As the number of school children in East and West Flanders infected by a salmonella outbreak rises to 313, the cause remains unknown, investigators said. The infection has been traced by the Federal Food Safety Agency (FFSA) to a single catering company in West Flanders, but it remains unclear what the origin of the bacteria was. In the beginning, a shipment of lasagne was suspected, as portions were delivered to all of the schools originally concerned.
Now FFSA has carried out tests on stool samples from employees of the company, with negative results, which suggests the contamination did not originate within the plant after all. Salmonella is transmitted via intestinal bacteria, as a result for example of poor hygiene after using the toilet.
Samples taken from foodstuffs and equipment in the plant were also negative. FFSA investigators are now considering an external source of the infection, principally the lettuce which children were also served. However they are faced with a problem: given the time that has passed, there are no longer any viable samples of the lettuce available for testing.
The catering company will be allowed to open again for business on Monday, but will not deliver to the 44 schools affected, while tests and later disinfecting work are carried out on their own kitchens.