Food safety and Streptococcus suis
Streptococcus suis is a bacterium commonly present in pigs in many parts of the world. In most cases it does not cause disease in pigs. People in direct contact with pigs or raw pig-products are at risk of infection but the small number of reported clinical cases in humans would suggest that the risk is very low.
Human infection is usually through direct contact with infected pigs or raw pig-products and is thought to occur through cuts or abrasions on the skin when handling infected pig material. Proper cooking (temperatures at or above 70º C in all parts of the product) kills this bacterium. Well cooked pork meat is safe but handling infected raw pig products, including those which are refrigerated or frozen, can be hazardous if good hygienic practices are not observed (see below).
The 2005 outbreak of Streptococcus suis in areas of Sichuan in China has raised concern about the risk associated with infected pork meat. In these areas, slaughtering and butchering of sick or dead pigs has been strictly prohibited. However, contact with infected pigs and raw pork from the affected areas could pose a risk of infection to farmers, slaughterers, butchers as well as to those processing or preparing the meat for consumption. The export of pork meat from the affected areas in Sichuan to Hong Kong was suspended on the 28 July 2005.
A group of international experts on Streptococcus suis convened by WHO reiterated that human infection is most likely to occur through cuts or abrasions on the skin. Although consumption of raw or undercooked pork may lead to disease, eating properly cooked pork is unlikely to represent an increased risk, even if the outbreak strain of Streptococcus suis involved is more dangerous.
Recommended good hygiene practices to avoid contracting Streptococcus suis:
- Do not slaughter sick animals
- Dead animals must not be used for food or feed and should be safely disposed to avoid contamination
- Wear protective clothing and ensure that all wounds are covered
- Keep the slaughtering area clean and separate from the food processing area
- Remove protective clothing and wash exposed body areas after slaughtering
During food preparation:
- Do not handle raw pig-products if you have wounds on your hands unless you cover all wounds by waterproof dressings or plastic gloves
- Keep the preparation area clean and wash your hands after handling
- Separate raw meat from cooked or ready-to-eat foods to avoid contamination
- Do not use the same chopping board or the same knife
- Do not handle both raw and cooked meat without washing your hands in between
- Do not place cooked meat back on the same surface it was on before cooking
- Cook thoroughly (temperatures at or above 70º C in all parts of the product)