Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Box 5, Ithaca, NY 14853, USA.
Vet Parasitol. 2013 Sep 23;196(3-4):538-40. doi: 10.1016/j.vetpar.2013.03.022. Epub 2013 Mar 27.
Many regulatory agencies require that the efficacy of veterinary anthelmintic medications be evaluated by enumerating parasites in treated and untreated animals after necropsy. Current ethical considerations, i.e., the 3 Rs of research, call for the replacement of this method with less invasive techniques that would not require animal sacrifice. This study tested standard gastrointestinal endoscopy as an in vivo method of quantifying the intestinal hookworm, Ancylostoma caninum. Worm counts were compared with those from gold standard necropsy. Thirteen dogs inoculated with third-stage A. caninum larvae underwent endoscopy 4-6 weeks post-infection, just prior to necropsy. Two-thirds of the adult hookworms were located in the middle section of the small intestine that could not be reached for endoscopic examination. Not surprisingly, the total worm counts obtained by endoscopy did not correlate with those from necropsy (R(2)=0.05, p=0.464). One method to increase small intestinal access would be to use specialized balloon or spiral endoscopes developed for this purpose in human gastroenterology. Based on the results of this study, standard endoscopy alone is unsuitable for quantification of A. caninum in the small intestine. Parasites in more accessible sites, such as whipworms in the cecum and colon, might be more appropriate targets for endoscopic counting.
许多监管机构要求通过在解剖后对接受和未接受治疗的动物进行寄生虫计数来评估兽医驱虫药物的疗效。目前的伦理考虑因素，即研究的 3 Rs，呼吁用不会导致动物牺牲的侵入性较小的技术取代这种方法。本研究测试了标准胃肠道内窥镜检查作为一种量化肠道钩虫Ancylostoma caninum 的体内方法。将虫体计数与金标准解剖的结果进行了比较。十三只接种第三阶段 A. caninum 幼虫的狗在感染后 4-6 周进行内窥镜检查，就在解剖之前。三分之二的成年钩虫位于无法进行内窥镜检查的小肠中段。不出所料，内窥镜检查获得的总虫体计数与解剖获得的计数不相关（R²=0.05，p=0.464）。增加小肠进入的一种方法是使用专门为此目的开发的用于人类胃肠病学的气球或螺旋内窥镜。基于这项研究的结果，单独使用标准内窥镜检查不适合定量检测小肠中的 A. caninum。更容易进入的部位的寄生虫，例如盲肠和结肠中的鞭虫，可能更适合内窥镜计数。
