Mavundela Songezo, Dzemo William Diymba, Thekisoe Oriel
Departmanent of Biological and Environmental Sciences, Walter Sisulu University, Private Bag X1, Mthatha, 5117, South Africa.
Unit for Environmental Sciences and Management, North-West University, Potchefstroom, 2531, South Africa.
Parasitol Res. 2025 Aug 5;124(8):86. doi: 10.1007/s00436-025-08532-x.
Anthelmintic drugs are readily accessible to farmers and have been widely used to control gastrointestinal nematode (GIN) infections in communally reared sheep in the Eastern Cape Province (ECP), South Africa. Indiscriminate and prolonged use of these drugs has inevitably contributed to the selection of resistant GIN populations. This study aimed to assess the anthelmintic resistance status of GINs in communally reared sheep farms in King Sabata Dalindyebo Local Municipality, ECP. A semi-structured questionnaire was used to collect data on farm characteristics and helminth control practices. Faecal egg count reduction tests were performed on 259 lambs selected from eight communal farms. Lambs with egg per gram count > 150 were treated with anthelmintics (co-formulation of albendazole + closantel, and levamisole) currently used on the farms as well as an alternative anthelmintic from a different drug class (ivermectin, and a co-formulation of levamisole + praziquantel). Several suboptimal helminth control practices were identified that may have compromised the accurate administration of anthelmintics and effective management of deworming. These include the advanced age (> 65 years) of farmers: failure to weigh sheep prior to drug administration, use of syringes (5 ml/10 ml) instead of drench guns, and absence of a drenching and shifting approach. Helminths eggs from the genera Moniezia, Strongyloides, Trichuris, and Haemonchus were identified in both pre-and post-treatment faecal samples. Coprological culture of post-treatment samples, followed by morphological and molecular identification of larvae, confirmed the presence of Haemonchus contortus. This GIN species exhibited resistance to all the anthelmintic formulations assessed in this study. These findings highlight the urgent need for improved management strategies to mitigate resistance and promote sustainable worm control in communal sheep farming areas of ECP.
驱虫药物很容易被农民获取，并且已被广泛用于控制南非东开普省（ECP） communal饲养绵羊的胃肠道线虫（GIN）感染。这些药物的滥用和长期使用不可避免地导致了耐药GIN种群的产生。本研究旨在评估ECP国王萨巴塔·达林德耶博地方市 communal饲养绵羊农场中GIN的驱虫抗药状况。使用半结构化问卷收集有关农场特征和蠕虫控制措施的数据。对从八个 communal农场挑选的259只羔羊进行了粪便虫卵计数减少试验。每克虫卵数>150的羔羊用农场目前使用的驱虫药（阿苯达唑+氯氰碘柳胺复方制剂和左旋咪唑）以及来自不同药物类别的替代驱虫药（伊维菌素和左旋咪唑+吡喹酮复方制剂）进行治疗。确定了几种不理想的蠕虫控制措施，这些措施可能会影响驱虫药的准确施用和驱虫的有效管理。这些措施包括农民年龄偏大（>65岁）、给药前未对绵羊称重、使用注射器（5毫升/10毫升）而非灌药枪以及缺乏灌药和转移方法。在治疗前和治疗后的粪便样本中均鉴定出莫尼茨绦虫属、类圆线虫属、毛首线虫属和血矛线虫属的蠕虫卵。对治疗后样本进行粪便培养，随后对幼虫进行形态学和分子鉴定，证实存在捻转血矛线虫。这种GIN物种对本研究评估的所有驱虫药制剂均表现出抗性。这些发现凸显了迫切需要改进管理策略，以减轻抗性并促进ECP communal绵羊养殖区的可持续蠕虫控制。
