Connecting divergent worlds : Social and ecological factors influence tick-borne diseases in tropical drylands

Chepkwony, Richard Kiprotich


Tick-borne diseases (TBDs) such as East Coast fever, anaplasmosis and babesiosis and their resultant mortalities are major constraints to livestock production, wildlife conservation and human health with ramifications on livelihoods, especially in the tropical drylands. The control of TBDs in the tropical drylands include pasture spelling, keeping livestock perceived to be TBDs resistant and the use of chemical acaricides. Although the use of acaricides is still the most dominant control practice for the control of TBDs, this approach is constrained by the least understood interactive effects of ecological and social factors. For instance, during the wet season, rainfall is considered a prominent ecological factor that directly or indirectly influences vegetation, host availability and movement, and land-use activities. Social factors include weak information sharing and governance issues in disease management. These uncertainties mirror the struggles that livestock farmers face and the results of this study may be applied to improve the management of TBDs in tropical areas. It is assumed that enhanced information sharing by actors through the adoption and scaling up of innovative technologies such as mobile phones and citizen science could be leveraged for information sharing to address TBDs in the tropical drylands. The interactions between the ecological and social factors influencing TBDs represent a socio-ecological system (SES) problem addressed in this thesis. It is critical to understand how various factors interact to promote the spread of or to impede effective control TBDs in tropical drylands. In this thesis, the central focus is to investigate the social and ecological factors and their interaction effects on TBDs, and what could be the potential of mobile phones in reporting TBDs in tropical drylands?

This thesis draws on literature review and empirical data (qualitative and quantitative), applying SES modelling, to explore the interactive effects of the ecological and social factors exacerbating the spread of, or impeding the control practices of TBDs in Laikipia County, Kenya. As a theoretical framework, SES modelling recognises that peoples’ behaviour, the environment or the context in which they occur are embedded within larger interactive and overlapping ecological and social systems.

In Chapter 2, I analyzed the existing long-term data on rainfall and cattle mortalities from Olpejeta Conservancy in Laikipia County to determine the associations between rainfall-induced mortalities in Boran cattle. The results suggested that East Coast fever (ECF) and anaplasmosis were negatively correlated with rainfall, with a lag of 2 and 6 months for ECF and anaplasmosis, respectively. However, Babesiosis could not be correlated to rainfall. This is a new finding identifying the associations between ecological factors and TBDs-induced cattle mortalities.

In Chapter 3, I sampled ticks in wildlife and livestock in both pastoral and commercial ranching areas. As expected, wild herbivores (zebras, rhinos and elephants) had significantly higher tick loads than livestock. The results suggested that animals with poor body conditions had significantly higher tick loads than those with good body conditions, irrespective of the management system. Cattle in transhumant pastoral areas had significantly higher tick loads than those in intensively managed commercial ranches. This study is among the few studies that highlight the importance of considering ecological and social factors influencing TBDs in tropical drylands.

In Chapter 4, I conducted a study aimed at identifying the unknown social factors and their interaction effects and the historical contexts constraining the control of TBDs, including the relationships between farmers, extension officials and actors involved in TBDs management. The results suggested that the control of TBDs in Kenya is a product of the pastoral communities and western-ideologic based veterinary thought with two different logics, sometimes converging but often at odds over fundamental socio-economic conditions perpetuated by the previous colonial regime and the pastoralist logic of herd immunity. Here, the analysis of the interplay of historical context, practices and interactions between TBDs actors reveals the power relations, tensions and contradictions emerging from an attempt to impose a western model of zoonotic disease management in the landscape with different biological outcomes. This new result gives insight into the biopolitics involved in zoonotic diseases management, opening up a discussion on how the dominant socio-political systems could be challenged and transformed into a more resilient one in the face of compounding uncertainties.

In chapter 5, I conducted a study aimed at (i) identifying issues of concern that complicates TBDs management in Kenya, including (ii) the assumption that lack of information by actors complicates the control of TBDs. Furthermore, I sought to clearly understand why and how farmers use mobile phones to address local issues of concern, including TBDs, and (iii) reflect on the implications of these results on the development of citizen science-based platforms for information sharing on TBDs. The results suggested that mobile phones are widely used for various socioeconomic activities: to communicate with family members and friends and to access information on pressing issues of concern such as human (in)security, human-wildlife conflicts and the occurrences of notifiable zoonotic diseases, forming issue-based networks of communication. I concluded that the design of mobile phone-based platforms and citizen science for information sharing on TBDs management should consider the motivation and the underlying socio-political factors influencing the information-sharing culture in an area. Together with chapter 4, the results of this study underscore the importance of diverse information dissemination channels, including farmer-to-farmer communication, radio or television talk shows which could be leveraged in the remote rural areas in the tropical areas characterised by poor communication infrastructure to enhance information sharing for effective control of TBDs.

Together, the four studies in this thesis strongly suggest that in tropical drylands (1) the major issues of concern which cut across the spread and control of TBDs in Laikipia County, Kenya, are related to the interactive effects of ecological and social factors, and (2) these cross-cutting issues impinge on people’s trust, power relations, communication and information sharing, extending into cases of human-wildlife conflicts and human insecurity. Specifically, the control of TBDs is compounded by the interaction effects of environmental (rainfall), biological (age, species, body condition of hosts) and social factors (management systems, socio-economic inequalities between farmers, historical contexts, relationships of TBD actors), representing a socio-ecological system. The results of this study also suggested that to successfully address TBDs, we require a clear understanding of its complexity, rather than reducing it to its most simplistic parts. This study highlights a profound need of addressing TBDs at all levels of the social and political structure while addressing the factors contributing to poor implementation of the control practices of TBDs. This study also highlights that to improve information sharing by actors, then we also need a clear understanding of the trust and relationship issues between farmers, extensionists, acaricide stockists and policy-makers at all levels. Furthermore, this study highlights the importance of co-design of projects including the development and scaling up of innovations such as digital platforms for information sharing to enhance TBDs management and agricultural production.