A method to prioritize the surveillance of chemicals in food commodities to access international market and its application to four countries in Sub-Saharan Africa.

The purpose of this study was to propose an approach to predict the distribution of chemicals in food in developing countries to assess consumer risk and access to the international market with a limited number of laboratory analyses. The first step consists of identifying the GEMS/Food Contaminants database and the chemical/food combination relevant for a particular country. The identification of critical chemical/food combination should be used to prioritize the analysis to be performed in a total diet study (TDS). The second step consists of modelling a distribution model based on the mean concentration generated from TDS associated with the variability observed in a larger dataset consisting of individual food contamination data from the GEMS food database. The simulated distributions may provide information regarding how to establish food safety standards and to assess the potential for accessing international market in the context of a value chain. This method is illustrated by case studies from the recent Regional TDS (RTDS) conducted in Sub Saharan Africa. We concluded that further work is needed to gain experience and to fully validate this approach. However, organized data sharing and developing harmonized methods for data analysis are key roles for international organizations, such as FAO, WHO, and WTO. Finally, it is important to remember that such a data-driven approach still requires significant investments in terms of human resources and analytical capacity.

Indirect estimation of porcine parvovirus maternal immunity decay in free-living wild boar (Sus scrofa) piglets by capture-recapture data.

Linear mixed regression and logspline density estimation were performed to estimate the survival curve and half life of passively acquired antibodies against porcine parvovirus (PPV) in 44 wild boar piglets captured in the Northern Apennines, Italy. One piglet had no detectable maternal antibodies at 2.5 months post partum and no antibodies were detected in any of the remaining piglets by 4 months of age. Fitted survival curves indicated that maternal antibodies were undetectable from 2.5 to 6 months of age, with a median value at 3 months and a low probability of persistent maternal antibodies after 4 months of age. The estimated half life was 23 days (95% confidence interval 22-26 days). The results agree with previous data for decay of maternally acquired antibodies against PPV in the domestic pig and indicate the value of capture-recapture analysis for the estimation of infection parameters in free-living animals.