快速检测试剂条、镜检和PCR在疟疾诊断中的应用研究

Study on the application of RDT,microscopy examination and PCR on malaria

目的采用快速检测试剂条（rapiddiagnostictest，RDT）、镜检及聚合酶链反应（polymerasechainreac-tion，PCR），3种检测方法进行疟原虫检测，比较3种方法在疟疾诊断中的敏感性、特异性，为科学分析检测结果和探究RDT能否在基层替代疟原虫镜检提供依据。方法收集安徽省2012年1月～2013年3月确诊以及疑似病例抗凝血148份，血片148张，采用RDT进行检测，并与镜检法和PCR的结果对比分析其敏感性与特异性。结果148份血样采用RDT、镜检和PCR3种方法检测结果阳性率分别为43．24％、36．49％、37．84％，经配对x2检验RDT阳性率高于镜检和PCR；镜检和PCR均检出2例卵形疟，而RDT结果为阴性；以镜检为标准，对间日疟和恶性疟进行分析得出，RDT的敏感度为100％，特异度87％，阳性预测值81％，阴性预测值100％；以PCR为标准，对间日疟和恶性疟进行分析得出，RDT的灵敏度为100％，特异度89％，阳性预测值84％，阴性预测值100％。3种方法均检出间日疟16例，而对恶性疟分别为RDT检出48例，镜检检出36例，PCR检出38例。结论RDT对间日疟和恶性疟敏感性较高，可以覆盖全部阳性病例，在今后疟疾低流行时期RDT有望取代基层镜检对疟疾进行诊断。

Objective To compare the sensibility, specificity and consistency among microscopic examination, rapid diagnostic test（RDT） and polymerase chain reaction（PCR） in the diagnosis of malaria, and provide the basis for de- ciding whether RDT can replace microscopic examination in county level hospitals. Methods 148 suspected and con- firmed blood samples, and 148 blood smears were collected and detected by microscopic examination, RDT and PCR from January 2012 to March 2013. Then, all the results were compared in pairs. Results A total of 148 samples were tested. The positive rates of RDT, microscopic examination and PCR were 43.24%, 36.49% and 37. 84%, respectively. Two plasmodium ovale were detected by microscopic examination and PCR, but not by RDT. Compared to microscopy, the sen- sitivity of RDT was 100%, specificity 87% ,positive predictive value 81%, negative predictive value 100% ; Compared to PCR, the sensitivity of RDT was 100%, specificity 89%, positive predictive value 84%, negative predictive value 100%. 16 cases diagnosed as plasmodium vivax were detected by all of the three methods. 48 plasmodium falciparum were detected by RDT, 36 plasmodium falciparum were detected by microscopy examination, and 38 detected by PCR. Conclusions The sensitivity and specificity of RDT are very high, and overwhelming majority of p. v and p. f can be detected by RDT. Hence, RDT can totally replace microscopic examination to diagnose malaria in low malaria epidemic period.