Equine trypanosomiasis is a severe and prevalent disease that has the greatest impact globally upon working equids due to its distribution across lower income countries. Morbidity and mortality rates are high; disease management strategies in endemic regions are ineffective and cost prohibitive. Individual variation in disease phenotype in other species suggests host factors could reveal novel treatment and control targets but has not been investigated in equids. A prospective clinical evaluation of equines presenting for a free veterinary examination was performed in hyperendemic villages in The Gambia. Age, body condition score and body weight were estimated by validated methods, and haematocrit and total protein concentration measured. Animals fulfilling 2 out of 5 clinical inclusion criteria (anaemia, poor body condition, pyrexia, history of abortion, oedema) for a diagnosis of trypanosomiasis received trypanocidal treatment with follow-up at 1 and 2 weeks. Blood samples underwent PCR analysis with specific Trypanosoma spp. primers and results were compared to the subject’s clinical and clinicopathological features. A mixed effects generalised linear model was generated to evaluate the association of infection status with degree of pyrexia and anaemia. Morbidity was high within examined (n = 641) and selected (n = 247) study populations. PCR status was not associated with a defined disease phenotype; there was intra- and inter-species variability. Donkeys were more frequently Trypanosoma spp.-positive (P < 0.001) and febrile (P < 0.001) than horses, but infected horses were more anaemic (P < 0.001), and in poorer body condition (P < 0.001) than donkeys. Sex was correlated to disease phenotype: males were more anaemic (P = 0.03) and febrile (P < 0.001). Haemoparasite co-infections were more common than a single infection. There was evidence of diversity in trypanosomiasis clinical signs plus variable disease phenotypes within equid subpopulations that warrant further investigation. The complex co-infection profile of field cases requires greater consideration to optimise disease management.

中文翻译：

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马锥虫病显示出明显的疾病表型

马锥虫病是一种严重且普遍的疾病，由于其在低收入国家中的分布，在全球范围内对劳动者的影响最大。发病率和死亡率很高；流行地区的疾病管理策略无效且成本过高。其他物种在疾病表型上的个体差异表明宿主因素可以揭示新的治疗和控制目标，但尚未进行过研究。在冈比亚的高流行性村庄中对进行免费兽医检查的马进行了前瞻性临床评估。通过验证的方法估算年龄，身体状况评分和体重，并测量血细胞比容和总蛋白浓度。符合5个临床纳入标准中的2个的动物（贫血，身体状况不佳，发热，诊断为锥虫病的流产史，水肿）接受锥虫杀灭治疗，并在第1和2周进行随访。血样经过特异锥虫的PCR分析。将引物和结果与受试者的临床和临床病理特征进行比较。生成了混合效应广义线性模型，以评估感染状况与发热和贫血程度之间的关系。在接受检查的人群（n = 641）和选定的研究人群（n = 247）中，发病率很高。PCR状态与确定的疾病表型无关。种内和种间存在变异。驴比马更常出现锥虫阳性（P <0.001）和发热（P <0.001），但受感染的马比驴更贫血（P <0.001），身体状况较差（P <0.001）。性别与疾病表型相关：男性贫血（P = 0.03）和发热（P <0.001）。血寄生虫合并感染比单一感染更为常见。有证据表明，在等量的亚群中，锥虫病的临床体征加上疾病表型的多样性，值得进一步研究。现场病例复杂的共感染情况需要更多考虑，以优化疾病管理。