Data from: A new malaria agent in African hominids.

Plasmodium falciparum is the major human malaria agent responsible for 200 to 300 million infections and one to three million deaths annually, mainly among African infants. The origin and evolution of this pathogen within the human lineage is still unresolved. A single species, P. reichenowi, which infects chimpanzees, is known to be a close sister lineage of P. falciparum. Here we report the discovery of a new Plasmodium species infecting Hominids. This new species has been isolated in two chimpanzees (Pan troglodytes) kept as pets by villagers in Gabon (Africa). Analysis of its complete mitochondrial genome (5529 nucleotides including Cyt b, Cox I and Cox III genes) reveals an older divergence of this lineage from the clade that includes P. falciparum and P. reichenowi (approximately 21+/-9 Myrs ago using Bayesian methods and considering that the divergence between P. falciparum and P. reichenowi occurred 4 to 7 million years ago as generally considered in the literature). This time frame would be congruent with the radiation of hominoids, suggesting that this Plasmodium lineage might have been present in early hominoids and that they may both have experienced a simultaneous diversification. Investigation of the nuclear genome of this new species will further the understanding of the genetic adaptations of P. falciparum to humans. The risk of transfer and emergence of this new species in humans must be now seriously considered given that it was found in two chimpanzees living in contact with humans and its close relatedness to the most virulent agent of malaria.

恶性疟原虫（Plasmodium falciparum）是引发人类疟疾的主要病原体，每年造成2亿至3亿例感染与100万至300万例死亡，受害者多为非洲婴幼儿。该病原体在人类支系中的起源与演化至今仍未阐明。已知寄生于黑猩猩的里氏疟原虫（P. reichenowi）是恶性疟原虫的近缘姊妹支系。本研究报道了一种新的寄生于人科（Hominids）的疟原虫物种：该新物种分离自非洲加蓬村民作为宠物饲养的两只黑猩猩（Pan troglodytes）体内。对其完整线粒体基因组（全长5529个核苷酸，包含细胞色素b（Cyt b）、Cox I及Cox III基因）的分析显示，该支系与包含恶性疟原虫和里氏疟原虫的演化支的分化时间更早：采用贝叶斯（Bayesian）方法估算，分化时间约为21±9百万年，该估算基于学界普遍认可的恶性疟原虫与里氏疟原虫的分化时间为400万至700万年这一前提。该时间框架与人猿总科（hominoids）的辐射演化时间相吻合，提示该疟原虫支系可能早在早期人猿总科物种中就已存在，二者或经历了协同分化。对该新物种核基因组的研究，将有助于进一步阐明恶性疟原虫对人类宿主的遗传适应性机制。鉴于该新物种发现于与人类密切接触的黑猩猩体内，且与当前致病力最强的疟疾病原体亲缘关系极近，因此必须认真考量其向人类宿主转移并引发新发感染的风险。