Eisler M C, Maruta J, Nqindi J, Connor R J, Ushewokunze-Obatolu U, Holmes P H, Peregrine A S
University of Glasgow Veterinary School, UK.
Trop Med Int Health. 1996 Aug;1(4):535-41. doi: 10.1046/j.1365-3156.1996.d01-87.x.
An experiment was carried out to determine the concentrations of the trypanocidal drug isometamidium chloride in the sera of cattle maintained under a chemoprophylactic regimen at Rekomitjie, Zimbabwe, an area of high tsetse challenge in the Zimbabwe valley. In February 1993, 24 cattle at this site were treated intramuscularly with isometamidium chloride at a dose of 1.0 mg/kg body weight. Thereafter all animals were monitored regularly for 6 months for the presence of trypanosomes and sera were collected to determine the concentrations of isometamidium using an ELISA. Isometamidium treated cattle appeared to be protected against trypanosome infections for at least 18 weeks following treatment. Thereafter, three trypanosome infections were detected, between 20 and 22 weeks following treatment. In contrast, in 18 untreated control cattle at the same site, 9 trypanosome infections were detected over the first 18 weeks of the experiment. Quantification of the isometamidium concentration in sera from the drug treated cattle indicated that the apparent half-life of isometamidium in these animals was 23 days. This was similar to the half-life observed previously in cattle treated under laboratory conditions. The isometamidium ELISA was shown to be capable of quantifying drug levels in 20 out of 23 cattle for at least 70 days after treatment. There was no evidence of drug resistant trypanosomes at this site.
在津巴布韦里科米捷开展了一项实验，以测定在采采蝇肆虐的津巴布韦河谷地区接受化学预防方案的牛血清中杀锥虫药物氯异噁脒的浓度。1993年2月，该地点的24头牛以1.0毫克/千克体重的剂量肌肉注射氯异噁脒。此后，对所有动物进行了6个月的定期监测，以检查是否存在锥虫，并采集血清，用酶联免疫吸附测定法（ELISA）测定氯异噁脒的浓度。经氯异噁脒治疗的牛在治疗后至少18周似乎受到保护，免受锥虫感染。此后，在治疗后20至22周之间检测到3例锥虫感染。相比之下，在同一地点的18头未经治疗的对照牛中，在实验的前18周检测到9例锥虫感染。对经药物治疗的牛血清中氯异噁脒浓度的定量分析表明，氯异噁脒在这些动物体内的表观半衰期为23天。这与之前在实验室条件下治疗的牛中观察到的半衰期相似。氯异噁脒酶联免疫吸附测定法显示，在治疗后至少70天内，能够对23头牛中的20头的药物水平进行定量。该地点没有耐药锥虫的证据。
