Sustainable interventions for an emerging livestock disease problem in Tanzania

该项目是针对牲畜饲养社区的关切而制定的，这些社区报告说，由于当地称为Ormilo的新出现的疾病问题，绵羊和山羊的死亡率大幅下降。我们的初步研究支持越来越多的共识，即Ormilo是一种脑性神经症，一种由绦虫感染（多头带绦虫）引起的绵羊和山羊的致命神经系统疾病。绵羊和山羊通过摄入狗（最终宿主）粪便中的寄生虫卵而感染，当寄生虫幼虫迁移到大脑并形成囊肿时，就会出现临床疾病。狗在食用受感染的绵羊和山羊的大脑时也会被感染。目前的神经症水平似乎是前所未有的，并引起最贫穷的畜牧家庭，特别是日益依赖绵羊和山羊维持生计和粮食安全的牧民的重大关切。在坦桑尼亚北部的大多数牧民社区，奥米洛病现在被列为最优先考虑的疾病。可能有几个因素导致了目前病例的激增，包括人们转而饲养小型反刍动物而不饲养牛，狗的数量迅速增加，以及家畜主人用受感染动物的大脑喂狗的做法。该项目旨在制定简单、可持续的干预措施，便于牲畜饲养者和狗主人采用，以预防感染和减轻疾病负担。该项目将侧重于两项干预措施：(a)向牲畜饲养者发展和传播有关寄生虫生命周期的文化上适当的信息，以及不将脑组织喂给狗的重要性（焚烧是一种简单的替代方法）；(b)每三个月用吡喹酮对狗进行除鼠治疗。驱虫犬的另一个重要好处是有效控制细粒棘球绦虫，它是人类包虫病（囊性棘球绦虫）的病因，这是一种潜在的致命疾病，已知是东非牧区一个重要但被忽视的人类健康问题。由于狗和小型反刍动物的生命周期类似，包虫病也可能增加，但病例在几年内不会变得明显。在这个阶段对狗进行有效的干预可以避免未来人类健康的重大问题。拟议项目的最后产出将是一项业务发展计划，其中列出了随后的补救Ormilo干预措施。该计划将在很大程度上取决于Ormilo是地方性的还是广泛/区域性的动物卫生问题，以及农民是否愿意支付吡喹酮治疗狗的费用。为更好地了解Ormilo问题的规模和对干预措施的需求而进行的市场研究将包括分析通过其他正在进行的研究、家庭计量经济学和支付意愿研究以及利益攸关方研讨会产生的详细的Ormilo患病率数据。进一步的工作将包括编写向牲畜饲养社区传播的材料，并为非政府组织和动物保健专业人员提供培训课程。通过与具有制定牲畜干预措施解决方案经验的项目伙伴（GALVmed）合作，我们将探索以非政府组织为基础的交付战略和以市场为主导的方法，通过这些方法，可以开发动物卫生供应链，向大量牲畜饲养者提供吡喹酮，并有可能扩展到东非地区的国家（例如东非国家）。肯尼亚和埃塞俄比亚)。

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).