Mohammed-Ahmed G M, Hassan S M, El Hussein A M, Salih D A
Ministry of Animal Resources, El Obeid, Sudan.
University of Khartoum, P.O. Box 32, Khartoum North, Sudan.
Vet Parasitol Reg Stud Reports. 2018 Aug;13:24-29. doi: 10.1016/j.vprsr.2018.03.006. Epub 2018 Mar 29.
This survey was conducted to detect Theileria annulata infection in indigenous (Zebu) and cross (indigenous × Friesian) cattle (n 604) of different sex & age groups, and to investigate prevalence of ticks infesting cattle in North Kordofan State, Sudan. Ticks, blood smears, serum samples and blood spots on filter paper were collected from four municipalities at four monthly intervals during the period from August 2008 to July 2009. Out of 604 blood smears, 69 (11.4%, 95% CI: 16.9-5.9) were positive for Theileria piroplasms; whereas, out of 240 serum samples, 164 (68.3%, 95% CI: 89.3-47.3) were positive for antibodies against T. annulata using IFA test. Using PCR, out of 100 blood spots on filter paper, 8 (8%, 95% CI: 9.6-6.4) revealed T. annulata DNA. The highest prevalence of Theileria spp. piroplasms and T. annulata antibodies was recorded in August (15.9 ± 4.6) followed by February (13.3 ± 3.8) and the lowest was in May (3.9 ± 1.0). Among cattle breeds, the highest prevalence of piroplasms (11.9 ± 5.0) and T. annulata antibodies (68.9 ± 10) was among zebu cattle. PCR assays revealed the highest prevalence rate of T. annulata DNA in February (12.5 ± 1.4) followed by August (6.1 ± 0.7) and the lowest was in May (5.7 ± 0.7). According to cattle breeds, T. annulata DNA was detected in cross-bred cattle (3.3 ± 0.4) more than zebu cattle (10 ± 1.6). Seven tick species belonging to four genera and were identified, Amblyomma lepidum, Hyalomma dromedarii, H. impeltatum, H. rufipes, Rhipicephalus evertsi evertsi, Rhipicephalus decoloratus, R. annulatus. The most abundant tick species was H. rufipes followed by H. impeltatum, R. e. evertsi, H. dromedarii, R. decoloratus, A. lepidum and R. annulatus. Theileria annulata has been detected for the first time in North Kordofan State, though at a low prevalence rate. This finding is an alarming situation since tropical theileriosis is an emerging disease and it is widely believed that this economically important tick-borne parasite does not exist in this state. The possible alternative vector(s) of T. annulata in the absence of the known vector H. anatolicum is discussed.
本次调查旨在检测不同性别和年龄组的本地（瘤牛）和杂交（本地×弗里生）牛（n = 604）中的环形泰勒虫感染情况，并调查苏丹北科尔多凡州牛身上蜱虫的感染率。在2008年8月至2009年7月期间，每隔四个月从四个城市收集蜱虫、血涂片、血清样本和滤纸上的血斑。在604份血涂片中，69份（11.4%，95%置信区间：16.9 - 5.9）环形泰勒虫梨形虫呈阳性；而在240份血清样本中，使用间接荧光抗体试验检测，164份（68.3%，95%置信区间：89.3 - 47.3）抗环形泰勒虫抗体呈阳性。使用聚合酶链反应（PCR），在100份滤纸上的血斑中，8份（8%，95%置信区间：9.6 - 6.4）检测到环形泰勒虫DNA。泰勒虫属梨形虫和环形泰勒虫抗体的最高感染率出现在8月（15.9 ± 4.6），其次是2月（13.3 ± 3.8），最低是在5月（3.9 ± 1.0）。在牛的品种中，梨形虫（11.9 ± 5.0）和环形泰勒虫抗体（68.9 ± 10）的最高感染率出现在瘤牛中。PCR检测显示，环形泰勒虫DNA的最高感染率出现在2月（12.5 ± 1.4），其次是8月（6.1 ± 0.7），最低是在5月（5.7 ± 0.7）。根据牛的品种，杂交牛（3.3 ± 0.4）中检测到环形泰勒虫DNA的比例高于瘤牛（10 ± 1.6）。鉴定出属于四个属的七种蜱虫，即斑纹花蜱、单峰驼璃眼蜱、侵袭璃眼蜱、红足璃眼蜱、埃氏扇头蜱、脱色扇头蜱、环纹扇头蜱。最常见的蜱虫种类是红足璃眼蜱，其次是侵袭璃眼蜱、埃氏扇头蜱、单峰驼璃眼蜱、脱色扇头蜱、斑纹花蜱和环纹扇头蜱。首次在北科尔多凡州检测到环形泰勒虫，尽管感染率较低。这一发现令人担忧，因为热带泰勒虫病是一种新出现的疾病, 人们普遍认为该州不存在这种具有经济重要性的蜱传寄生虫。本文讨论了在已知传播媒介安纳托利亚璃眼蜱不存在的情况下，环形泰勒虫可能的替代传播媒介。
