辽宁省2017年5例输入性卵形疟疾的实验室诊断

Imported oval malaria in Liaoning province, China, in 2017:a laboratory diagnosis of 5 cases

目的实验室鉴定和分析输入性卵形疟疾,比较不同实验室检测方法的结果并分析其基因型别,以避免卵形疟疾的误诊与漏诊。方法分别采用吉氏染色镜检、疟疾快速诊断试验(RDT)和巢式多重PCR 3种方法对辽宁省务工归来的5例输入性卵形疟疾患者进行检测,并比较检测结果。对5例患者外周血中的疟原虫18S r RNA基因进行测序和同源性分析。结果 5例卵形疟疾患者通过吉氏染色镜检均观察到典型的卵形疟原虫形态,疟疾RDT和PCR检测结果均为阳性。对5例外周血中疟原虫的18S rRNA基因进行测序,获得1条长度均为800 bp的序列,通过GenBank比对,与已知卵形疟疾18S r RNA同源性达到99%。结论巢式PCR检测、疟疾RDT和疟疾染色镜检的结果一致,均为卵形疟原虫,需及时加强疟疾流行地区对疟原虫实验室镜检的检测能力水平,联合分子生物学检测技术可大大降低实验室误诊和漏诊。

Objective To compare different laboratory assays for identifying imported oval malaria in laboratories and to analyze the genotypes, and to avoid misdiagnosis and missed diagnosis of oval malaria. Methods Five cases of imported oval malaria returning from labor in Liaoning province, China were diagnosed by three methods: Giemsa staining microscopy, combined Biotech malaria RDT diagnostic kit, and nested PCR, and the results were compared. The 18 S rRNA genes of Plasmodium falciparum in peripheral blood samples from the five cases were subjected to sequencing and homology analysis. Results The morphology of typical P. ovale was observed in all samples by Giemsa staining microscopy. The results of RDT detection and PCR detection of malaria were all positive. The 18 S rRNA gene of Plasmodium falciparum was sequenced and a sequence of 800 bp in length was obtained. The homology of the 18 S rRNA with that in oval malaria was up to 99% by GenBank alignment. Conclusion The results of nested PCR detection, rapid detection, and staining microscopy for oval malaria cases are consistent(P. ovale). It is necessary to promptly strengthen the ability of microscopic examination for Plasmodium in the epidemic areas of malaria, and its combination with molecular biological detection technology can greatly reduce misdiagnosis and missed diagnosis of Plasmodium in laboratories.