CFS announces results of targeted surveillance on Bacillus cereus and Clostridium perfringens in ready-to-eat food

The Centre for Food Safety (CFS) of the Food and Environmental Hygiene Department recently completed a targeted food surveillance project on Bacillus cereus and Clostridium perfringens in ready-to-eat food. Other than an unsatisfactory preserved bean curd sample announced earlier, test results of the remaining samples were all satisfactory.

A spokesman for the CFS said today (June 29), "A total of 180 ready-to-eat food samples were collected from over 150 retail outlets and food factories for testing of Bacillus cereus and Clostridium perfringens between February and April this year. The samples included dim sum, rice, noodles, pastries, soya products, stewed meat and meat sauce."

He added, "The CFS announced earlier that a bottled preserved bean curd sample contained Bacillus cereus at a level of 2.8 million per gram. According to the Microbiological Guidelines for Food, it is potentially injurious to health or unfit for human consumption if a gram of ready-to-eat food contains more than 100 000 of Bacillus cereus. The CFS has informed the importer concerned of the irregularity and instructed it to stop selling and recall the affected batch of the product."

Bacillus cereus is commonly found in the environment. It can form spores which are able to resist heat and survive cooking temperature. Bacillus cereus can produce different toxins causing two types of food poisoning. Emetic (causing vomiting) intoxication is caused by heat-stable toxins in food; another type of poisoning is diarrhoeal, which is caused by ingestion of a large amount of Bacillus cereus that can produce toxins in the intestine. As the production of preserved bean curd requires fermentation, Bacillus cereus would multiply when production is not hygienic or storage is not proper.

Meanwhile, food poisoning caused by Clostridium perfringens is usually associated with inadequately cooked foods or cooked foods that are cooled for prolonged period or stored under sub-optimal temperature. Foods prepared in bulk, especially cooked meat and poultry dishes, and those stored at room temperature with long cooling periods after cooking are at high risk. In food poisoning caused by the pathogen, common symptoms include vomiting, diarrhoea and abdominal pain, and maybe fever. Prolonged and severe symptoms are more likely to appear in the young, the elderly and those with a weaker immune system.

"The CFS received 70 and 69 food poisoning cases suspected to be related to Bacillus cereus and Clostridium perfringens respectively in the past three years. Therefore, the trade and the public should not take the risk lightly. The trade should observe the Good Hygienic Practices in each stage of production to ensure safe and proper processing of the food and to comply with the limits stipulated in the Microbiological Guidelines for Food, while the public should always maintain good personal and food hygiene," the spokesman said.

Ends/Monday, June 29, 2015