New Zealand microbiological risk ranking of imported fruits and vegetables

This article presents the outcomes of a scientific review and microbiological risk ranking of fresh, frozen, processed, and preserved fruit and vegetables imported into New Zealand. The study was undertaken by New Zealand Food Safety to help in the prioritisation of imported food safety issues for risk management action and ensure that regulatory resources are appropriately focused on food products that represent the highest public health risk.

Risk ranking, also sometimes called comparative risk assessment, is a methodology where the most significant risks associated with specific hazards and foods are identified and characterised, and then compared. The output is a list of pathogen-food combinations ranked according to their relative level of risks, from highest to lowest.

This study involved the development of a New Zealand risk ranking model based on two multicriteria analysis models developed separately by the United States Food and Drug Administration and the European Food Safety Authority (BIOHAZ Panel) for similar risk ranking applications. The New Zealand model uses nine criteria that have been adapted to New Zealand data and circumstances.

The eight top ranking pathogen-produce combinations identified using the New Zealand model were pathogenic E. coli in lettuce, spinach and other leafy greens, Salmonella spp. in lettuce, other leafy greens, tomatoes, melons, and other Cucurbitaceae (e.g. cucumbers, gourds, squashes, pumpkins). Produce categories were also ranked based on overall risk from various pathogens associated with each produce category. The top ranked produce categories, in decreasing order of rank, were: other leafy greens, pods, legumes and grains, tropical fruits, berries, herbs and spinach.

The risk ranking lists provide a starting point and basis for risk management considerations and prioritisation of resources. They will need to be regularly updated to ensure they remain relevant by incorporating the latest epidemiological, hazard, and import volume data. Updates should also consider the availability of new modelling tools and analytical methods for emerging or less common pathogens.