Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, P.O.B 12, Rehovot 7610001, Israel.
Ticks Tick Borne Dis. 2020 May;11(3):101384. doi: 10.1016/j.ttbdis.2020.101384. Epub 2020 Jan 27.
Stress has been suggested as a risk factor for Theileria equi peracute disease and may lead to relapse in clinical signs in chronically infected horses. The aim of this study was to assess the effect of stress on T. equi parasitemia in sub-clinically infected horses in two settings: horses hospitalized at a veterinary teaching hospital and horses from an endurance farm. Blood samples were collected from the hospitalized horses (n = 32) upon admission (T0) and at discharge (T1) from the hospital, and results were compared between horses that underwent surgery (stress) and other hospitalized horses (control). Blood samples were collected from an endurance farm (n = 20) six weeks before (T0) and two days after (T1) participation in an 80-km endurance event, and results were compared between horses that participated (stress) or did not participate (control) in the event. Theileria equi parasite load was determined using qPCR, and T1/T0 ratio was calculated for each horse. Mean parasite load at both time points did not differ statistically between the stress group and the controls in both settings. Theileria equi genotype was determined based on the 18S rRNA gene, when possible. Parasite genotypes were similar to strains previously characterized in the region and classified as genotypes A and D. The results of this study contradict the common assumption that stress may lead to increased parasite load in horses with a subclinical T. equi infection.
应激已被认为是马媾疫急性病的一个风险因素，并可能导致慢性感染马的临床症状复发。本研究的目的是评估应激对两种情况下亚临床感染马的马媾疫寄生虫血症的影响：住院兽医教学医院的马和耐力农场的马。从住院的马（n=32）入院时（T0）和出院时（T1）采集血液样本，并比较接受手术（应激）和其他住院马（对照组）的结果。从耐力农场（n=20）采集血液样本，在参加 80 公里耐力赛之前六周（T0）和两天后（T1），并比较参加（应激）或不参加（对照组）比赛的马的结果。使用 qPCR 确定马媾疫寄生虫载量，并计算每匹马的 T1/T0 比值。在这两种情况下，应激组和对照组在两个时间点的平均寄生虫载量在统计学上没有差异。根据 18S rRNA 基因确定马媾疫基因型，在可能的情况下。寄生虫基因型与该地区以前描述的菌株相似，并分类为 A 型和 D 型。本研究结果与应激可能导致亚临床 T. equi 感染马寄生虫载量增加的常见假设相矛盾。
