Cases were recorded as ‘confirmed’ if they had gastroenteritis,
had eaten at the incriminated restaurant between 17 July and 7
August 2003, and had S. Typhimurium isolated from their
stools. Cases were recorded as ‘probable’ if they had gastroenteritis
and had eaten at the incriminated restaurant during
the same period in the company of a confirmed case, but no
stool culture was performed.