寄生虫学检测在成人输入性间日疟原虫疟疾中的敏感性及化学预防和发作类型的影响。

Sensitivity of parasitological tests in imported Plasmodium vivax malaria in adults and impact of chemoprophylaxis and attack type.

机构信息

Service de Biologie Médicale.

出版信息

J Travel Med. 2014 May-Jun;21(3):195-200. doi: 10.1111/jtm.12116. Epub 2014 Mar 14.

DOI:10.1111/jtm.12116

PMID:24629014

Abstract

BACKGROUND

Plasmodium vivax is the second most common species among cases of imported malaria diagnosed in Europe. The objective of this study is to describe the sensitivity of the parasitological tests in imported P. vivax malaria, and the impact of chemoprophylaxis and attack type (primary infection or relapse).

METHODS

A retrospective study included the imported vivax malaria cases admitted in a French military hospital between 2001 and 2013. The reference diagnosis method was microscopy corrected by polymerase chain reaction (PCR). Thin and thick blood films examination, quantitative buffy coat (QBC) test, and a rapid diagnostic test (RDT) had been systematically performed. PCR had been carried out for ambiguous profiles.

RESULTS

Eighty-nine cases recorded from 78 patients were included, 65 of them having recently traveled to French Guyana. Forty-two patients had properly followed chemoprophylaxis. Forty-six cases were primary infections while 43 were relapses. The sensitivity was 91% for the thin blood smear, 96% for the concentration techniques (Giemsa thick blood smear and QBC test), and 76% for the RDT. The combination of the three conventional tools has an imperfect sensitivity, both for the positive diagnosis of malaria (96%) and for the diagnosis of vivax species (80%). In 4% of the cases, the positive diagnosis was established only by the PCR. The species identification was established in 20% by the PCR. The sensibility of thin blood smear and of RDT decreased significantly with full compliance of chemoprophylaxis or primary infection, whereas the decrease of sensibility of concentration techniques was not significant.

CONCLUSIONS

This study illustrates the difficulties encountered in vivax malaria diagnosis, especially in patients who properly followed chemoprophylaxis or with primary infection due to a lower parasitemia. It underlines the lack of sensitivity of RDT for P. vivax and emphasizes the need for systematically combining various diagnosis methods.

摘要

背景

在欧洲诊断的输入性疟疾病例中，间日疟原虫是第二常见的疟原虫种类。本研究旨在描述输入性间日疟原虫感染的寄生虫学检测的敏感性，以及化学预防和发病类型（初次感染或复发）的影响。

方法

回顾性研究纳入了 2001 年至 2013 年期间在法国一家军队医院就诊的输入性间日疟病例。参考诊断方法为聚合酶链反应（PCR）校正的显微镜检查。系统进行了薄血膜和厚血膜检查、定量血涂片（QBC）检测和快速诊断检测（RDT）。对模糊图谱进行了 PCR 检测。

结果

共纳入 78 例患者中的 89 例，其中 65 例患者近期前往法属圭亚那旅行。42 例患者正确遵循了化学预防措施。46 例为初次感染，43 例为复发。薄血涂片的敏感性为 91%，浓缩技术（吉氏厚血涂片和 QBC 检测）的敏感性为 96%，RDT 的敏感性为 76%。三种常规工具的组合对疟疾的阳性诊断（96%）和间日疟原虫的诊断（80%）都有不理想的敏感性。在 4%的病例中，仅通过 PCR 才能确诊。PCR 确定了 20%的物种鉴定。在完全遵循化学预防或初次感染的情况下，薄血涂片和 RDT 的敏感性显著降低，而浓缩技术敏感性的降低则不明显。