Molecular epidemiology network for promotion and support of delivery of live vaccines against Theileria parva and Theileria annulata infection in Eastern and Northern Africa

在发展中世界热带和亚热带大部分地区流行的蜱传疾病，如蜱传菌病，在对资源贫乏的农业社区生计的影响方面排名很高。蛲虫病（由细小蛲虫引起的东海岸热和由环状绦虫引起的热带蛲虫病）被认为是该病流行地区牲畜发展的主要制约因素。目前，对蜱虫病和其他蜱传疾病的管理主要是通过使用杀螨剂控制蜱病媒介，尽管由于杀螨剂耐药性和食品安全问题日益严重，这是不可持续的。在一些国家，长期以来一直有一种非常有效的“感染和治疗”活疫苗用于控制东海岸热，这种活疫苗是基于注射可能致命剂量的孢子虫和长效剂量的四环素。然而，人们担心通过这种疫苗将外来寄生虫引入一个地区可能会导致新的毒性更强的基因型。因此，这种疫苗没有在苏丹等其他一些国家应用，尽管对疫苗接种有迫切的需求。在北非、中东和南亚，一种通过体外传代培养减毒的分裂感染白细胞接种的活疫苗已被用于控制该病，但尚未在同样发现该病的东非、埃及和苏丹地区建立。该项目的目的将是在这些区域确定寄生虫菌株的分子特征，并确定适合研制活疫苗的细小绦虫和环状绦虫菌株。该项目将导致通过生产疫苗转让特定疾病诊断、疾病监测、管理和控制所需的技术。

Tick-borne diseases, such as theileriosis, which are endemic in large parts of tropical and subtropical regions of the developing world, are ranked high in terms of their impact on the livelihood of resource poor farming communities. Theileriosis (East Coast fever caused by Theileria parva and tropical theileriosis caused by T. annulata) is considered a major constraint for development of livestock in regions where the disease is endemic. Currently, management of theileriosis and other tick-borne diseases is primarily through control of the tick vector using acaricides, although this is unsustainable due to increasing acaricide resistance and food safety concerns. A highly effective ‘infection and treatment’ live vaccine based on the injection of a potentially lethal dose of sporozoites together with a long acting dose of tetracycline has long been available for control of East coast fever in a number of countries. However, there are fears that the introduction of foreign parasites by this vaccination to a region might result in novel more virulent genotypes. Therefore, this vaccine was not applied in a number of other countries like the Sudan, although there is an urgent demand for vaccination. For T. annulata a live vaccine based on inoculation of schizont-infected leukocytes attenuated through passage in in vitro culture has been utilised for control and is deployed in North Africa, the Middle East and South Asia, but has not been established in regions of East Africa, Egypt and Sudan, where the disease is also found. The aim of the project will be to molecularly characterize parasite strains in the regions and to identify strains of T. parva and T. annulata suitable for the development of live vaccines. The project will result in the transfer of technologies required for specific diagnosis of the diseases, disease surveillance, management and control by producing vaccines.