Asmare Kassahun, Abayneh Takele, Sibhat Berhanu, Shiferaw Dessie, Szonyi Barbara, Krontveit Randi I, Skjerve Eystein, Wieland Barbara
School of Veterinary Medicine, Hawassa University, P.O. Box 005, Hawassa, Ethiopia.
College of Veterinary Medicine and Agriculture, Addis Ababa University, P.O. Box 34, Debre-Zeit, Ethiopia.
Acta Trop. 2017 Jun;170:95-104. doi: 10.1016/j.actatropica.2017.02.015. Epub 2017 Feb 14.
Vector-borne diseases are among major health constraints of small ruminant in Ethiopia. While various studies on single vector-borne diseases or presence of vectors have been conducted, no summarized evidence is available on the occurrence of these diseases and the related vectors. This systematic literature review provides a comprehensive summary on major vectors and vector-borne diseases in small ruminants in Ethiopia. Search for published and unpublished literature was conducted between 8th of January and 25th of June 2015. The search was both manual and electronic. The databases used in electronic search were PubMed, Web of Science, CAB Direct and AJOL. For most of the vector-borne diseases, the summary was limited to narrative synthesis due to lack of sufficient data. Meta-analysis was computed for trypanosomosis and dermatophilosis while meta-regression and sensitivity analysis was done only for trypanososmosis due to lack of sufficient reports on dermatophilosis. Owing emphasis to their vector role, ticks and flies were summarized narratively at genera/species level. In line with inclusion criteria, out of 106 initially identified research reports 43 peer-reviewed articles passed the quality assessment. Data on 7 vector-borne diseases were extracted at species and region level from each source. Accordingly, the pooled prevalence estimate of trypanosomosis was 3.7% with 95% confidence interval (CI) 2.8, 4.9), while that of dermatophilosis was 3.1% (95% CI: 1.6, 6.0). The in-between study variance noted for trypanosomosis was statistically significant (p<0.05). Among the three covariates considered for meta-regression, only one (species) fitted the final model significantly (p<0.05) and explained 65.44% of the between studies variance (R). The prevalence in sheep (5.5%) increased nearly by 34% compared to goats (2.9%). The parasitic presence in blood was documented for babesiosis (3.7% in goats); and anaplasmosis (3.9% in sheep). Serological evidence was retrieved for bluetongue ranging from 34.1% to 46.67% in sheep, and coxiellosis was 10.4% in goats. There was also molecular evidence on the presence of theileriosis in sheep (93%, n=160) and goats (1.9%, n=265). Regarding vectors of veterinary importance, 14 species of ticks in five genera, four species of Glossina and 4 genera of biting flies were reported. Despite the evidence on presence of various vectors including ticks, flies, mosquitoes and midges, studies on vector-borne diseases in Ethiopia are surprisingly rare, especially considering risks related to climate change, which is likely to affect distribution of vectors. Thus better evidence on the current situation is urgently needed in order to prevent spread and to model future distribution scenarios.
媒介传播疾病是埃塞俄比亚小型反刍动物面临的主要健康制约因素之一。虽然已经对单一媒介传播疾病或媒介的存在进行了各种研究，但尚无关于这些疾病和相关媒介发生情况的汇总证据。本系统文献综述全面总结了埃塞俄比亚小型反刍动物的主要媒介和媒介传播疾病。于2015年1月8日至6月25日期间进行了已发表和未发表文献的检索。检索方式包括手动检索和电子检索。电子检索使用的数据库有PubMed、科学网、CAB Direct和AJOL。对于大多数媒介传播疾病，由于缺乏足够数据，综述仅限于叙述性综合分析。对锥虫病和皮肤真菌病进行了荟萃分析，而由于关于皮肤真菌病的报告不足，仅对锥虫病进行了元回归和敏感性分析。由于蜱和苍蝇的媒介作用，在属/种水平上对其进行了叙述性总结。根据纳入标准，在最初确定的106篇研究报告中，有43篇经过同行评审的文章通过了质量评估。从每个来源提取了关于7种媒介传播疾病的物种和地区层面的数据。因此，锥虫病的合并患病率估计为3.7%，95%置信区间（CI）为2.8, 4.9），而皮肤真菌病的合并患病率为3.1%（95% CI：1.6, 6.0）。锥虫病研究间的方差具有统计学意义（p<0.05）。在考虑用于元回归的三个协变量中，只有一个（物种）显著拟合了最终模型（p<0.05），并解释了研究间方差的65.44%（R）。绵羊的患病率（5.5%）比山羊（2.9%）高出近34%。记录了血液中存在的巴贝斯虫病（山羊中为3.7%）和无形体病（绵羊中为3.9%）。检索到绵羊蓝舌病的血清学证据，范围在34.1%至46.67%之间，山羊的柯氏杆菌病为10.4%。也有分子证据表明绵羊（93%，n = 160）和山羊（1.9%，n = 265）中存在泰勒虫病。关于具有兽医重要性的媒介，报告了5个属的14种蜱、4种舌蝇属和4个属的叮咬蝇。尽管有证据表明存在包括蜱、苍蝇、蚊子和蠓在内的各种媒介，但埃塞俄比亚关于媒介传播疾病的研究出奇地少，特别是考虑到与气候变化相关的风险，气候变化可能会影响媒介的分布。因此，迫切需要更好的关于当前状况的证据，以防止传播并模拟未来的分布情况。
