A neurological syndrome of small ruminants, known locally as ‘ormilo’, has been reported among pastoralist livestock keepers in Tanzania. This study was carried out in four affected pastoral communities to determine the prevalence and associated risk factors, characterise the clinical signs and investigate the aetiology of the syndrome. Questionnaires were administered at all households (n=480) within four study villages. Overall, 94 per cent of households reported at least one case in the previous 12 months. By village, the individual-level 12-month period prevalence ranged from 11 per cent to 34 per cent, equivalent to about 10,000 small ruminants across the four villages. Thirty-eight households were randomly selected for further investigation. Proprioceptive deficits and weakness were the most commonly observed clinical signs in affected animals. Brain and spinal cord cysts consistent with Taenia multiceps infection were detected in 32 (82 per cent) of 39 affected animals selected for postmortem examination. Feeding small ruminant brains to dogs was identified as an important risk factor for the syndrome, even in households that did not own dogs. This study confirms cerebral coenurosis as a major cause of small ruminant neurological disease in northern Tanzania and highlights the urgent need for further investigation to quantify the disease burden and to identify and implement control measures.
- Central Nervous System (cns)
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ECH and TKK contributed equally.
Contributors Conceptualisation of the study and acquisition of funding: ECH, TKK, WAdeG, FL, AD, OMN, JRC, SC and KJA. Field investigation: ECH, TKK, FL, OMN and KJA. Laboratory analysis: RWC, RMFdeJ and KJA. Data analysis and interpretation: ECH, WAdeG, SC and KJA. Manuscript writing: ECH, TKK, WAdeG, FL, AD, JRC, SC and KJA. All authors were involved in critical review and editing of the final manuscript.
Funding This research was supported by the Supporting Evidence Based Interventions project, University of Edinburgh (grant number R83537). Additional support was provided through the Zoonoses and Emerging Livestock Systems program (funded through BBSRC, DfID, ESRC, MRC, NERC and DSTL) (grant no: BB/L018926/1) and BBSRC (grant BB/R020027/1).
Competing interests None declared.
Ethics approval Research clearance for this study was granted by the Tanzania Commission for Science and Technology (no. 2018-48-NA-2005-141) and ethical clearance by the University of Glasgow School of Veterinary Medicine Ethics Committee (REF 43a/17).
Provenance and peer review Not commissioned; externally peer reviewed.
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