Background

The World Health Organization (WHO) attributes the entirety of malaria infection and transmission in the Democratic Republic of the Congo (DRC) to Plasmodium falciparum, one of the several species of malaria known to infect humans. Recent studies have put forth some evidence that transmission of Plasmodium vivax may also be occurring in the DRC. As interventions and treatments differ between malaria species, it is crucial to maintain the most accurate understanding of malaria species diversity in each region.

Methods

Blood samples were taken from aymptomatic children 0-5 years old living in three regions of the DRC in 2014. For this study, samples were taken from a larger pool of samples, collected as part of a population-based survey in three regions. Plasmodium infection was screened for using nested polymerase chain reaction (PCR) assays and species were confirmed by cloning and DNA sequencing.

Results

Of 336 samples screened by PCR, 62.2% (n=209) initially tested positive for P. falciparum and 14.6% (n=49) initially tested positive for P. vivax. Sanger sequencing was performed on PCR-positive Plasmodium samples to confirm identity of Plasmodium species. Sequencing showed Plasmodium malariae in one blood sample and Plasmodium ovale in another sample. Plasmodium vivax was detected in 12/65 cases (18.5%). Overall, 14/65 sequenced cases (21.5%) were infected with a non-falciparum malaria. 330bp 18s P. vivax DNA sequences were obtained.

Conclusions

This study reveals Plasmodium vivax and other non-falciparum malaria across several regions of the DRC, and enforces the importance of further testing and more precise diagnostics when testing for and treating malaria in the DRC. Here, we find a higher proportion of cases of P. vivax malaria than found in previous studies. This is the most robust DNA sequencing of Plasmodium vivax in the DRC to date.

中文翻译：

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DNA分析揭示了刚果民主共和国的非恶性疟疾。

背景

世界卫生组织（WHO）将整个疟疾在刚果民主共和国（DRC）的感染和传播归因于恶性疟原虫（Plasmodium falciparum）， 恶性疟原虫是已知感染人类的​​几种疟疾之一。最近的研究提出了一些证据，表明间日疟原虫的传播  也可能在DRC中发生。由于疟疾种类之间的干预措施和治疗方法不同，因此至关重要的是要对每个地区的疟疾种类多样性保持最准确的了解。

方法

血液样本取自2014年生活在刚果民主共和国三个地区的0-5岁无症状儿童。在本研究中，样本取自更大的样本池，这是在三个地区进行的基于人口调查的一部分。 使用巢式聚合酶链反应（PCR）分析筛选疟原虫感染，并通过克隆和DNA测序确认物种。

结果

在通过PCR筛选的336个样本中，最初对恶性疟原虫呈阳性的 比例为62.2％（n = 209），而对间日疟原虫呈阳性的比例为 14.6％（n = 49）  。对PCR阳性疟原虫样品进行Sanger测序，以确认疟原虫物种的身份。测序表明 疟原虫 一个血液样本，并在卵形疟原虫另一个样本。在12/65例中检出间日疟原虫（18.5％）。总体而言，有14/65个测序病例（21.5％）感染了非恶性疟疾。获得330bp的18s间日疟原虫DNA序列。

结论

这项研究揭示了在刚果民主共和国几个地区的间日疟原虫和其他非恶性疟疾，并在刚果民主共和国测试和治疗疟疾时加强了进一步测试和更精确诊断的重要性。在这里，我们发现间日疟原虫疟疾病例的比例高于以前的研究。这是迄今为止DRC中间日疟原虫最强大的DNA测序。