We collected repeated Kato-Katz egg counts from 210 school-aged children and scored POC-CCA tests according to the manufacturer\'s guidelines (referred to from here as POC-CCA+) and the externally developed G score. We used hidden Markov models parameterized with Kato-Katz; Kato-Katz and POC-CCA+; and Kato-Katz and G-Scores, inferring latent clearance and reinfection probabilities at four timepoints over six-months through a more formal statistical reconciliation of these diagnostics than previously conducted. Our approach required minimal but robust assumptions regarding trace interpretations.
Antigen-based models estimated higher infection prevalence across all timepoints compared with the Kato-Katz model, corresponding to lower clearance and higher reinfection estimates. Specifically, pre-treatment prevalence estimates were 85% (Kato-Katz; 95% CI: 79%-92%), 99% (POC-CCA+; 97%-100%) and 98% (G-Score; 95%-100%). Post-treatment, 93% (Kato-Katz; 88%-96%), 72% (POC-CCA+; 64%-79%) and 65% (G-Score; 57%-73%) of those infected were estimated to clear infection. Of those who cleared infection, 35% (Kato-Katz; 27%-42%), 51% (POC-CCA+; 41%-62%) and 44% (G-Score; 33%-55%) were estimated to have been reinfected by 9-weeks.
Treatment impact was shorter-lived than Kato-Katz-based estimates alone suggested, with lower clearance and rapid reinfection. At 3 weeks after treatment, longer-term clearance dynamics are captured. At 9 weeks after treatment, reinfection was captured, but failed clearance could not be distinguished from rapid reinfection. Therefore, frequent sampling is required to understand these important epidemiological dynamics.
我们从210名学龄儿童中收集了重复的Kato-Katz鸡蛋计数,并根据制造商的指南(此处称为POC-CCA+)和外部开发的G评分对POC-CCA测试进行了评分。我们使用了用Kato-Katz、Kato-Katz和POC-CCA+以及Kato-Katz和G分数参数化的隐马尔可夫模型,通过对这些诊断进行比以前更正式的统计核对,推断六个月内四个时间点的潜伏清除和再感染概率。我们的方法需要关于痕迹解释的最小但可靠的假设。
与Kato-Katz模型相比,基于抗原的模型估计所有时间点的感染率更高,对应于较低的清除率和较高的再感染估计。具体来说,治疗前的患病率估计为85%(Kato-Katz;95%CI:79%-92%),99%(POC-CCA+;97%-100%)和98%(G评分;95%-100%)。后处理,93%(加藤-卡茨;88%-96%),估计有72%(POC-CCA;64%-79%)和65%(G评分;57%-73%)的感染者可以清除感染。在那些清除感染的人中,35%(加藤-卡茨;27%-42%),估计有51%(POC-CCA;41%-62%)和44%(G评分;33%-55%)在9周内再次感染。
治疗效果比Kato-Katz单独估计的时间短,具有较低的清除率和快速的再感染。治疗后3周,较长期的清除动态被捕获。治疗后9周,再次感染被捕获,但清除失败无法与快速再感染区分开来。因此,需要频繁的采样来了解这些重要的流行病学动态。