ETHICOBOTS (Ethiopia Control of Bovine Tuberculosis Strategies)

Ethiopia is the second most populous sub-Saharan African country with a rapidly growing population. It is a least-developed, predominantly agrarian country struggling to emerge from extreme poverty, through an ambitious national growth and transformation plan, to achieve middle income status by 2025. Livestock contributes to a high proportion of national income and is one of the pillars to economic development. Traditional extensive farming systems with the less productive local Zebu cattle are being supplemented and replaced with intensive farming of imported Holstein-Friesian and their cross breeds at a rapid rate driven by high demand for dairy and meat products of a rapidly growing urban population. Although bovine tuberculosis (bTB) is endemic in Ethiopia, the prevalence is low among the local Zebu cattle because of their relative resistance. Expansion of dairy farms around major urban centres has however created hotspots of TB infected exotic cattle. With no legal requirement to test and cull infected cattle in Ethiopia, unlike in developed countries, the potential for rapid spread of bTB across the cattle trade routes through amplification by the dairy farms in peri-urban areas is a real emerging danger.
We propose to develop control strategies for bTB in Ethiopia based on investigation and analysis of the epidemiology of the disease and its determinants through a series of interlinked social and biological science studies, encompassing the emerging livestock system, livelihood of affected farmers and available tools for bTB control. We will determine disease prevalence among dairy cattle in different areas, capture cattle trading and exchange mechanisms, study risk management and mitigation practices for households and document how prevailing social, cultural and economic factors impact them. We will quantify the burden of bTB among exposed intensive farm and abattoir workers and determine how illness and health is managed in poor families. Local perceptions of infection and disease transmission, coping mechanisms and gender roles in order will help explain consumption practices. In turn, these may enhance disease risk and impact poverty and wellbeing amongst an expanding high risk group. We will compare disease susceptibility among the local and Holstein cattle and evaluate the degree of protection given by BCG vaccination to cross-breed cattle. Based on the multidisciplinary information gathered by these investigations, we will assess the feasibility of various bTB control strategies such as vaccination, control of animal movements and health education within the Ethiopian context. We will determine factors that affect implementation such as cost-efficiency, social and cultural acceptability and practicality. This will be coordinated with targeted capacity building of Ethiopian researchers and institutions to enhance multidisciplinary scientific capabilities for sustainable local research for the longer term.
The results will provide practical and effective bTB control strategies, which when applied, will significantly reduce the high rate of bTB and its zoonotic transfer in the expanding dairy sector; minimize trading of bTB infected dairy cattle to protect the national zebu herd and the livelihood of poor farmers; and reduce the risk of zoonosis in high risk populations. The current proposal builds on previous experience of a successful collaboration with the Ethiopian Government on bTB to focus on an emerging rapid change in the nature of livestock systems in this developing country, dairy farms, that impact on the livelihoods and health of poor people. The project will be carried out with the active participation of the relevant government units and local communities in the field to maximize the likelihood of implementation of results into policy and practice. The main expected outcome is reduced impact of a zoonotic disease on poor people and their livestock in a least developed country.

Ethiopia has the largest livestock population in Africa including 53 million cattle. A rapidly growing human population (85 million people) and high rate of urbanization give increased challenges on farmers and government to meet the demand for food. Meat is supplied to urban centres through trading of zebu cattle. In contrast, milk production of zebus is poor compared to exotic breeds such as Holstein or their crosses with zebus; zebus alone cannot meet the increased demand for milk and dairy products. An emerging dairy sector in Ethiopia aiming to increase milk supply is however more vulnerable to diseases thriving in intensive husbandry systems. Epidemiological surveys on bovine TB (bTB) in Ethiopian livestock have mapped out relatively low prevalence (0-9%) in the domestic zebu cattle in rural Ethiopia, reared under extensive conditions, while studies of exotic or cross bred cattle in the peri-urban intensive dairy farms in central Ethiopia recorded over 30% tuberculin prevalence. Thus, the impact of such high bTB prevalence could be significant on both animal productivity and public health, especially on high-risk populations exposed to cattle. Expansion of the dairy farm sector and the current centrifugal trade of high value cattle from an area of high bTB prevalence can result in new hotspots of bTB in emerging dairy farm regions around peripheral urban centres. Such trading may also highly affect agro-pastoralists of the Ethiopian highlands, increasing the risk of zoonosis and transmission to their zebu herds. The main objective of this proposal is to develop control strategies for bTB in Ethiopia that could significantly reduce the high rate of bTB and its zoonotic transfer in the expanding dairy sector. Experimental, social and economic information gathered in a multi-disciplinary research programme built on six work-packages will be used to assess feasibility, acceptance and cost-efficiency of various bTB control strategies, including cattle vaccination.

This programme will deliver a greater scientific and socio-political base for the control of zoonotic mycobacterial infections spreading from the emerging dairy industry in Ethiopia. The dairy industry is a major emerging livestock system in Ethiopia, concentrated around growing urban centres. This industry depends on 'exotic', imported Holstein-Friesian (HF) cattle and their crosses with local Zebu cattle. The importation and breeding of these HF cattle is now associated with a high prevalence of Mycobacterium bovis, the cause of bovine tuberculosis (bTB), which can reach 40% or more in infected herds. It was this prevalence of infection in the national herd in Britain that was associated with milk-borne transmission of M. bovis to humans with an annual zoonotic death toll of ~2,500, prior to the introduction of pasteurisation. We hypothesise that the poor workers in this industry and their families are at particular risk of zoonotic exposure and transmission.

Although the traditional Zebu industry is not heavily infected with M. bovis, the increasing cross breeding of Zebu animals with HF cattle runs the risk of the infection spreading into more extensive, lower value traditional farms, typically managed in smallholdings. In common with most countries in sub-Saharan Africa, there are no control programmes for bTB. Furthermore, given that 90% or more of dairy products are sold direct to consumers, unpasteurised, there is a risk, as the dairy industry emerges further in peri-urban areas, of widespread zoonotic transmission of M. bovis in here - and also if any significant spread to the traditional husbandry systems occurs.

This project aims to deliver an innovative programme of development of applied and socially and economically acceptable controls of bTB. With our focus on integrated, cross-disciplinary approaches, we will identify innovative interventions to protect and benefit the poor. This proposal has been put together with a clear focus on the long-term impact of the research results. The programme, which involves senior scientists from both Ethiopian and UK government research institutes, will feed directly into policy making in both countries, as well as to the international agencies that we are connected to. This work is of direct future relevance for other emerging dairy industries in the developing world, especially in sub-Saharan Africa, as well as indirectly for the UK industry, where cattle vaccination is actively being pursued.

Stakeholder workshops are planned early in the programme to engage with government, veterinary, medical, industry and farming stakeholders, to ensure that key issues are considered. In addition to a comprehensive capacity building programme for the Ethiopian partners, our training workshops and educational programmes will also be focused on the farming and high risk cohorts identified in the work. With research sites in the key dairy farm regions in Ethiopia known to be affected by bTB, we will have a strong and representative regional coverage. We will also build out from these regions to ensure actual coverage across the whole country in all relevant groups. We will also engage with relevant international agencies (eg OIE).

Through our interaction with individual farmers, farm-workers, community health workers and vets, we will develop targeted information about bTB with the aim of changing attitudes and practices relating to animal husbandry, consumption practices, and health seeking behaviour, in order to reduce the zoonotic impact on the health and economic burden of low-income farm workers and their families.

Taken together, the overall impact of the outcomes of the research will be to improve bTB control in Ethiopia and thus lead to significantly better human and animal health that will eventually translate itself into a significant input to accelerated economic development in Ethiopia and in other regions where the work may be of future relevance.