Purpose: In December 2010, the Codex Committee on Food Hygiene (CCFH) requested that FAO and WHO provide the Committee with “guidance on the parasite-commodity combinations of particular concern.” FAO and WHO initiated a series of activities to provide this guidance, culminating in an expert workshop in September 2012.
Methods: During a weeklong expert workshop, a multi-criteria decision analytic approach was developed and applied. Experts screened an initial list of 95 parasites down to 24 and identified food pathways for each. A tool was designed interactively with the experts to score the importance of each parasite-commodity combination along seven criteria, including disease prevalence, global spread, trends, severity, case-fatality ratio, trade relevance, and socio-economic impact. Each parasite was scored by groups of five along these criteria, with revisions following full-group discussions. Groups provided weights for combining criteria into scores, which were then computed, averaged across groups, and ranked.
Results: Experts ranked Taenia solium, Echinococcus granulosus, Echinococcus multilocaris, Toxoplasma gondii, and Cryptosporidium as the top five parasites from a global foodborne perspective, followed by Entamoeba histolytica, Trichinella spiralis, Opisthorchiidae, Ascaris, and Trypanosoma cruzi. Rankings were largely driven by public health impact over other criteria.
Significance: This multi-criteria ranking is the first of its kind for global foodborne parasites, and served as a useful, systematic, and open approach to providing policy guidance. The approach itself has broader applications, as it could be adapted for regional or national use, or expanded to other infectious diseases.