Department of Zoology, Abdul Wali Khan University Mardan, Mardan, Pakistan.
Department of Infectious Diseases and Public Health, City University of Hong Kong, Hong Kong SAR, China.
Parasitol Res. 2022 Sep;121(9):2481-2493. doi: 10.1007/s00436-022-07596-3. Epub 2022 Jul 15.
Tick infestation is a major public and animal health concern causing significant financial losses, especially in tropical and subtropical regions of the world. This study aimed at investigating the epidemiologic profile of ticks infesting cattle and molecular identification of R. microplus in the centrally ignored part of Khyber Pakhtunkhwa, Pakistan. A total of 600 cattle from 20 farms were examined for the tick infestation, among them 358 (59.7%) cattle were infested with ticks. A total of 2118 nymph, larvae and adult tick stages were collected and morphologically identified followed by molecular confirmation of Rhipicephalus microplus. Host-based demographic and ecological parameter analysis revealed significantly higher tick infestation in adult, female, exotic, freely grazing, and with irregular/no acaricides treated cattle. The univariate logistic analysis showed that host age, gender, breed, acaricides use, and feeding method were significantly (P < 0.05) associated, whereas multivariate analysis revealed only host breed and feeding method were potential risk factors (P < 0.05) for tick infestation. Microscopy-based examination identified four different species of ticks including R. microplus (44.5%), Hyalomma anatolicum (38.5%), and Hyalomma marginatum (10.5%) and Hyalomma excavatum (6.5%). Tick infestation pattern showed that 55.9% of cattle was found co-infested with R. microplus and H. anatolicum followed by R. microplus and H. anatolicum and H. marginatum (29.3%) then R. microplus, H. anatolicum, H. marginatum, and H. excavatum (11.2%). Sequencing of the second internal transcribed spacer (ITS2-) and 16S rRNA gene fragments also confirmed the molecular identification of Rhipicephalus microplus. Phylogenetic analysis of ITS-2 revealed all sequences clustered in single clade of the R. microplus while the 16S rRNA nucleotide sequences showed that R. microplus in this study was clustered together in clade A along with other isolates from Pakistan, China, and India. The high tick infestation suggests the need for designing strategic and integrated control measures for ticks in order to ensure good health of domestic animals in this region of Pakistan.
蜱虫滋生是一个重大的公共卫生和动物健康问题，会造成巨大的经济损失，尤其是在世界上的热带和亚热带地区。本研究旨在调查巴基斯坦开伯尔-普赫图赫瓦省被忽视地区的牛蜱滋生的流行病学特征，并对其进行 R. microplus 的分子鉴定。从 20 个农场中抽取了 600 头牛进行蜱虫感染检查，其中 358 头（59.7%）感染了蜱虫。共采集、分离并鉴定了 2118 只若虫、幼虫和成虫阶段的蜱虫，并通过分子鉴定确认了 Rhipicephalus microplus 的存在。基于宿主的人口统计学和生态学参数分析显示，成年、雌性、外来、自由放牧且未使用杀蜱剂处理的牛蜱虫感染率更高。单因素逻辑分析表明，宿主年龄、性别、品种、杀蜱剂使用情况和喂养方式与蜱虫感染显著相关（P<0.05），而多因素分析显示，仅宿主品种和喂养方式是蜱虫感染的潜在危险因素（P<0.05）。基于显微镜的检查确定了四种不同的蜱虫种类，包括 R. microplus（44.5%）、Hyalomma anatolicum（38.5%）、Hyalomma marginatum（10.5%）和 Hyalomma excavatum（6.5%）。蜱虫感染模式显示，55.9%的牛同时感染了 R. microplus 和 H. anatolicum，其次是 R. microplus 和 H. anatolicum 与 H. marginatum（29.3%），然后是 R. microplus、H. anatolicum、H. marginatum 和 H. excavatum（11.2%）。对第二内部转录间隔区（ITS2-）和 16S rRNA 基因片段的测序也证实了 Rhipicephalus microplus 的分子鉴定。ITS-2 的系统发育分析显示，所有序列均聚类在 R. microplus 的单个分支中，而 16S rRNA 核苷酸序列显示，本研究中的 R. microplus 与来自巴基斯坦、中国和印度的其他分离株一起聚类在 A 分支中。高蜱虫感染率表明，需要设计针对蜱虫的战略和综合控制措施，以确保该地区家畜的健康。
