National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-855, Japan; Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-855, Japan.
Laboratoire de diagnostic veterinaire et de serosurveillance de Parakou (LADISERO), Parakou, BP 23 Benin.
Ticks Tick Borne Dis. 2018 Mar;9(3):450-464. doi: 10.1016/j.ttbdis.2017.12.015. Epub 2017 Dec 28.
Babesiosis, theileriosis, anaplasmosis, and heartwater are tick-borne diseases (TBD) that threaten livestock production in sub-Saharan Africa including Benin. This country has been faced with an invasion of Rhipicephalus microplus, a major vector for babesiosis, theileriosis, and anaplasmosis over the last decade. Yet, data on TBD and the impact of the invasive ticks are lacking, making risk level evaluation and disease control arduous. In this study, epidemiological features of Babesia bovis, B. bigemina, Theileria spp., Anaplasma marginale and Ehrlichia ruminantium infections in Benin cattle were investigated in R. microplus-invaded and non-invaded areas. Detection of pathogens was based on species-specific PCR assays and resulting data were used to identify risk factors. Genetic diversity and phylogenies were then evaluated using several markers. Out of 207 samples examined, 170 (82.1%), 109 (52.7%), 42 (20.3%) 24 (11.6%) and 1 (0.5%) were positive for T. mutans, A. marginale, B. bigemina, B. bovis and E. ruminantium, respectively. Animal gender (for B. bovis), exposure to R. microplus (for B. bigemina and A. marginale), animal age (for B. bigemina and A. marginale) and cattle breed and/or antiprotozoal treatment (for T. mutants) significantly modulated pathogen occurrence. In addition, R. microplus exposure was significantly related to co-infection patterns and cases of clinical theileriosis and/or anaplasmosis were recorded among cattle highly exposed to the tick. In the genetic characterization, Theileria spp. and E. ruminantium sequences were conserved. Babesia spp. and A. marginale, however, showed high sequence polymorphisms that indicate the presence of several strains and may be linked to R. microplus invasion. Taken together, these results ascertain the endemicity of tick-borne infections in Benin and suggest that the characteristics of Babesia spp. and A. marginale infections in R. microplus-invaded and non-invaded areas are different.
巴贝斯虫病、泰勒虫病、无形体病和心水病是撒哈拉以南非洲包括贝宁在内的牲畜生产所面临的蜱传疾病（TBD）。在过去的十年中，该国一直面临着巴贝斯虫、泰勒虫和无形体病的主要传播媒介——微小牛蜱的入侵。然而，关于 TBD 和入侵蜱的影响的数据却很缺乏，这使得风险水平评估和疾病控制变得困难。在这项研究中，在微小牛蜱入侵和非入侵地区，调查了贝宁牛的巴贝斯虫、双芽巴贝斯虫、泰勒虫、边缘无形体和牛埃立克体感染的流行病学特征。病原体的检测基于种特异性 PCR 检测，所得数据用于确定风险因素。然后，使用多个标记物评估遗传多样性和系统发育。在检查的 207 个样本中，170 个（82.1%）、109 个（52.7%）、42 个（20.3%）、24 个（11.6%）和 1 个（0.5%）分别对 T. mutans、A. marginale、B. bigemina、B. bovis 和 E. ruminantium 呈阳性。动物性别（针对 B. bovis）、接触微小牛蜱（针对 B. bigemina 和 A. marginale）、动物年龄（针对 B. bigemina 和 A. marginale）以及牛品种和/或抗原生动物治疗（针对 T. mutans）显著调节了病原体的发生。此外，微小牛蜱的接触与合并感染模式显著相关，在高度接触蜱的牛中记录了临床泰勒虫病和/或无形体病病例。在遗传特征方面，泰勒虫和牛埃立克体序列保守。然而，巴贝斯虫和边缘无形体显示出高序列多态性，表明存在几种菌株，可能与微小牛蜱的入侵有关。综上所述，这些结果证实了贝宁的蜱传感染的流行，并表明微小牛蜱入侵和非入侵地区的巴贝斯虫和边缘无形体感染的特征不同。
