Financial analysis of East Coast fever control strategies in traditionally managed Sanga cattle in Central Province of Zambia

Economics of East Coast fever: a literature review

East Coast fever (ECF) is a cattle disease caused by a protozoan parasite called Theileria parva (T. parva). Theileria parva is transmitted among cattle by ticks. It is endemic in parts of central, eastern, and southern Africa and imposes an economic burden through illness and death of approximately a half of a billion U.S. dollars annually. This paper reviews existing science on the economics of ECF. We utilize a conceptual model that defines primary categories of economic costs due to ECF and use it to organize a synthesis of the literature on aggregate and micro level direct costs of the disease and the costs and benefits related to various ECF management strategies. We then identify knowledge gaps to motivate for future research.

Application of system dynamics and participatory spatial group model building in animal health: A case study of East Coast Fever interventions in Lundazi and Monze districts of Zambia

East Coast Fever (ECF) is the most economically important production disease among traditional beef cattle farmers in Zambia. Despite the disease control efforts by the government, donors, and farmers, ECF cases are increasing. Why does ECF oscillate over time? Can alternative approaches such as systems thinking contribute solutions to the complex ECF problem, avoid unintended consequences, and achieve sustainable results? To answer these research questions and inform the design and implementation of ECF interventions, we qualitatively investigated the influence of dynamic socio-economic, cultural, and ecological factors. We used system dynamics modelling to specify these dynamics qualitatively, and an innovative participatory framework called spatial group model building (SGMB). SGMB uses participatory geographical information system (GIS) concepts and techniques to capture the role of spatial phenomenon in the context of complex systems, allowing stakeholders to identify spatial phenomenon directly on physical maps and integrate such information in model development. Our SGMB process convened focus groups of beef value chain stakeholders in two distinct production systems. The focus groups helped to jointly construct a series of interrelated system dynamics models that described ECF in a broader systems context. Thus, a complementary objective of this study was to demonstrate the applicability of system dynamics modelling and SGMB in animal health. The SGMB process revealed policy leverage points in the beef cattle value chain that could be targeted to improve ECF control. For example, policies that develop sustainable and stable cattle markets and improve household income availability may have positive feedback effects on investment in animal health. The results obtained from a SGMB process also demonstrated that a “one-size-fits-all” approach may not be equally effective in policing ECF in different agro-ecological zones due to the complex interactions of socio-ecological context with important, and often ignored, spatial patterns.

Epidemiology of East Coast fever (Theileria parva infection) in Kenya: past, present and the future

In this article, we review the epidemiology of East Coast fever (ECF), a tick-borne infection of cattle, in Kenya. The major factors associated with epidemiology of ECF include the agro-ecological zone (AEZ), livestock production system (LPS) and both animal breed and age. These factors appear to influence the epidemiology of ECF through structured gradients. We further show that the gradients are dynamically shaped by socio-demographic and environmental processes. For a vector-borne disease whose transmission depends on environmental characteristics that influence vector dynamics, a change in the environment implies a change in the epidemiology of the disease. The review recommends that future ECF epidemiological studies should account for these factors and the dynamic interactions between them. In Kenya, ECF control has previously relied predominantly on tick control using acaricides and chemotherapy while ECF immunization is steadily being disseminated. We highlight the contribution of ECF epidemiology and economics in the design of production system and/or geographical area-specific integrated control strategies based on both the dynamic epidemiological risk of the disease and economic impacts of control strategies. In all production systems (except marginal areas), economic analyses demonstrate that integrated control in which ECF immunization is always an important component, can play an important role in the overall control of the disease. Indeed, Kenya has recently approved ECF immunization in all production systems (except in marginal areas). If the infrastructure of the vaccine production and distribution can be heightened, large ECF endemic areas are expected to be endemically stable and the disease controlled. Finally, the review points the way for future research by identifying scenario analyses as a critical methodology on which to base future investigations on how both dynamic livestock management systems and patterns of land use influence the dynamics and complexity of ECF epidemiology and the implications for control.

Assessing the impact of East Coast Fever immunisation by the infection and treatment method in Tanzanian pastoralist systems

A field trial was carried out in a Maasai homestead to assess the impact of East Coast Fever (ECF) immunisation by the infection and treatment method (ITM) with the Muguga Cocktail on the occurrence of this disease in Tanzanian pastoralist systems. These data were further used in partial budgeting and decision analysis to evaluate and compare the value of the control strategy. Overall, ITM was shown to be a cost-effective control option. While one ECF case was registered in the immunised group, 24 cases occurred amongst non-immunised calves. A significant negative association between immunisation and ECF cases occurrence was observed (p≤0.001). ECF mortality rate was also lower in the immunised group. However, as anti-theilerial treatment was given to all diseased calves, no significant negative association between immunisation and ECF mortality was found. Both groups showed an overall similar immunological pattern with high and increasing percentages of seropositive calves throughout the study. This, combined with the temporal distribution of cases in the non-immunised group, suggested the establishment of endemic stability. Furthermore, the economic analysis showed that ITM generated a profit estimated to be 7250 TZS (1 USD=1300 TZS) per vaccinated calf, and demonstrated that it was a better control measure than natural infection and subsequent treatment.

Perception of cattle farmers of the efficacy of east coast fever immunization in Southern Zambia

A study using a structured questionnaire was conducted to assess the perception of cattle farmers of the efficacy of East Coast fever (ECF) immunization in southern Zambia. One hundred and seventy-nine farmers from five districts in southern Zambia were interviewed. The majority of farmers (85%) perceived ECF immunization as being very effective and about half of them (51.4%) preferred immunization to other ECF control strategies. The study showed that the number of calves immunized was strongly associated with the farmer's perception of the benefits of immunization. There was no association between the number of calves immunized and the number of veterinary assistants in a given district or their transport situation. Overall mortality in ECF-immunized calves from various causes stood at 4.2%. Based on farmers' reports, the majority of these deaths seemed to have been caused by anaplasmosis, another tick-borne disease, and might have resulted from relaxation of tick control after ECF immunization. The reasons identified by farmers for not immunizing their animals included failure by immunizing teams to reach certain areas, not having calves of immunization age, and lack of money. These findings provide valuable information on how livestock farmers perceive and adopt new animal disease control strategies and the information could be useful in their planning and implementation.