Sustainable interventions for an emerging livestock disease problem in Tanzania

Lead Research Organisation: University of Glasgow
Department Name: College of Medical, Veterinary &Life Sci

Abstract

This project has been developed in response to concerns of livestock-keeping communities who have reported major mortality losses in sheep and goats due to an emerging disease problem, known locally as Ormilo. Our preliminary studies support a growing consensus that Ormilo is the disease cerebral coenurosis, a fatal, neurological disease of sheep and goats caused by a tapeworm infection (Taenia multiceps). Sheep and goats are infected by ingesting the parasite eggs shed in the faeces of dogs (the definitive host), with clinical disease occurring when the parasite larvae migrate to the brain and form cysts. Dogs are in turn infected when they consume the brains of affected sheep and goats.

Current levels of coenurosis appear to be unprecedented and a cause of major concern among the poorest livestock-keeping families, particularly pastoralists who are increasingly dependent on sheep and goats for livelihoods and food security. Ormilo is now ranked as the highest priority disease in most pastoral communities of northern Tanzania. Several factors may be contributing to the current upsurge in cases including a shift to keeping of small ruminants in preference to cattle, a rapid increase in dog populations, and the practice of livestock-owners of feeding dogs the brains of affected animals.

This project aims to develop simple, sustainable interventions that can be adopted easily by livestock-keepers and dog-owners to prevent infection and reduce the burden of disease. The project will focus on two interventions: (a) developing and disseminating culturally-approrpriate information to livestock-keepers on the life cycle of the parasite, and the importance of not feeding brain tissue to dogs (with burning a simple alternative); (b) anthelminthic treatment of dogs with praziquantel every three months. An important additional benefit of de-worming dogs would be the effective control of Echinococcus granulosus, the cause of human hydatid disease (cystic echinococcus), a potentially fatal disease which is known to be an important but neglected human health problem in pastoral communities of East Africa. With a similar life-cycle involving dogs and small ruminants, hydatid disease may also be increasing, but cases will not become apparent for several years. An effective intervention in dogs at this stage could avert a major future human health problem.

The final output of the proposed project will be a business development plan, which charts a subsequent course of remedial Ormilo intervention. The plan will depend to a large extent on whether Ormilo is a localised or widespread/regional animal health issue and the willingness of farmers to pay for praziquantel treatment of dogs. Market research to better understand the scale of the Ormilo problem and demand for interventions will involve analysis of detailed Ormilo prevalence data being generated through other on-going studies, household econometric and wilingness-to-pay studies, as well as stakeholder workshops. Further work will involve development of materials for dissemination to livestock-keeping communities and training courses for NGOs and animal health professions. By working with project partners with experience of developing solutions for livestock interventions (GALVmed), we will explore both NGO-based delivery strategies and market-led approaches through which animal health supply chains could be developed for delivery of praziquantel to a large population of livestock-keepers, potentially extending to countries in the East African region (eg. Kenya and Ethiopia).

Publications

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Description This grant contributed to a study of the causes and prevalence of a neurological syndrome in small ruminants which is a growing cause of concern to pastoralists in northern Tanzania. In total, 95% of surveyed households reported cases of neurological syndrome in the previous 12 months. By village, the 12-month period prevalence ranged from 11-34%, representing a total loss of about 10,000 affected animals. Dog ownership and the practice of feeding livestock brains to dogs were both identified as significant risk factors at the household level. Cysts consistent with Taenia multiceps infection were detected in the brain or spinal cord of 82% of clinically-affected animals (n=39) that underwent post-mortem examination. Coenurosis associated with T. multiceps infection is typically fatal, and can lead to substantial financial and production losses for livestock-dependent communities through death, predation or via premature slaughter of affected animals and a reduced market value. Our findings highlight the importance of this neglected livestock disease problem and the urgent need to implement effective control measures to control this disease in pastoral communities in Tanzania.
Exploitation Route These findings are being disseminated through a series of blogs, as well as through meetings with GALVmed and the International Veterinary Vaccinology network. Discussions are underway with research partners to develop protocols for a potential vaccine trial of a small ruminant vaccine against T. multiceps in Tanzania.

These results have also informed the design of larger-scale cross-sectional studies to assess the prevalence and impact of coenurosis across a wider range of agro-ecological settings in Tanzania (as part of a PhD study with a Tanzanian student from the Nelson Mandela African Institution of Science and Technology).
Sectors Agriculture, Food and Drink

 
Description Final SEEDZ Workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The SEEDZ project hosted a final two-day workshop in Arusha and invited a number of Tanzanian stakeholders to attend including representatives from the Tanzanian One Health Coordination Desk, TVLA, NIMR, MoH&SW, Ministry of Livestock and Fisheries, and FAO ECTAD, the Norhern Zonal Veterinary Centre (ZVC) and District Veterinary Officers from Karatu, Mbulu, Meru, Longido, Babati, Monduli, Simanjiro and Arusha District Coucils. Community leaders and local and international NGOs also attended, including GALVmed and Haki Kazi Catalyst. Researchers from Tanzanian and International institutions were also in attendance, including the University of Glasgow, Institute of Development Studies, Washington State University, University of Otago, Duke University, Scotland's Rural College, Kilimanjaro Christian Medical University College, Soikoine University of Africulture, University of Dar es Salaam and the International Livestock Research Institute. The first day was attended by 69 people and provided an overview of the work being carried out across Tanzania as part of the ZELS programme, including outputs from the SEEDZ, HAZEL and Brucella projects and the Life on the Edge project. The second day involved a participatory problem-solving session using Ketso? tools and focussed on interventions and policy implications of the research presented on the first day.
Year(s) Of Engagement Activity 2018
 
Description SEBI-TZ, Tanzanian Veterinary Association, 5-8 December 2018, Arusha Tanzania 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A presentation at Tanzanian Veterinary Association 'Supporting Evidence Based Interventions - Causes and Extent of Reproductive Loss and Mortality of Domestic Ruminants in Tanzania (SEBI-TZ)' , 5-8 December 2018, Arusha Tanzania
Year(s) Of Engagement Activity 2018
 
Description Taenia multiceps coenurosis in Tanzania: a major and under-recognised livestock disease problem in pastoral communities, Tanzanian Veterinary Association, 5-8 December 2018, Arusha Tanzania 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A presentation at Tanzanian Veterinary Association Taenia multiceps coenurosis in Tanzania: a major and under-recognised livestock disease problem in pastoral communities' , 5-8 December 2018, Arusha Tanzania
Year(s) Of Engagement Activity 2018