Journal of Food Science vol:79 issue:4 pages:R421-R427
The significance of fresh vegetable consumption on human nutrition and health is well recognised. Human infections with Escherichia coli O157:H7 and Salmonella enterica linked to fresh vegetable consumption have become a serious public health problem inflicting a heavy economic burden. The use of contaminated livestock waste (manure, waste water, abattoir waste) in crop production is believed to be one of the principal routes of fresh vegetable contamination with E. coli O157:H7 and S. enterica at pre-harvest stage since both ruminant and non-ruminant livestock are known carriers of E. coli O157:H7 and S. enterica in the environment. A number of challenge-testing studies have examined the fate of E. coli O157:H7 and S. enterica in the agricultural environment with the view of designing strategies for controlling vegetable contamination pre-harvest. In this review we examined the mathematical modelling approaches that have been used to study the behaviour of E. coli O157:H7 and S. enterica in the manure, manure-amended soil, and in manure-amended-soil-plant ecosystem during cultivation of fresh vegetable crops. We focused on how the models have been applied to fit survivor curves, predict survival and assess the risk of vegetable contamination pre-harvest. The inadequacies of the current modelling approaches are discussed and suggestions for improvements to enhance the applicability of the models as decision tools to control E. coli O157:H7 and S. enterica contamination of fresh vegetables during primary production are presented.