IMPACT: Standardising molecular detection methods to IMprove risk assessment capacity for foodborne protozoan PArasites, using Cryptosporidium in ready-to-eat salad as a model

Abstract

Protozoan parasites such as Cryptosporidium spp., Giardia duodenalis and Toxoplasma gondii are important causes of human and animal disease. Between them, these three parasites were estimated in 2010 to cause about 47 million cases of illness (incidence 185 cases per 100,000 population) in Europe. Outbreaks are increasingly recognised and attributed to consumption of food; fresh produce and leafy greens in particular. To date, there is a lack of readily applicable standardised methods for testing food and feedstuffs, which could provide additional evidence in risk assessments and validating control points and interventions.

The aim of the IMPACT project was to increase the European-level capacity for risk assessment of foodborne protozoa using Cryptosporidium and ready-to-eat salad leaves as a model example.

A review of procedures for the detection of Cryptosporidium in fresh produce has led to the production of guidance for undertaking artificial contamination studies to verify and validate detection methods, and as well as to the selection of a real-time PCR to help improve detection. These were achieved through literature review, a market survey of oocyst producers and suppliers, questionnaires, e-meetings and a workshop of experts. A SOP for Cryptosporidium molecular detection of oocysts in leafy greens by real-time PCR was developed and evaluated in two laboratories and rolled out to four other recipient laboratories for optimisation. Video tutorials were compiled to facilitate SOP implementation. Validation of the SOP through a ring trial involved five partners from the consortium and seven further European laboratories.

To facilitate a harmonised approach for data collection in future risk assessments, the findings of the project and final SOP were disseminated primarily using the network of the National Reference Laboratories in Europe and the EFSA focal points, and an extended network previously built during the COST Action Euro-FBP, as well as the OHEJP project network.