Abstract:
Mass drug administration (MDA) of antifilarial drugs is the main strategy for the elimination of lymphatic filariasis (LF). Recent clinical trials indicated that the triple-drug therapy with ivermectin, diethylcarbamazine, and albendazole (IDA) is much more effective against LF than the widely used two-drug combinations (albendazole plus either ivermectin or diethylcarbamazine). For IDA-based MDA, the stop-MDA decision is made based on microfilariae (mf) prevalence in adults. In this study, we assess how the probability of eventually reaching elimination of transmission depends on the critical threshold used in transmission assessment surveys (TAS-es) to define whether transmission was successfully suppressed and triple-drug MDA can be stopped. This analysis focuses on treatment-naive Indian settings. We do this for a range of epidemiological and programmatic contexts, using the established LYMFASIM model for transmission and control of LF. Based on our simulations, a single TAS, one year after the last MDA round, provides limited predictive value of having achieved suppressed transmission, while a higher MDA coverage increases elimination probability, thus leading to a higher predictive value. Every additional TAS, conditional on previous TAS-es being passed with the same threshold, further improves the predictive value for low values of stop-MDA thresholds. An mf prevalence threshold of 0.5% corresponding to TAS-3 results in ≥95% predictive value even when the MDA coverage is relatively low.
摘要:
抗丝虫病药物的批量给药(MDA)是消除淋巴丝虫病(LF)的主要战略。最近的临床试验表明,伊维菌素的三联药物治疗,二乙基卡巴嗪,和阿苯达唑(IDA)比广泛使用的两种药物组合(阿苯达唑加伊维菌素或二乙基卡巴嗪)更有效。对于基于IDA的MDA,停止MDA的决定是根据成人微丝虫(mf)的患病率做出的。在这项研究中,我们评估最终达到传播消除的概率如何取决于传播评估调查(TAS-es)中使用的临界阈值,以确定传播是否被成功抑制以及三联药MDA是否可以被阻止.此分析侧重于天真的印度环境。我们这样做是为了一系列的流行病学和计划背景,利用建立的LYMFASIM模型进行LF的传输和控制。根据我们的模拟,一个TAS,在最后一轮MDA之后的一年,提供了有限的预测值实现抑制传输,而更高的MDA覆盖率增加了消除概率,从而导致更高的预测值。每增加一个TAS,以先前的TAS-es以相同的阈值通过为条件,进一步提高了停止-MDA阈值低值的预测值。即使MDA覆盖率相对较低,对应于TAS-3的mf患病率阈值为0.5%也会导致≥95%的预测值。