Lo Eugenia, Lam Nancy, Hemming-Schroeder Elizabeth, Nguyen Jennifer, Zhou Guofa, Lee Ming-Chieh, Yang Zhaoqing, Cui Liwang, Yan Guiyun
Program in Public Health, University of California-Irvine.
Department of Pathogen Biology and Immunology, Kunming Medical University, China.
J Infect Dis. 2017 Dec 5;216(10):1254-1263. doi: 10.1093/infdis/jix106.
In Myanmar, civil unrest and the establishment of internally displaced person (IDP) settlements along the Myanmar-China border have impacted malaria transmission.
Microsatellite markers were used to examine source-sink dynamics for Plasmodium vivax between IDP settlements and surrounding villages in the border region. Genotypic structure and diversity were compared across the 3 years following the establishment of IDP settlements, to infer demographic history. We investigated whether human migration and landscape heterogeneity contributed to P. vivax transmission.
P. vivax from IDP settlements and local communities consistently exhibited high genetic diversity within populations but low polyclonality within individuals. No apparent genetic structure was observed among populations and years. P. vivax genotypes in China were similar to those in Myanmar, and parasite introduction was unidirectional. Landscape factors, including distance, elevation, and land cover, do not appear to impede parasite gene flow.
The admixture of P. vivax genotypes suggested that parasite gene flow via human movement contributes to the spread of malaria both locally in Myanmar and across the international border. Our genetic findings highlight the presence of large P. vivax gene reservoirs that can sustain transmission. Thus, it is important to reinforce and improve existing control efforts along border areas.
在缅甸，内乱以及沿缅中边境建立的境内流离失所者（IDP）定居点对疟疾传播产生了影响。
利用微卫星标记研究边境地区IDP定居点与周边村庄间间日疟原虫的源 - 汇动态。比较IDP定居点建立后的3年里的基因型结构和多样性，以推断人口统计学历史。我们调查了人类迁移和景观异质性是否促成了间日疟原虫的传播。
来自IDP定居点和当地社区的间日疟原虫在群体内始终表现出高遗传多样性，但个体内多克隆性低。在群体和年份之间未观察到明显的遗传结构。中国的间日疟原虫基因型与缅甸的相似，且寄生虫引入是单向的。包括距离、海拔和土地覆盖在内的景观因素似乎并未阻碍寄生虫基因流动。
间日疟原虫基因型的混合表明，通过人类流动的寄生虫基因流动促成了疟疾在缅甸当地以及跨境的传播。我们的遗传学研究结果突出了存在可维持传播的大型间日疟原虫基因库。因此，加强和改善边境地区现有的防控措施很重要。
