PDF(Pubmed)
Abstract：
The World Health Organization has recommended the application of mass drug administration (MDA) in treating high prevalence neglected tropical diseases such as soil-transmitted helminths (STHs), schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. MDA-which is safe, effective and inexpensive-has been widely applied to eliminate or interrupt the transmission of STHs in particular and has been offered to people in endemic regions without requiring individual diagnosis. We propose two mathematical models to investigate the impact of MDA on the mean number of worms in both treated and untreated human subpopulations. By varying the efficay of drugs, initial conditions of the models, coverage and frequency of MDA (both annual and biannual), we examine the dynamic behaviour of both models and the possibility of interruption of transmission. Both models predict that the interruption of transmission is possible if the drug efficacy is sufficiently high, but STH infection remains endemic if the drug efficacy is sufficiently low. In between these two critical values, the two models produce different predictions. By applying an additional round of biannual and annual MDA, we find that interruption of transmission is likely to happen in both cases with lower drug efficacy. In order to interrupt the transmission of STH or eliminate the infection efficiently and effectively, it is crucial to identify the appropriate efficacy of drug, coverage, frequency, timing and number of rounds of MDA.
摘要：
世界卫生组织建议应用大规模药物管理（MDA）治疗高患病率被忽视的热带疾病，如土壤传播的蠕虫（STHs），血吸虫病,淋巴丝虫病，盘尾丝虫病和沙眼。MDA-这是安全的，有效且廉价-已广泛应用于消除或中断特别是STH的传播，并已提供给流行地区的人们，而无需单独诊断。我们提出了两个数学模型来研究MDA对处理和未处理的人类亚群中蠕虫平均数量的影响。通过改变药物的功效，模型的初始条件，MDA的覆盖率和频率(每年和每年两次)，我们检查了两个模型的动态行为和传输中断的可能性。两种模型都预测，如果药物疗效足够高，传播的中断是可能的，但如果药物疗效足够低，STH感染仍然是地方性的。在这两个临界值之间，这两个模型产生不同的预测。通过再应用一轮每半年和每年的MDA，我们发现，在两种药物疗效较低的情况下，传播中断都可能发生。为了有效地阻断STH的传播或消除感染，确定药物的适当功效至关重要，覆盖范围，频率,MDA的时间和轮数。
