Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, C/Monforte de Lemos 5, 28029, Madrid, Spain.
Network Collaborative Research in Tropical Diseases, RICET, Madrid, Spain.
Malar J. 2018 Sep 17;17(1):333. doi: 10.1186/s12936-018-2481-4.
Malaria in Equatorial Guinea remains a major public health problem. The country is a holo-endemic area with a year-round transmission pattern. In 2016, the prevalence of malaria was 12.09% and malaria caused 15% of deaths among children under 5 years. In the Continental Region, 95.2% of malaria infections were Plasmodium falciparum, 9.5% Plasmodium vivax, and eight cases mixed infection in 2011. The main strategy for malaria control is quick and accurate diagnosis followed by effective treatment. Early and accurate diagnosis of malaria is essential for both effective disease management and malaria surveillance. The quality of malaria diagnosis is important in all settings, as misdiagnosis can result in significant morbidity and mortality. Microscopy and RDTs are the primary choices for diagnosing malaria in the field. However, false-negative results may delay treatment and increase the number of persons capable of infecting mosquitoes in the community. The present study analysed the performance of microscopy and RDTs, the two main techniques used in Equatorial Guinea for the diagnosis of malaria, compared to semi-nested multiplex PCR (SnM-PCR).
A total of 1724 samples tested by microscopy, RDT, and SnM-PCR were analysed. Among the negative samples detected by microscopy, 335 (19.4%) were false negatives. On the other hand, the negative samples detected by RDT, 128 (13.3%) were false negatives based on PCR. This finding is important, especially since it is a group of patients who did not receive antimalarial treatment.
Owing to the high number of false negatives in microscopy, it is necessary to reinforce training in microscopy, the "Gold Standard" in endemic areas. A network of reference centres could potentially support ongoing diagnostic and control efforts made by malaria control programmes in the long term, as the National Centre of Tropical Medicine currently supports the National Programme against Malaria of Equatorial Guinea to perform all of the molecular studies necessary for disease control. Taking into account the results obtained with the RDTs, an exhaustive study of the deletion of the hrp2 gene must be done in EG to help choose the correct RDT for this area.
赤道几内亚的疟疾仍然是一个主要的公共卫生问题。该国是一个全年度流行地区，全年都有传播模式。2016 年，疟疾的患病率为 12.09%，疟疾导致 5 岁以下儿童死亡的比例为 15%。在大陆地区，2011 年疟疾感染中 95.2%为恶性疟原虫，9.5%为间日疟原虫，8 例混合感染。疟疾控制的主要策略是快速准确的诊断，然后进行有效的治疗。疟疾的早期和准确诊断对于有效管理疾病和疟疾监测都是必不可少的。在所有环境中，疟疾诊断的质量都很重要，因为误诊可能导致严重的发病率和死亡率。显微镜检查和 RDT 是现场诊断疟疾的主要选择。然而，假阴性结果可能会延迟治疗并增加社区中能够感染蚊子的人数。本研究分析了显微镜检查和 RDT 这两种在赤道几内亚用于诊断疟疾的主要技术与半巢式多重 PCR（SnM-PCR）的性能。
对通过显微镜检查、RDT 和 SnM-PCR 检测的 1724 个样本进行了分析。在显微镜检查检测到的阴性样本中，有 335 个（19.4%）是假阴性。另一方面，基于 PCR，RDT 检测到的阴性样本中，有 128 个（13.3%）是假阴性。这一发现很重要，尤其是因为这是一组未接受抗疟治疗的患者。
由于显微镜检查的假阴性率很高，因此有必要加强对显微镜检查的培训，这是在流行地区的“金标准”。参考中心网络可能会长期支持疟疾控制计划正在进行的诊断和控制工作，因为国家热带医学中心目前支持赤道几内亚国家疟疾方案进行疾病控制所需的所有分子研究。考虑到 RDT 的结果，必须在赤道几内亚对 hrp2 基因缺失进行详尽的研究，以帮助选择该地区正确的 RDT。
