Coleman Russell E, Sattabongkot Jetsumon, Promstaporm Sommai, Maneechai Nongnuj, Tippayachai Bousaraporn, Kengluecha Ampornpan, Rachapaew Nattawan, Zollner Gabriela, Miller Robert Scott, Vaughan Jefferson A, Thimasarn Krongtong, Khuntirat Benjawan
Departments of Entomology and Immunology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
Malar J. 2006 Dec 14;5:121. doi: 10.1186/1475-2875-5-121.
The main objective of this study was to compare the performance of nested PCR with expert microscopy as a means of detecting Plasmodium parasites during active malaria surveillance in western Thailand.
The study was performed from May 2000 to April 2002 in the village of Kong Mong Tha, located in western Thailand. Plasmodium vivax (PV) and Plasmodium falciparum (PF) are the predominant parasite species in this village, followed by Plasmodium malariae (PM) and Plasmodium ovale (PO). Each month, fingerprick blood samples were taken from each participating individual and used to prepare thick and thin blood films and for PCR analysis.
PCR was sensitive (96%) and specific (98%) for malaria at parasite densities > or = 500/microl; however, only 18% (47/269) of P. falciparum- and 5% (20/390) of P. vivax-positive films had parasite densities this high. Performance of PCR decreased markedly at parasite densities <500/microl, with sensitivity of only 20% for P. falciparum and 24% for P. vivax at densities <100 parasites/microl.
Although PCR performance appeared poor when compared to microscopy, data indicated that the discrepancy between the two methods resulted from poor performance of microscopy at low parasite densities rather than poor performance of PCR. These data are not unusual when the diagnostic method being evaluated is more sensitive than the reference method. PCR appears to be a useful method for detecting Plasmodium parasites during active malaria surveillance in Thailand.
本研究的主要目的是比较巢式聚合酶链反应（PCR）与专家显微镜检查在泰国西部疟疾主动监测期间检测疟原虫的性能。
该研究于2000年5月至2002年4月在泰国西部的孔蒙塔村进行。间日疟原虫（PV）和恶性疟原虫（PF）是该村的主要疟原虫种类，其次是三日疟原虫（PM）和卵形疟原虫（PO）。每月从每个参与个体采集指尖血样，用于制备厚血膜和薄血膜以及进行PCR分析。
对于寄生虫密度≥500/微升的疟疾，PCR的敏感性为96%，特异性为98%；然而，仅18%（47/269）的恶性疟原虫阳性血膜和5%（20/390）的间日疟原虫阳性血膜具有如此高的寄生虫密度。当寄生虫密度<500/微升时，PCR的性能显著下降，在寄生虫密度<100个/微升时，恶性疟原虫的敏感性仅为20%，间日疟原虫的敏感性为24%。
尽管与显微镜检查相比，PCR的性能似乎较差，但数据表明两种方法之间的差异是由于显微镜检查在低寄生虫密度下性能不佳，而非PCR性能不佳。当所评估的诊断方法比参考方法更敏感时，这些数据并不罕见。在泰国疟疾主动监测期间，PCR似乎是一种检测疟原虫的有用方法。
