Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
Exeins Health Initiative, Jakarta, Indonesia.
Sci Rep. 2023 Nov 27;13(1):20788. doi: 10.1038/s41598-023-47889-w.
Ethiopia has the greatest burden of Plasmodium vivax in Africa, but little is known about the epidemiological landscape of parasites across the country. We analysed the genomic diversity of 137 P. vivax isolates collected nine Ethiopian districts from 2012 to 2016. Signatures of selection were detected by cross-country comparisons with isolates from Thailand (n = 104) and Indonesia (n = 111), representing regions with low and high chloroquine resistance respectively. 26% (35/137) of Ethiopian infections were polyclonal, and 48.5% (17/35) of these comprised highly related clones (within-host identity-by-descent > 25%), indicating frequent co-transmission and superinfection. Parasite gene flow between districts could not be explained entirely by geographic distance, with economic and cultural factors hypothesised to have an impact on connectivity. Amplification of the duffy binding protein gene (pvdbp1) was prevalent across all districts (16-75%). Cross-population haplotype homozygosity revealed positive selection in a region proximal to the putative chloroquine resistance transporter gene (pvcrt-o). An S25P variant in amino acid transporter 1 (pvaat1), whose homologue has recently been implicated in P. falciparum chloroquine resistance evolution, was prevalent in Ethiopia (96%) but not Thailand or Indonesia (35-53%). The genomic architecture in Ethiopia highlights circulating variants of potential public health concern in an endemic setting with evidence of stable transmission.
埃塞俄比亚是非洲间日疟原虫负担最大的国家，但该国各地寄生虫的流行病学特征却知之甚少。我们分析了 2012 年至 2016 年期间从埃塞俄比亚九个地区采集的 137 株间日疟原虫分离株的基因组多样性。通过与来自泰国（n=104）和印度尼西亚（n=111）的分离株进行跨国比较，检测到了选择的特征，这两个地区分别代表低和高氯喹耐药性的地区。26%（35/137）的埃塞俄比亚感染呈多克隆性，其中 48.5%（17/35）由高度相关的克隆组成（宿主内同源性>25%），表明经常发生共同传播和超感染。地区间寄生虫基因流不能完全用地理距离来解释，经济和文化因素被假设对连通性有影响。所有地区（16-75%）都普遍扩增了杜菲结合蛋白基因（pvdbp1）。跨人群单倍型同质性显示，在假定的氯喹耐药转运蛋白基因（pvcrt-o）附近的一个区域存在正选择。在氨基酸转运蛋白 1（pvaat1）中的一个 S25P 变体在埃塞俄比亚（96%）很常见，但在泰国或印度尼西亚（35-53%）则不常见。该基因组结构突显了在一个流行地区存在具有潜在公共卫生关注的循环变异体，并存在稳定传播的证据。
