Pathway to Peste des Petits Ruminants Virus Elimination - methods for complex ecosystems

小反刍动物疫病在亚洲和非洲各地的出现，影响到地球上一些最贫穷和最受挑战的人类社区，需要采取紧急行动，以减轻其对家养和野生反刍动物的直接和持续的潜在影响。PPR是一种非常严重的绵羊和山羊疾病，在东非非常常见，导致高达100%的死亡率，并导致牛奶和肉类的损失。它威胁着牧民和小农的粮食安全和生计。它还威胁着野生动物资源，正如亚洲稀有和濒危野生山羊的死亡所表明的那样。在过去几年中，在国际和国家一级就控制和可能根除PPR进行了大量讨论，并于2015年初启动了一项全球PPR根除方案。自2006-2008年肯尼亚和坦桑尼亚出现PPR以来，已经开展了几次疫苗接种运动，以限制其对牲畜饲养者的影响，但疫情仍在继续发生，而且缺乏有效的监测意味着不清楚该病毒是如何以及在哪里持续存在的。疫苗接种通常是在有资金的情况下应对疫情，这有助于减少牲畜饲养者因该疾病造成的直接损失，但疫苗接种覆盖率较低可能有助于病毒的持续存在。需要一种更务实但以研究为导向的方法，以阻止PPR病毒在东非以及在非洲、亚洲和欧洲的感染和高危地区持续和传播。该项目旨在研究大塞伦盖蒂生态系统中的野生动物和牲畜种群，它们如何相互作用，以及多个易感物种的相互作用如何有助于PPR感染的持续，使多宿主系统中的疾病控制比单一宿主系统更具挑战性。根据我们以前的研究，我们知道一些常见的野生动物物种可以感染PPR病毒，如水牛、角马、瞪羚等。我们不知道它们是否通过与绵羊和山羊的接触而感染，也不知道病毒是否在野生动物中独立传播。该项目将绘制牲畜和野生动物的数量、数量、迁移方式以及野生动物和牲畜之间的接触类型。它将通过进行血液采样调查来检测PPR抗体，以测量野生动物中PPR的感染水平。它将测量农民报告的绵羊和山羊群中疾病暴发的频率，并通过对农民的采访和对羊群的走访，在牲畜与野生动物接触的不同水平和模式的地点测量疾病暴发的频率。综合所有这些信息，我们将能够计划在短时间内在绵羊和山羊种群中进行PPR疫苗接种以消除感染的最佳方式，以及在小种群和野生动物中进行监测以监测PPR感染和疾病的最佳方式。该项目将由来自皇家兽医学院、伦敦大学学院和法国CIRAD的研究人员实施，与肯尼亚和坦桑尼亚兽医服务机构、研究人员、野生动物当局和当地机构合作。从这项研究中获得的宝贵信息将是从这一生态系统中消除PPR的第一步，所学到的经验教训将适用于非洲和亚洲的其他地区。除了获得新的知识外，减少PPR等疾病的影响将使这些地区的农民，特别是妇女能够提高生产力，改善其粮食安全和生计。这发生在向其他生计过渡的关键时刻，围绕土地使用、农业和生物多样性保护的紧张局势正在酝酿之中，气候变化和干旱的影响越来越大。更好的疾病控制将使人们在这一社会经济转型期间具有更强的适应能力。

The emergence of the viral disease, peste des petits ruminants (PPR) across Asia and Africa, affecting some of the poorest and most challenged human communities on earth, demands urgent action to mitigate its immediate and ongoing insidious impacts on domestic and wild ruminants. PPR is a very severe disease of sheep and goats that is very common in East Africa causing high mortality of up to 100%, and loss of milk and meat. It threatens the food security and livelihoods of pastoralists and small-holder farmers. It also threatens wildlife resources, as die-off of rare and endangered wild caprines in Asia has shown. Over the past few years there has been much discussion at international and national levels about the control and possible eradication of PPR, and in early 2015 a global PPR eradication programme was launched. Since the emergence of PPR in Kenya and Tanzania in 2006-2008, there have been several vaccination campaigns to limit its impact on livestock keepers but outbreaks continue to occur, and lack of effective surveillance means that it is unclear how and where the virus is persisting. Vaccination is usually applied in response to outbreaks if funds are available, which helps to reduce livestock keepers' immediate losses due to the disease, but low levels of vaccination coverage could be contributing to virus persistence. A more pragmatic but research-driven approach is needed to halt PPR virus persistence and spread in East Africa, as well as in infected and at-risk areas of Africa, Asia and Europe. The project aims to study the wildlife and livestock populations in the Greater Serengeti ecosystem, how they interact with each other, and how the interaction of multiple susceptible species might contribute to persistence of PPR infection making disease control more challenging in a multi-host compared to a single host system. Based on our previous studies we know that some common wildlife species can be infected with PPR virus, such as buffalo, wildebeest, gazelles and others. We do not know whether they are becoming infected by contact with sheep and goats, or whether the virus is circulating independently among wildlife.The project will map the livestock and wildlife populations, their numbers, how they move and the type of contact between wildlife and livestock. It will measure the level of PPR infection in the wildlife by conducting a blood-sampling survey to test for PPR antibodies. It will measure the frequency of disease outbreaks in sheep and goat flocks as reported by farmers and through interviews with farmers and flock visits, in sites with different levels and patterns of livestock-wildlife contact. Putting all this information together, we will be able to plan the best way to carry out PPR vaccination in the sheep and goat population to eliminate infection in a short period of time, and the best way to carry out surveillance in both small stock and wildlife to monitor PPR infection and disease.The project will be carried out by researchers from the Royal Veterinary College, University College London and CIRAD, France, working together with Kenyan and Tanzanian veterinary services, researchers and wildlife authorities and local institutions, and the local livestock keeping communities.The valuable information gained from this study will be the first step towards eliminating PPR from this ecosystem and the lessons learned will be applicable in other parts of Africa and Asia. In addition to the new knowledge gained, reducing the impact of diseases like PPR will allow farmers, particularly women, in these areas to be more productive, to improve their food security and livelihoods. This comes at a critical time of transition to other livelihoods, with simmering tensions around land use, agriculture and biodiversity conservation, and the increasing effects of climate change and drought. Better disease control will allow people to be more resilient during this socio-economic transition.