The Zoonoses in Livestock in Kenya (ZooLinK) project is our newest activity. The goal of ZooLinK is to enable Kenya to develop an effective surveillance programme for zoonoses (meaning infectious diseases acquired through contact with animals or their products), which is, by design, integrated across both human and animal health sectors. To achieve this goal we will work in close collaboration with Kenyan government departments, working in western Kenya initially and using this as a model for a national programme.

The rationale for ZooLinK is that the presence and burden of zoonoses is greatly underestimated – as we know from our own research in the study region. In one recent but relatively small-scale study, we found 14 different zoonoses circulating in humans and their livestock. While estimating the current zoonotic disease burden is doubtless essential, another major objective is to understand how it will evolve in to the future.  In Kenya, and elsewhere in sub-Saharan Africa, far reaching changes are occurring in the agricultural sector, with major changes in livestock production systems in order to satisfy increased demand for livestock products. The most important changes are the commercialisation and intensification of what was previously subsistence farming, resulting in changes in trading patterns (e.g. the distances that livestock and their products are transported), and changes in favoured breeds and input supply systems. All of these affect the risk of zoonoses and other infectious diseases.

For example, our work has indicated that genes from exotic dairy cattle are ‘leaking’ into local cattle populations and altering susceptibilities to specific infections, and that changes in feed systems for improved livestock breeds may be introducing pressure on local bacterial populations to develop resistance. These issues are complex and understanding them well requires an interdisciplinary research approach. Importantly, disease surveillance is well established in some sectors in Kenya: Kenya already has a structure in place for veterinary surveillance for infectious diseases at livestock markets, slaughterhouses and butcheries and in the wider farming community. Surveillance for human disease also takes place in clinics and hospitals reporting infectious diseases in people. So the systems exist and are manned by trained staff. What is needed, and will be provided by ZooLinK, is increased awareness of zoonoses, better diagnostic support, better ways to record, share, analyse and interpret data, and closer integration between the human and animal health sectors. In order to convince potential funders of the value of a national programme, we need to provide evidence that an enhanced surveillance system can contribute to improving public health in a cost-effective manner. For this reason, during our project we will closely monitor our enhanced system’s performance and compare it to the current situation, identifying which activities do (or do not) provide good value for money.ZooLinK also provides a platform for Kenyan public and animal health workers to get hands-on training (e.g. in diagnostic methods or electronic data systems) and to become familiar with a ‘One Health‘ approach to surveillance. Training is coordinated by Kenyan partners and will generate a cadre of individuals with first-hand experience of this way of working – this should leave a very strong legacy in its own right. In addition to addressing these practical issues, ZooLinK is also providing a unique scientific evidence base which will help us to understand and anticipate changes in zoonotic disease burdens and to recommend effective interventions. This involves detailed study of economic, social, demographic, genetic, and epidemiological drivers and the way that these combine to produce an overall burden of disease and risk of disease outbreaks.

 

In this context, the unusually comprehensive nature of ZooLinK is a major advantage: there are obvious limitations to studying single diseases or drivers in isolation (e.g. changes that favour one disease may reduce the risk of another; or effects due to changes in one driver may be outweighed by changes in another). The high quality data being collected by ZooLinK, supported by state-of-the-art, diagnostics, genetics, and economic, statistical and mathematical modelling, will allow us to tackle such questions.