Qualitative Causal Loop Diagram: One Health Model Conceptualizing Brucellosis in Jordan

Abstract

Background: Brucellosis is a serious public health problem distributed worldwide. Jordan has one of the highest incidences of brucellosis globally, mostly caused by infection with Brucella melitensis, which is associated with small, ruminant animals such as sheep. Sheep are an important livestock species in Jordan where there is a high value is placed on keeping animals at home. The incidence of human brucellosis rapidly increased following the Syrian conflict, in association with the resettlement of displaced people. Methods: A systems thinking (ST) approach was applied to develop a model to explain the dynamics of brucellosis in Jordan. A causal loop diagram (CLD) was developed to visualize and conceptualize interactions and feedback between several factors involved in sheep husbandry, animal and human health, and livestock trading systems. The CLD was constructed using information from published literature, historical governmental reports, policy documents and media coverage regarding brucellosis in Jordan. Semi-structured, in-depth interviews with diverse stakeholders were conducted to elicit information on their understanding of critical factors associated with brucellosis. Results: The CLD demonstrated that brucellosis transmission in Jordan is driven by sheep husbandry practices like livestock movement/trading and the management of symptomatic animals (those suffering abortion). Five dimensions were identified to be associated with brucellosis transmission: human infection; consumers; traders and markets; and livestock infection and control. Conclusion: The development of a CLD to explain brucellosis transmission in Jordan provides a better understanding of and reveals the multi-sectoral nature of the problem. The need for a multi-sectoral approach for effective brucellosis management in Jordan is clear from the five dimensions identified.