Ahmed Ramzan, Devnath Kuldip, Bhowmik Deep, Sharma Indu
Department of Microbiology, Assam University, Silchar, Assam, India.
Indian J Med Microbiol. 2018 Oct-Dec;36(4):541-546. doi: 10.4103/ijmm.IJMM_18_394.
The study aimed to evaluate the diagnostic performance of malaria through microscopy and rapid diagnostic test (RDT) analysis performed locally and the accuracy evaluated by nested polymerase chain reaction (PCR) for diagnosis of Plasmodium falciparum from hotspot regions of North East (NE) India.
One thousand one hundred and seventy-three blood samples were collected for identification of P. falciparum infection using microscopy and RDT analysis. DNA was extracted from whole blood using QIAamp DNA blood mini kit, and nested PCR was performed to confirm P. falciparum for evaluating sensitivity and specificity from various epidemiological surveys and geographical areas of NE India.
Of 1173 symptomatic malaria suspected patients, 15.6% (183/1173) patients were diagnosed as malaria positive by RDT and 67.94% cases (53/78) with microscopy. Of 183 malaria-positive patients, 42.62% (78/183) were diagnosed with P. falciparum and 84.61% (66/78) further confirmed to be P. falciparum positive by nested PCR. High sensitivity (97.9%) and low specificity (2.03%) of the RDT and high sensitivity (99.1%) and low specificity (0.9%) in microscopy against nested PCR results was statistically significant (P < 0.05). Epidemiological comparisons expressed highest incidences in Manipur (51.11%) followed by Meghalaya (48.93%) and Assam (35.16%). Overall incidence rate among the genders was observed to be higher in males than in females.
Our findings suggest that PCR, RDT and microscopy can potentially determine hotspots at moderate transmission intensities, but PCR testing has a diagnostic advantage as transmission intensity falls. Therefore, malaria control programs should consider PCR testing when the prevalence of infection is low.
本研究旨在通过在当地进行的显微镜检查和快速诊断检测（RDT）分析来评估疟疾的诊断性能，并通过巢式聚合酶链反应（PCR）评估印度东北部（NE）热点地区恶性疟原虫诊断的准确性。
采集了1173份血样，使用显微镜检查和RDT分析来鉴定恶性疟原虫感染。使用QIAamp DNA血液微型试剂盒从全血中提取DNA，并进行巢式PCR以确认恶性疟原虫，从而评估印度东北部不同流行病学调查和地理区域的敏感性和特异性。
在1173例有症状的疑似疟疾患者中，RDT诊断为疟疾阳性的患者占15.6%（183/1173），显微镜检查确诊的病例占67.94%（53/78）。在183例疟疾阳性患者中，42.62%（78/183）被诊断为恶性疟原虫感染，84.61%（66/78）通过巢式PCR进一步确认为恶性疟原虫阳性。RDT的高敏感性（97.9%）和低特异性（2.03%）以及显微镜检查相对于巢式PCR结果的高敏感性（99.1%）和低特异性（0.9%）具有统计学意义（P < 0.05）。流行病学比较显示，曼尼普尔邦的发病率最高（51.11%），其次是梅加拉亚邦（48.93%）和阿萨姆邦（35.16%）。总体而言，男性的发病率高于女性。
我们的研究结果表明，PCR、RDT和显微镜检查在中等传播强度下可能有助于确定热点地区，但随着传播强度降低，PCR检测具有诊断优势。因此，当感染率较低时，疟疾控制项目应考虑采用PCR检测。
