Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
PLoS Negl Trop Dis. 2011 Apr 12;5(4):e1036. doi: 10.1371/journal.pntd.0001036.
Sensitive diagnostic tools are required for an accurate assessment of prevalence and intensity of helminth infections in areas undergoing regular deworming, and for monitoring anthelmintic drug efficacy. We compared the diagnostic accuracy of the Kato-Katz and FLOTAC techniques in the frame of a drug efficacy trial.
METHODOLOGY/PRINCIPAL FINDINGS: Stool samples from 343 Zanzibari children were subjected to duplicate Kato-Katz thick smears and the FLOTAC basic technique in a baseline screening in early 2009. The FLOTAC showed a higher sensitivity than the Kato-Katz method for the diagnosis of Trichuris trichiura (95% vs. 88%, p = 0.012) and Ascaris lumbricoides (88% vs. 68%, p = 0.098), but a lower sensitivity for hookworm diagnosis (54% vs. 81%, p = 0.006). Considering the combined results from both methods as 'gold' standard, the prevalences of T. trichiura, hookworm and A. lumbricoides were 71% (95% confidence interval (CI): 66-75%), 22% (95% CI: 17-26%) and 12% (95% CI: 8-15%), respectively. At follow-up, 3-5 weeks after 174 among the 269 re-examined children were administered anthelmintic drugs, we observed cure rates (CRs) against A. lumbricoides, hookworm and T. trichiura of 91% (95% CI: 80-100%), 61% (95% CI: 48-75%) and 41% (95% CI: 34-49%), respectively, when using the Kato-Katz method. FLOTAC revealed lower CRs against A. lumbricoides (83%, 95% CI: 67-98%) and T. trichiura (36%, 95% CI: 29-43%), but a higher CR against hookworm (69%, 95% CI: 57-82%). These differences, however, lacked statistical significance. Considerable differences were observed in the geometric mean fecal egg counts between the two methods with lower egg reduction rates (ERRs) determined by FLOTAC.
CONCLUSION/SIGNIFICANCE: Our results suggest that the FLOTAC technique, following further optimization, might become a viable alternative to the Kato-Katz method for anthelmintic drug efficacy studies and for monitoring and evaluation of deworming programs. The lower CRs and ERRs determined by FLOTAC warrant consideration and could strategically impact future helminth control programs.
在进行常规驱虫的地区，需要敏感的诊断工具来准确评估寄生虫感染的流行率和强度，并监测驱虫药物的疗效。我们在药物疗效试验中比较了加藤厚涂片和 FLOTAC 技术的诊断准确性。
方法/主要发现：2009 年初，343 名桑给巴尔儿童的粪便样本进行了两次加藤厚涂片和 FLOTAC 基础技术的基线筛查。FLOTAC 对诊断鞭虫（95%比 88%，p=0.012）和蛔虫（88%比 68%，p=0.098）的敏感性高于加藤厚涂片法，但对钩虫诊断的敏感性较低（54%比 81%，p=0.006）。考虑到两种方法的综合结果作为“金标准”，鞭虫、钩虫和蛔虫的流行率分别为 71%（95%置信区间（CI）：66-75%）、22%（95% CI：17-26%）和 12%（95% CI：8-15%）。在随访中，在 269 名重新检查的儿童中，有 174 名在 3-5 周后接受了驱虫药物治疗，我们观察到对蛔虫、钩虫和鞭虫的治愈率（CR）分别为 91%（95%CI：80-100%）、61%（95%CI：48-75%）和 41%（95%CI：34-49%），而使用加藤厚涂片法的 CR 分别为 83%（95%CI：67-98%）和 36%（95%CI：29-43%）。然而，这些差异缺乏统计学意义。在两种方法的粪便虫卵计数方面观察到了相当大的差异，FLOTAC 确定的虫卵减少率（ERR）较低。
结论/意义：我们的结果表明，FLOTAC 技术经过进一步优化，可能成为加藤厚涂片法进行驱虫药物疗效研究以及监测和评估驱虫方案的可行替代方法。FLOTAC 确定的较低的 CR 和 ERR 需要考虑，并可能对未来的寄生虫控制计划产生战略影响。
