How effective is school-based deworming for the community-wide control of soil-transmitted helminths?
How effective is school-based deworming for the community-wide control of soil-transmitted helminths?
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DOI：
10.1371/journal.pntd.0002027
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发表时间：
2013
影响因子：
3.8
通讯作者：
Hollingsworth TD
中科院分区：
文献类型：
--
作者：
Anderson RM;Truscott JE;Pullan RL;Brooker SJ;Hollingsworth TD
《关于被忽视热带病的伦敦宣言》部分基于世界卫生组织新的路线图，该路线图旨在“维持、扩大和扩大药物获取规划，以确保到2020年提供必要的药物和其他干预措施，以帮助控制疾病”。来自制药业的大量药品捐赠是实现这一目标的支柱，特别是对土壤传播的蠕虫（STHs），这就提出了如何最好地利用这些资源的问题。针对STHs的驱虫通常针对学龄儿童，因为他们患病的风险最大，而且它具有显著的成本效益。然而，以学校为基础的驱虫对更广泛社区传播的影响仍不清楚。我们首先利用人口统计学、学校入学率和来自所有年龄段的特定年龄感染强度（蠕虫或虫卵）的少数示例设置的数据来估计以学校为基础的驱虫所针对的寄生虫比例。我们还使用传播模型来研究这种覆盖对不同混合情况下传播的潜在影响。在示例设置中，小于30%的人口年龄在5至15岁之间。将这一人口统计数据与感染年龄强度概况相结合，我们估计，在一个环境中，学龄儿童产出的钩虫卵只有15%，而在另一个环境中，他们体内的蛔虫高达50%（在我们的例子中，寄生虫的比例最高）。此外，据估计，这些儿童中有40-70%入学。这些估计表明，虽然以学校为基础的规划有许多重要的好处，但以学校为基础的驱虫所针对的感染阶段的比例可能有限，特别是在钩虫占主导地位的地方。我们讨论了一系列情况下传播的后果，包括儿童感染阶段比成人感染阶段更有可能传播的情况。用于治疗土壤传播蠕虫（STHs，肠道蠕虫）的大量药物捐赠意味着更多学龄儿童将得到治疗，从而改善他们的福祉和发展。这些儿童将不得不反复接受治疗，因为在不改善个人卫生和环境卫生的情况下，环境污染将导致再次感染。对学龄儿童的反复治疗可能有降低整个社区感染水平的额外好处。这将在一定程度上取决于学龄儿童所携带的蠕虫总数或所产卵的比例，这是学龄儿童受感染程度和社区中有多少学龄儿童的产物。在一种情况下，学龄儿童只产出15%的钩虫卵，而在另一种情况下，他们却孕育了多达50%的蛔虫。因此，虽然以学校为基础的规划可能具有重要的健康效益，但除非学龄儿童过度促成感染，否则社区一级对传播的影响可能有限。我们使用数学模型表明，如果儿童比成人所处的环境提供更多的感染阶段，那么治疗儿童导致的传播减少将会更大，但可能仍然有限。
The London Declaration on neglected tropical diseases was based in part on a new World Health Organization roadmap to “sustain, expand and extend drug access programmes to ensure the necessary supply of drugs and other interventions to help control by 2020”. Large drug donations from the pharmaceutical industry form the backbone to this aim, especially for soil-transmitted helminths (STHs) raising the question of how best to use these resources. Deworming for STHs is often targeted at school children because they are at greatest risk of morbidity and because it is remarkably cost-effective. However, the impact of school-based deworming on transmission in the wider community remains unclear. We first estimate the proportion of parasites targeted by school-based deworming using demography, school enrolment, and data from a small number of example settings where age-specific intensity of infection (either worms or eggs) has been measured for all ages. We also use transmission models to investigate the potential impact of this coverage on transmission for different mixing scenarios. In the example settings <30% of the population are 5 to <15 years old. Combining this demography with the infection age-intensity profile we estimate that in one setting school children output as little as 15% of hookworm eggs, whereas in another setting they harbour up to 50% of Ascaris lumbricoides worms (the highest proportion of parasites for our examples). In addition, it is estimated that from 40–70% of these children are enrolled at school. These estimates suggest that, whilst school-based programmes have many important benefits, the proportion of infective stages targeted by school-based deworming may be limited, particularly where hookworm predominates. We discuss the consequences for transmission for a range of scenarios, including when infective stages deposited by children are more likely to contribute to transmission than those from adults. Large donations of drugs to treat soil-transmitted helminths (STHs, intestinal worms) means that many more school-aged children will be treated, improving their well-being and development. These children will have to be repeatedly treated since reinfection will occur due to contaminated environments in the absence of improvements in hygiene and sanitation. Repeated treatment of school-aged children may have the added benefit of reductions in levels of infection for the whole community. This will in part be determined by the proportion of the total worms harboured or eggs output by school-aged children, a product of how heavily infected school-aged children are and how many school-aged children there are in the community. In one setting school-aged children output as little as 15% of hookworm eggs whereas in another setting they harbour up to 50% of roundworms. Thus, whilst school-based programmes may have important health benefits, the community-level impact on transmission could be limited unless school-aged children over-contribute to infection. We use mathematical models to show that if children contribute more infective stages to the environment which adults are exposed to than adults do, the reductions in transmission resulting from treating children will be larger, but may still be limited.
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影响因子：
3.2
作者：
Brooker, Simon;Kabatereine, Narcis B.;Devlin, Nancy
通讯作者：
Devlin, Nancy
DOI：
10.1016/0035-9203(92)90448-l
发表时间：
1992-01-01
影响因子：
2.2
作者：
BRADLEY, M;CHANDIWANA, SK;MEDLEY, GF
通讯作者：
MEDLEY, GF
影响因子：
2.7
作者：
ANSCOMBE, FJ
通讯作者：
ANSCOMBE, FJ
影响因子：
2.4
作者：
ASAOLU, SO;HOLLAND, CV;CROMPTON, DWT
通讯作者：
CROMPTON, DWT
影响因子：
2.4
作者：
Bourke CD;Maizels RM;Mutapi F
通讯作者：
Mutapi F