Sustainable interventions for an emerging livestock disease problem in Tanzania

该项目是针对畜牧业社区的关切而制定的，这些社区报告说，由于一种新出现的疾病问题，绵羊和山羊的死亡率大幅下降，这种疾病在当地被称为Ormilo。我们的初步研究支持了一个越来越多的共识，即Ormilo是脑多头蚴病，一种由绦虫感染（多头带绦虫）引起的绵羊和山羊致命的神经系统疾病。绵羊和山羊被寄生虫卵感染，寄生虫卵在狗（最终宿主）的粪便中脱落，当寄生虫幼虫迁移到大脑并形成囊肿时，就会发生临床疾病。当狗食用受感染的绵羊和山羊的大脑时，它们也会被感染。目前多头蚴病的程度似乎是前所未有的，是最贫穷的畜牧家庭，特别是越来越依赖绵羊和山羊维持生计和粮食安全的牧民的主要关切。在坦桑尼亚北方的大多数牧区，Ormilo现在被列为最优先的疾病。有几个因素可能导致目前病例的激增，包括转向饲养小型反刍动物而不是牛，狗的数量迅速增加，以及畜牧业者用受影响动物的大脑喂狗的做法。该项目旨在开发简单、可持续的干预措施，使畜牧业者和狗的主人能够容易地采用这些措施，以预防感染并减轻疾病负担。该项目将侧重于两项干预措施：（a）制定并向畜牧业者传播关于寄生虫生命周期的文化上适当的信息，以及不将脑组织喂狗的重要性（简单的替代办法是焚烧）;（B）每三个月用吡喹酮对狗进行驱虫治疗。驱虫犬的一个重要的额外益处是有效控制细粒棘球绦虫，细粒棘球绦虫是人类包虫病（囊状棘球绦虫）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相似，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。拟议项目的最终成果将是一个业务发展计划，其中绘制了Ormilo干预治疗的后续过程。该计划将在很大程度上取决于Ormilo是否是一个局部或广泛/区域的动物健康问题，以及农民是否愿意支付吡喹酮治疗狗的费用。为了更好地了解Ormilo问题的规模和对干预措施的需求，将进行市场研究，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讲习班产生的详细的Ormilo流行率数据。进一步的工作将包括编写材料，分发给畜牧业社区，并为非政府组织和动物保健专业人员举办培训班。通过与具有开发牲畜干预解决方案（GALVmed）经验的项目合作伙伴合作，我们将探索基于非政府组织的交付战略和市场主导的方法，通过这些方法可以开发动物健康供应链，向大量牲畜饲养者提供吡喹酮，并可能扩展到东非地区的国家（例如非洲）。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).