Author summary Brucellosis is a neglected, bacterial zoonotic disease that is caused by several species of the genus Brucella. Cross-species transmission of Brucella can occur in mixed or integrated farming systems. The disease poses serious public health implications and substantial economic losses particularly in low-income countries including South Sudan. This study was conducted to estimate the seroprevalence of brucellosis in pastoralists, their livestock as well identifying potential risk factors associated with Brucella infection. Knowledge of the seroprevalence of brucellosis and risk factors is a prerequisite towards planning an effective mitigation strategy of the disease. The study revealed high seroprevalence of brucellosis in cattle compared to goats, and the following risk factors were identified; prior history of abortion, age (old) and sex (female) significantly associated with Brucella infection. Surprisingly, sheep were found to be seronegative.

The authors have declared no competing interest.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ministry of Health, Research Ethics Review Board (MOH-RERB), Juba-South Sudan. Protocol No: RERB-P NO:13/14/02/2023 Institutional Review Board (IRB), Sokoine University of Agriculture Protocol no: DPRTC/R?186/16

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All datasets used or analyzed during the current study are available from the corresponding author upon request.