Abstract：
Ticks are leading vectors of economically important pathogens that affect small ruminants due to favourable climatic conditions across different regions of the African continent. They are responsible for both direct and indirect economic losses in the livestock industry. This review focuses on the species diversity of hard ticks, their biology, tick-borne diseases of sheep and goats including non-infectious disease, and risk factors to tick infestation in Africa. Furthermore, our review provides recent updates on distribution of ticks and tick-borne pathogens of small ruminants in Africa. It was observed that several species and subspecies of hard ticks belonging to the genera Hyalomma (Hy), Rhipicephalus (Rh), Ixodes (I) and Amblyomma (Am) were found infesting small ruminants across the different regions of the continent. Of these genera, Rhipicephalus ticks accounts for the majority of the registered species, with exactly 27 different species infesting small ruminant stocks comprising of different developmental instars and adults of the tick. Rhipicephalus decolaratus, Rh. e. evertsi and Rh. appendiculatus were the three most common Rhipicephalus species reported. Both protozoal (Babesia and Theileria) and bacterial (Anaplasma, Rickettsia, Ehrlichia, Coxiella and Mycoplasma) pathogens have being reported to be amplified in several hard tick species and/or small ruminant hosts. Furthermore, tick paralysis and lameness were non-infectious conditions attributed to tick infestations. Amblyomma hebraeum and Rh. glabroscutatum may cause lameness in goats, while Hy. rufipes is responsible for the same condition in Merino sheep. Host paralysis due to a neurotoxin released by female Rh. e. evertsi and I. rubicundus has been documented within the continent. We therefore advocate for the need of integrated control measures against tick-borne pathogens (TBPs) including their arthropod vectors, to be performed simultaneously to ease the burden of vector-borne diseases in small ruminant production.
摘要：
由于非洲大陆不同地区的有利气候条件，蜱是影响小反刍动物的重要经济病原体的主要载体。他们对畜牧业的直接和间接经济损失负责。这篇综述的重点是硬蜱的物种多样性，他们的生物学,绵羊和山羊的蜱传疾病，包括非传染性疾病，以及非洲蜱虫感染的危险因素。此外，我们的综述提供了非洲小反刍动物蜱和蜱传病原体分布的最新情况.观察到属于Hyalomma（Hy）属的硬蜱的几种和亚种，Rhipicephalus(Rh),在该大陆的不同地区发现了Ixodes（I）和Amblyomma（Am）感染小反刍动物。在这些属中，触毛蜱占登记物种的大部分,恰好有27种不同的物种侵染了小反刍动物种群，这些种群由tick的不同发育幼虫和成虫组成。去象形虫,Rh.e.evertsi和Rh。阑尾是所报道的三种最常见的动物。原生动物（Babesia和Theileria）和细菌（Anaplasma，立克次体,埃里希亚,据报道，柯西氏菌和支原体）病原体在几种硬蜱物种和/或小反刍动物宿主中被扩增。此外，蜱瘫痪和跛行是归因于蜱感染的非感染性疾病。Amblyommahebraeum和Rh。glabroscutatum可能导致山羊跛行，而Hy.rufipes是造成美利奴羊相同状况的原因。由于女性Rh释放的神经毒素引起的宿主瘫痪。e.evertsi和I.rubicundus在该大陆有记载。因此，我们主张需要对蜱传病原体（TBP），包括其节肢动物媒介采取综合控制措施，同时进行，以减轻小型反刍动物生产中媒介传播疾病的负担。
