这项工作研究了Stomoxyscalitrans对间日锥虫的机械传播在没有循环载体的地区。这项研究涉及两个实验,一只小牛实验感染了间日疟原虫,在锥虫病的急性期(实验1)和其他慢性期(实验2)。在这两个实验中,对未喂食24小时或从未喂食的苍蝇使用了两种传播方法:(i)方法1:在牛栏中自由释放的苍蝇(约3,300只苍蝇/围栏持续10天);(ii)方法2:将苍蝇放在喂食室中(12只苍蝇/动物)。在两个实验(急性期和慢性期)中开发方法1,间日疟原虫阳性动物与间日疟原虫阴性动物一起饲养。定期,Brener方法,Woo方法,血液涂片,cPCR,ELISA,IFAT,进行Inmunoteste®和Inmunoteste®以检测动物中的间日疟原虫。我们还记录了动物的头和蹄子,以及围栏内壁附近的苍蝇数量。随后,使用羔羊进行生物测试。对于两个实验中的方法2,喂食室内的苍蝇首先喂食间日疟原虫阳性动物,然后喂食阴性动物。在实验和方法中,我们通过血液涂片和鼻和腹部的cPCR检查了果蝇中是否存在间日疟原虫。在实验2(慢性期)中,进行了一项测试,以确定在具有不同寄生虫血症水平的动物的血液中可以存活多长时间。没有动物(小牛和羔羊)被间日疟原虫感染或显示抗体。在评估期间,与没有苍蝇的动物(对照)相比,有苍蝇的动物表现出更多的踩踏和抛头。此外,实验期间,围栏中的苍蝇数量增加了。仅在实验1(急性期)中,在果蝇的腹部但在长鼻中发现了间日疟原虫和DNA。在实验2(慢性期)中,每毫升血液中更高的色素动物浓度与该阶段寄生虫的寿命较短有关。总之,在实验的可变条件下(宿主,苍蝇的数量,和寄生虫血症水平),S、骨灰质无法将间日疟原虫机械传播给牛。
This work investigated the mechanical transmission of Trypanosoma vivax by Stomoxys calcitrans to cattle in a region without a cyclic vector. The study involved two experiments, one with calves experimentally infected with T. vivax, in the acute phase of trypanosomosis (Experiment 1) and the other in the chronic phase (Experiment 2). In both experiments, two transmission methods were used with flies that had not fed for 24 h or had never fed: (i) Method 1: flies released freely in cattle pens (≈3,300 flies/pen for 10 days); and (ii) Method 2: flies placed in a feeding chamber (12 flies/animal). To develop Method 1 in the two experiments (acute and chronic phases), T. vivax-positive animals were kept with T. vivax-negative animals. Periodically, the Brener method, Woo method, blood smears, cPCR, ELISA, IFAT, and Imunoteste® were performed to detect T. vivax in the animals. We also recorded the animals\' head tossing and hoof stomping and the number of flies near the pens\' inner walls. Subsequently, biological testing was performed using lambs. For Method 2 in both experiments, flies inside the feeding chamber first fed on T. vivax-positive animals and later on negative animals. In both experiments and methods, we examined the flies for the presence of T. vivax through blood smears and cPCR of the proboscis and abdomen. In Experiment 2 (chronic phase), a test was conducted to determine how long trypomastigotes forms could survive on the blood of animals with different levels of parasitemia. None of the animals (calves and lambs) became infected with T. vivax or showed antibodies against it. During the evaluation period, the animals in the presence of the flies exhibited more hoof stomping and head tossing compared to those without flies (control). Additionally, there was an increase in the number of flies in the pens during the experiment. Only in Experiment 1 (acute phase) were T. vivax trypomastigotes and DNA found in the abdomen of the flies but not in the proboscis. In Experiment 2 (chronic phase), higher concentrations of trypomastigotes per milliliter of blood were associated with a shorter the lifespan of this stage of the parasite. In conclusion, under the variable conditions of the experiments (hosts, number of flies, and level of parasitemia), S. calcitrans was unable to mechanically transmit T. vivax to cattle.