Taenia multiceps coenurosis in Tanzania: a major and under‐recognised livestock disease problem in pastoral communities

Abstract

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.

Safety, Immunogenicity and Antibody Persistence of Rift Valley Fever Virus Clone 13 Vaccine in Sheep, Goats and Cattle in Tanzania

“…Lack of significant difference related to body temperature, abortions or deaths between vaccinated and control groups in our study, supports the previous findings that the vaccine is safe and efficacious in domestic ruminants (18)(19)(20)(21). Although we did not confirm the causes of deaths, the clinical manifestations developed before death were consistent with a neurological disease of sheep and goats, known locally as "ormilo" (34). The disease has been reported as the leading animal disease of concern amongst the Maasai pastoralists in the study area (34).…”

“…Although we did not confirm the causes of deaths, the clinical manifestations developed before death were consistent with a neurological disease of sheep and goats, known locally as "ormilo" (34). The disease has been reported as the leading animal disease of concern amongst the Maasai pastoralists in the study area (34). Other common disease conditions in the study area to be considered in the differential diagnosis would include bacterial infections such as brucellosis (35).…”

The Sero-epidemiology of Neospora caninum in Cattle in Northern Tanzania

“…While we did not find a relationship with village-level dog ownership, it could be expected that free-ranging dogs infected with N. caninum could contaminate grazing areas across a wide area, thereby potentially exposing cattle from multiple households to oocysts shed by a single dog. This mechanism is thought to be important for the transmission of other dog-mediated pathogens to livestock in northern Tanzania (54).…”

Economic burden of livestock disease and drought in Northern Tanzania

“…This disease is caused by the larval form of the dog tapeworm, Taenia multiceps, which encysts in the brain and spinal cord of small ruminants (the reservoir hosts) typically causing a progressive neurological disease leading to death (Miran et al, 2015). Anecdotally, mortality rates associated with cerebral coernurosis, locally known as Ormilo, are increasing in northern Tanzania (Queenan et al, 2017;Hughes et al, 2019). Thirdly, there is some evidence that livestock holders in this region have been substituting away from cattle and buying small stock in response to increasing climatic variability (Bollig, 2006;Goldman and Riosmena, 2013;McCabe et al, 2010).…”