Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
Department of Global Health, Boston University School of Public Health, Boston, MA, USA.
Sci Rep. 2021 Mar 25;11(1):6905. doi: 10.1038/s41598-021-86450-5.
In areas where malaria remains entrenched, novel transmission-reducing interventions are essential for malaria elimination. We report the impact screening-and-treatment of asymptomatic Malawian schoolchildren (n = 364 in the rainy season and 341 in the dry season) had on gametocyte-the parasite stage responsible for human-to-mosquito transmission-carriage. We used concomitant household-based surveys to predict the potential reduction in transmission in the surrounding community. Among 253 students with P. falciparum infections at screening, 179 (71%) had infections containing gametocytes detected by Pfs25 qRT-PCR. 84% of gametocyte-containing infections were detected by malaria rapid diagnostic test. While the gametocyte prevalence remained constant in untreated children, treatment with artemether-lumefantrine reduced the gametocyte prevalence (p < 0.0001) from 51.8 to 9.7% and geometric mean gametocyte density (p = 0.008) from 0.52 to 0.05 gametocytes/microliter. In community surveys, 46% of all gametocyte-containing infections were in school-age children, who comprised only 35% of the population. Based on these estimates six weeks after the intervention, the gametocyte burden in the community could be reduced by 25-55% depending on the season and the measure used to characterize gametocyte carriage. Thus, school-based interventions to treat asymptomatic infections may be a high-yield approach to not only improve the health of schoolchildren, but also decrease malaria transmission.
在疟疾仍然严重的地区，新型的降低传播干预措施对于消除疟疾至关重要。我们报告了对无症状马拉维学童（雨季 364 人，旱季 341 人）进行筛查和治疗对配子体（负责寄生虫向蚊子传播的阶段）携带的影响。我们利用同时进行的家庭为基础的调查来预测周围社区潜在的传播减少。在筛查时患有恶性疟原虫感染的 253 名学生中，有 179 名（71%）感染含有通过 PfS25 qRT-PCR 检测到的配子体。84%的含配子体感染通过疟疾快速诊断检测到。虽然未治疗儿童的配子体患病率保持不变，但青蒿琥酯-咯萘啶治疗降低了配子体患病率（p<0.0001），从 51.8%降至 9.7%，几何平均配子体密度（p=0.008）从 0.52 降至 0.05 配子体/微升。在社区调查中，所有含配子体感染的 46%发生在学龄儿童中，而学龄儿童仅占人口的 35%。根据干预后六周的这些估计，社区中的配子体负担可以减少 25-55%，具体取决于季节和用于描述配子体携带的措施。因此，针对无症状感染进行的以学校为基础的干预措施可能是一种高收益的方法，不仅可以改善学童的健康状况，还可以降低疟疾传播。
