A long with diagnostic testing and treatment in managing foodborne infectious diseases, outbreak investigation is the most critical and diffi cult task. There is always an overabundance of factors that have to be taken into account when investigating an outbreak. The possible sources of food contamination covers a huge range that starts at the farm and leads to the table. There are many handlers of food and sources of contamination that can occur during all the stages of food preparation (from slaughter to serving). We also have to take into consideration location of the outbreak, epidemiology of the contaminant and the area in which the outbreak occurred and the virulence of the pathogen, among other things. The essential questions that are asked during an outbreak are: where did it originate, what is transmitting it, who is becoming infected, why did it occur, and how do we control and manage it.