Department of Tropical Medicine, School of Public Health and Tropical Medicine. Tulane University, New Orleans, LA, United States; Division of Microbiology, Tulane National Primate Research Center, Covington, LA, United States.
Division of Microbiology, Tulane National Primate Research Center, Covington, LA, United States.
Acta Trop. 2020 Dec;212:105557. doi: 10.1016/j.actatropica.2020.105557. Epub 2020 May 29.
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.
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.
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.
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.
世界卫生组织（WHO）将整个刚果民主共和国（DRC）的疟疾感染和传播归因于恶性疟原虫，这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，DRC 也可能存在间日疟原虫的传播。由于干预措施和治疗方法因疟疾种类而异，因此准确了解每个地区的疟疾种类多样性至关重要。
2014 年，从刚果民主共和国三个地区的无症状 0-5 岁儿童身上采集血样。在这项研究中，从更大的样本池中采集了样本，这些样本是作为三个地区基于人群的调查的一部分收集的。使用巢式聚合酶链反应（PCR）检测疟原虫感染，并通过克隆和 DNA 测序确认物种。
在通过 PCR 筛选的 336 个样本中，62.2%（n=209）最初检测到恶性疟原虫阳性，14.6%（n=49）最初检测到间日疟原虫阳性。对 PCR 阳性疟原虫样本进行 Sanger 测序以确认疟原虫种属。测序显示一个血样中存在疟原虫疟疾，另一个血样中存在疟原虫卵形。在 12/65 例（18.5%）中检测到间日疟原虫。总的来说，14/65 测序病例（21.5%）感染了非恶性疟原虫疟疾。获得了 330bp 18s P. vivax DNA 序列。
本研究揭示了刚果民主共和国几个地区存在间日疟原虫和其他非恶性疟原虫疟疾，当在刚果民主共和国检测和治疗疟疾时，加强了进一步检测和更精确诊断的重要性。在这里，我们发现间日疟原虫疟疾的比例高于之前的研究。这是迄今为止刚果民主共和国对间日疟原虫进行的最可靠的 DNA 测序。
