A research team from Texas and Colorado in the USA has identified a number of risk factors governing the likelihood of pre-harvest E. coli contamination in spinach grown on farms in the two states.
The researchers analysed 955 spinach samples from 12 farms, finding E. coli present on 63 samples. Risk factors for contamination were found to include time since irrigation, farm workers personal hygiene and the previous use of the field where the spinach was grown.
The weather was an important factor in contamination and proximity to a poultry farm and irrigation using pond water were also found to increase the risk considerably. It is hoped that the findings can be used to help develop pre-harvest control strategies to reduce fresh produce contamination.
A report on the study is published in the journal Applied and Environmental Microbiology and a copy can be found here.