The infective dose is uncertain, although it is generally considered to be high for healthy individuals, with food contamination rates of more than 1,000 cells/g being required. Due to the length of the incubation period, it can be difficult to determine the numbers of bacteria in foods at the time of consumption. An outbreak associated with frankfurters in the USA in 1998 is thought to have been caused by product containing less than 0.3 cells/g, although it is suspected that the strain involved may have been unusually virulent.khăn giấp
đang được dịch, vui lòng đợi..
