Hazards Associated with Zoonotic enteric pathogens in Emerging Livestock meat pathways (HAZEL)
Zadoks, Sharp, Cleaveland
Meat from livestock (cattle, goats, sheep and poultry) is a key protein source for poor farmers, their families and communities. As countries develop, populations grow and move to urban areas and the nature of livestock systems has to change to keep up with consumer demand for meat. This presents an economic opportunity for poor farmers who may seek to produce meat for commercial markets but it also presents a potential threat to public health.
Centralization of slaughter and processing facilities and growth of distribution networks that serve wholesalers, retailers and consumers may have major implications for food-borne diseases because risks of infection and contamination are likely to increase with scaling-up of production systems and increasing complexity of supply chains.
Already, bacterial food-borne pathogens, including Salmonella and Campylobacter, have been described as the 'forgotten zoonoses' of Africa and changes in the meat supply chain may aggravate the problem. At the same time, improvements in policy, regulatory systems and technical capacity are potential tools to alleviate such problems.
Aims and Objectives
Our aim is to develop a robust understanding of how zoonotic enteric pathogens flow through the meat chain in Tanzania and to use this information to develop policies to improve food safety. We focus on Tanzania because the country has been identified as a hotspot for bacterial foodborne zoonoses and because its National Livestock Policy promotes intensification of livestock production systems to meet growing demand for meat.
Furthermore, our team can build on existing infrastructure and laboratory capacity and years of interdisciplinary research collaboration in the livestock dense areas of Arusha and Kilimanjaro. Thus, there is both a need and the capacity to conduct this research.
To achieve our aim, we will use an approach called modular process risk modelling (MPRM) to describe livestock meat pathways and hazards in these pathways. In the initial step, each stage of meat production from farm to retail is described by social and veterinary scientists. Local scale commercial production will be compared with wider markets to identify hazards that may emerge as meat production, processing and distribution is scaled up.
Once the meat supply chain is charted, microbiologic techniques are used to establish the presence and concentration of non-typhoidal Salmonella and Campylobacter at each step in chain.
By studying the genetic fingerprint of the bacteria, it is possible to track flow of bacteria from pre- to post-harvest. Comparison of DNA fingerprints of livestock and food isolates with those from bacterial isolates obtained from people with diarrhoea or other diseases will give an indication of the role of meat in human illness.
Whilst mapping emerging livestock meat pathways and their associated hazards, we will conduct a formal review of current food safety policies and regulations in Tanzania and assess how they are implemented. Knowledge of the strengths and weaknesses of existing policies, combined with opportunities and threats identified through analysis of the meat value chain and hazards in the livestock meat pathway will enable scientists and policy makers to develop new food safety policies.
Potential applications and benefits
Through its combination of social, biological and quantitative sciences and collaboration with policy makers, this project will contribute to improved food safety policy and reduction in food-borne exposure of people to non-typhoidal Salmonella and Campylobacter. This will provide economic and health benefits to producer and consumer communities in Tanzania.
In addition, improved product safety may help farmers to access new retail markets. Finally, the approach developed in this project can serve as a model for other diseases and countries where changes in livestock production systems may affect the availability and safety of our food.
First published: 18 August 2014