Shiga toxin-producing E. coli (STEC)
Escherichia coli (E. coli) are bacteria (germs) which are present in large numbers in the intestines of humans and animals. Most of these bacteria are not harmful. However, some types, such as Shiga toxin-producing E. coli (STEC), produce toxins which can cause illness in humans and may lead to serious complications in the bowel and kidney.
Symptoms of infection include abdominal pain and watery or bloody diarrhoea. Vomiting and fever may occur. Symptoms can begin anywhere between 2 to 10 days but usually 3 – 4 days after eating the bacteria. Infection may sometimes cause no or very mild symptoms.
Most people with mild illness recover without any specific treatment. Occasionally complications such as dehydration and kidney failure may require hospitalisation, sometimes in intensive care. The role of antibiotics in the management of STEC is unclear. Antibiotics are generally not recommended as they may increase the risk of haemolytic uraemic syndrome (see below).
The infection is mainly spread through people eating contaminated food. 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.
It can also spread from person to person if hands are not washed thoroughly after going to the toilet or changing nappies. People infected and their close household contacts should consult a doctor before returning to work or school. Adults are generally infectious for one week or less. One third of children can continue to pass on the infection for around three weeks. People can occasionally remain infectious for considerably longer.
Cook meat, including minced meat, e.g. hamburgers, thoroughly until the juices run clear and there are no pink areas inside. Do not serve unpasteurised milk and its products. Wash raw fruit and vegetables thoroughly before eating.
Always wash your hands after going to the toilet, changing nappies, 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 caring for suspected or diagnosed cases of this infection. The sick room, toilet and kitchen are high risk areas. Surfaces in these areas should be cleaned regularly with detergent and hot water.
To reduce the risk of spreading the disease to others, especially those who may develop serious illness, extra care needs to be taken for those in the following groups:
- food handlers in the home, in institutions or in industry, especially those handling raw or uncooked foods
- carers (e.g. nurses, doctors, childcare centre staff) of vulnerable people
- children under five years of age who attend childcare
- people who have difficulties in practising good personal hygiene.
In order to prevent the spread of infection, it is recommended that anyone with STEC infection not return to work/school/childcare or other settings until at least 24 hours after their diarrhoea has stopped. People in the higher risk groups listed above should not return until they have been shown to be clear of infection on stool specimens testing. In some circumstances people in close contact with someone with STEC infection may also need to be tested and to stay away from work/childcare etc.
Most people with STEC infection recover fully. Occasionally, people with this infection can go on to develop a condition called haemolytic uraemic syndrome (HUS). The risk of HUS following STEC infection has been estimated to be up to 8%. The elderly and children are at highest risk. HUS develops between 2 and 14 days after the onset of diarrhoea and is characterised by kidney failure and anaemia. It can sometimes be fatal.
For further information please contact your local doctor, community health centre, nearest public health unit, or the 13HEALTH information line (13 432584).
Heymann D (Ed). 2008. Control of Communicable Diseases Manual, 19th edition. Washington, DC: American Public Health Association, pp 181-186.
Ochoa TJ, Cleary TG. Epidemiology and spectrum of disease of Escherichia coli O157. Curr Opin Infect Dis 2003, 16:259-63.
Thorpe C. Shiga toxin-producing Escherichia coli infection. CID. 2004, 38:1298-303.
- Queensland Health Food Safety Matters website