When to take action in food-borne disease outbreaks?

Identifying and controlling food-borne disease outbreaks (FBDO) remain important public health objectives. There is plenty of guidance on how to detect potential FBDO, e.g. epidemiologically or microbiologically. Likewise, the conduct of an outbreak investigation has long been codified in steps and adapted for FBDO. However, what is less clear is when to act, mainly when to implement appropriate control measures. This is particularly challenging when the causative agent has not yet been detected in the suspected food vehicle(s). The decision on when to act is complex and depends, besides the available evidence, also on other factors, such as the dynamic of the outbreak or the disease severity. No guidance exists for this decision. Notably, an FBDO investigation provides circumstantial evidence on the culprit, and its careful assessment entails an inherently subjective element. There is a need across sectors and countries in Europe for harmonising the view on what constitutes sufficient evidence for furthering investigations and timely taking action, depending on the outbreak situation. A common understanding and possibly a harmonised legislation are the basis for streamlining discussions and decisions during FBDO, thereby preventing the delay of implementing necessary control measures.