Ayogu E E, Ukwe C V, Nna E O
Department of Clinical Pharmacy and Pharmacy Management, Faculty of Pharmaceutical Sciences, University of Nigeria; Pharmacy Unit, District Hospital Nsukka, Ministry of Health, Nsukka, Nigeria.
Department of Clinical Pharmacy and Pharmacy Management, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Nigeria.
J Postgrad Med. 2016 Jul-Sep;62(3):150-6. doi: 10.4103/0022-3859.183167.
Current malaria control strategies are based on early diagnosis and appropriate treatment of malaria cases. The study aimed at comparing the performance of blood film microscopy and rapid diagnostic test (RDT) in Plasmodium falciparum detection in patients ≥6 years of age.
A total of 154 consecutive pyretic patients aged 6-62 years were enrolled, sampled, and tested for malaria using RDT (first response) and microscopy by Giemsa staining. Genomic DNA was extracted after saponin hemolysis and nested polymerase chain reaction (PCR) was used to detect Plasmodium falciparum. The endpoints were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).
Of the 154 patients, 80 (51.9%) had fever of ≥37.5°C. 106 (68.8%) were positive by First response® , 132 (85.7%) by microscopy, and 121 (78.6%) by PCR. The sensitivity, specificity, PPV, and NPV of first response compared to microscopic method were 82.2%, 100.0%, 100.0%, and 34.3%, respectively, while it was 75.4%, 75.0%, 95.3%, and 31.2%, respectively, when compared to PCR. The sensitivity, specificity, PPV, and NPV of the microscopic method compared to PCR were 92.3%, 50.0%, 90.91%, and 54.5%, respectively. There was a significant difference in the performance of RDT and film microscopy methods (P ≤ 0.05).
Microscopy performed better and is more reliable than first response (RDT) in areas with low parasite density among patients ≥6 years of age. Rapid diagnostic tests could be useful in aareas with high parasite density as an alternative to smear microscopy.
当前的疟疾控制策略基于对疟疾病例的早期诊断和适当治疗。本研究旨在比较血涂片显微镜检查和快速诊断检测(RDT)在≥6岁患者中检测恶性疟原虫的性能。
共纳入154例年龄在6至62岁之间的连续发热患者,进行采样,并使用RDT(第一反应)和吉姆萨染色显微镜检查法检测疟疾。皂素溶血后提取基因组DNA,采用巢式聚合酶链反应(PCR)检测恶性疟原虫。观察指标为敏感性、特异性、阳性预测值(PPV)和阴性预测值(NPV)。
154例患者中,80例(51.9%)体温≥37.5°C。第一反应检测法阳性106例(68.8%),显微镜检查法阳性132例(85.7%),PCR检测法阳性121例(78.6%)。与显微镜检查法相比,第一反应检测法的敏感性、特异性、PPV和NPV分别为82.2%、100.0%、100.0%和34.3%;与PCR检测法相比,分别为75.4%、75.0%、95.3%和31.2%。与PCR检测法相比,显微镜检查法的敏感性、特异性、PPV和NPV分别为92.3%、50.0%、90.91%和54.5%。RDT和血涂片显微镜检查法的性能存在显著差异(P≤0.05)。
在≥6岁且疟原虫密度较低的患者中,显微镜检查法比第一反应检测法(RDT)表现更好且更可靠。在疟原虫密度较高的地区,快速诊断检测可作为涂片显微镜检查的替代方法。