2例输入性卵形疟的实验室检测

Laboratory Detection on Two Cases with Imported Plasmodium ovale Infection

目的比较输入性卵形疟实验室检测方法,分析他们的基因特征。方法分别用吉氏染色镜检、CareStartTM疟疾快速诊断试剂盒和巢式PCR等3种方法。对2例河南省自刚果(布)务工归来的输入性卵形疟病例进行检测,并比较检测结果。对2例外周血中疟原虫的18S rRNA基因进行测序、基因特征和同源性分析。结果2例患者均通过吉氏染色镜检观察到典型的卵形疟原虫形态,巢氏PCR均扩增出与卵形疟预期一致的特异性条带,但CareStartTM疟疾快速诊断试剂盒检测结果均为阴性。对2例外周血中疟原虫的18S rRNA基因测序,获得一条长度均为906 bp的序列,GC含量为35.4%,与已知卵形疟18S rRNA的基因序列(GenBank登录号为AB182492)同源性为99%。结论巢式PCR检测与吉氏染色镜检结果一致,CareStartTM疟疾快速诊断试剂盒检测阴性则不能排除卵形疟原虫感染。

Objective To compare the laboratory tests of the imported Plasmodium ovale infection and analyse the genetic character. Methods After Giemsa staining and microscopy, CareStartTM rapid detection and nested PCR were used to detect two cases with P. ovale infection returning from Congo（Brazzaville） in Henan Province. Sequencing was performed after PCR amplification using the 18S rRNA genus-specific primers. Their genetic characteristics were analyzed and the sequence homology analysis was performed in the NCBI. Results The two cases were confirmed as P. ovale infection by morphological examination microscopically. Amplified bands were produced by 18S rRNA nested PCR, which was the same with P. ovale in size, whereas the results of CareStartTM rapid detection test were all negative. A sequence of 906 bp in length was obtained by sequencing their 18S rRNA genes in which GC accounted for 35.4%, and the sequence showed 99% homology to the corresponding part of the known P. ovale 18S rRNA gene（GenBank accession No. AB182492）. Conclusion Both the nested PCR and microscopy confirm the infection of P. ovale. A negative result of CareStartTM rapid detection can not ruled out the Plasmodium infection.