During the recent investigation of the outbreak of Salmonella Saintpaul, CDC often mentioned that the overall “outbreak investigation is complex and difficult.” This complexity and difficulty extends to the hundreds of outbreaks that never make national headlines as local public health officials trace outbreaks to specific venues and food items. CDC assists local public health officials to investigate about 100 multi-state clusters or confirmed foodborne outbreaks each year; many of which never lead to a specific implicated food item; approximately 10 that are particularly large, complex or extended become formal Epi-AID investigations. The use of a fingerprinting system for disease agents has greatly enhanced our ability to detect outbreaks but increases the effort to review suspicious clusters. For example, we now get over 60,000 patterns added to the database each year. This week, CDC’s OutbreakNet Team is evaluating 35 different clusters to determine their significance. This includes an investigation of an outbreak of Salmonella Poona with the same fingerprint pattern.