who attend nurseries or infant schools
- people who have difficulties in practising good personal hygiene.
Help and Assistance
For further information, please contact your local doctor, community health centre or nearest Population Health Unit.
Footnotes
Heymann, D., ed. 2004. Control of Communicable Diseases Manual, 18th edition. Washington, DC: American Public Health Association, pp 160-164.
National Health and Medical Research Council, 2003. The Australian Immunisation Handbook (8th Ed.) Canberra: National Capital Printing.
Other Resources
Queensland Health Food Safety Matters website
Last Updated: 12th October, 2009
Date Valid to: 30th June, 2010
