In the previous section (Introduction), we have described the role of VBNC pathogens in public health and food safety, and even their involvement in many foodborne outbreaks; however, there is no evidence to show that VBNC pathogens directly caused the outbreak. We propose that one of the most possible reasons is the undetectability of VBNC cells. Recent findings showed that 20% of illnesses can be linked to known pathogens, but the remaining 80% are due to unspecified or unidentified agents (Nicolò and Guglielmino, 2012), indicating that VBNC pathogens may be ignored during most outbreaks due to undetectability. For example, in 2011 in Germany, there was a large outbreak caused by an E. coli O104:H4 strain expressing genes characteristic of enterohemorrhagic (EHEC) and enteroaggregative E. coli (EAEC), involving more than 3000 cases of bloody diarrhea and haemolytic uremic syndrome. Unfortunately, the local detection department failed to detect or isolate the E. coli O104:H4 strain from the source of contamination until a small amount of the pathogens were isolated from the patients (Aurass et al., 2011; Scheutz et al., 2011). We suggest that the main reason for the failure to isolate the E. coli O104:H4 outbreak strain is that this outbreak strain entered a non-culturable state. Aurass et al. (2011) also confirmed that the E. coli O104:H4 outbreak strain induced by copper ions or tap water of outbreak area entered the VBNC state and was resuscitated to become a potentially pathogenic bacterium by stress relief. This finding implies that VBNC E. coli O104:H4 may invade the human body through contaminated food, undergo resuscitation and thus lead to disease.