Consistent quantification of trypanosomes, the parasite responsible for African animal trypanosomosis, is important for effective surveillance, control, and eradication strategies. Here, we used a rigorously predefined protocol to search and select eligible publications that utilized either microscopy, serology, or molecular methods to investigate prevalence of trypanosomosis based on the presence of any of three most common Trypanosoma spp. (T. congolense, T. vivax, and T. brucei) in the field-based naturally grazed Gambian cattle, sheep, and goats. To combine results of studies on cattle through meta-analysis, sensitivity and subgroup analyses were carried out with the random effects model, and prevalence estimates of each study with 95% confidence intervals (CI) were presented with a forest plot. All the eligible studies utilized the buffy coat technique (BCT) to detect trypanosomes in the blood samples, while the more sensitive serological and molecular detection methods are yet to be widely exploited. Heterogeneity among the studies on cattle was moderate (I² = 55%), and the pooled trypanosomosis prevalence based on the BCT was 5.2% (95% CI: 4.0–6.4). Meanwhile, estimated prevalence varied according to the trypanosome detection methods, study locations, types of publication, year, and length of observations. We could not pool the trypanosomosis prevalence in sheep and goats through meta-analysis due to small number of studies. The prevalence estimates based on the BCT ranged from 3.2 to 8.1% in goats and 2.8 to 10.6% in sheep. Even though there seems to be a slight decrease in trypanosomosis prevalence in cattle in one of the Gambian districts, there was no consistent trend across the years. It is thought that the literature search and formatting procedures presented in this study contribute to doing systematic reviews on the investigated subject and can be adapted for similar cases.

锥虫体（负责非洲动物锥虫病的寄生虫）的定量定量对于有效的监测，控制和根除策略很重要。在这里，我们使用严格的预定义方案来搜索和选择符合条件的出版物，这些出版物使用显微镜，血清学或分子方法，根据三种最常见的锥虫病菌种的存在调查锥虫病的患病率。（T. congolense，T. vivax和T. brucei）在野外以自然方式放牧的冈比亚牛，绵羊和山羊。为了通过荟萃分析结合对牛的研究结果，使用随机效应模型进行了敏感性和亚组分析，并以森林图的形式给出了每项研究的流行率估计值和95％置信区间（CI）。所有符合条件的研究均利用血沉棕黄层技术（BCT）检测血样中的锥虫，而更灵敏的血清学和分子检测方法尚未得到广泛利用。在牛的研究中，异质性中等（I ² = 55％），基于BCT的合并锥虫病患病率为5.2％（95％CI：4.0-6.4）。同时，估计的患病率根据锥虫检测方法，研究地点，出版物类型，年份和观察时间长短而异。由于研究量少，我们无法通过荟萃分析汇总绵羊和山羊锥虫病的患病率。基于BCT的患病率估计在山羊中为3.2％至8.1％，在绵羊中为2.8％至10.6％。即使在冈比亚的一个地区，牛的锥虫病流行率似乎略有下降，但多年来却没有一致的趋势。可以认为，本研究中提出的文献检索和格式化程序有助于对所研究的主题进行系统的综述，并且可以适用于类似情况。