在疟原虫、间日疟原虫和诺氏疟原虫流行的地区，显微镜检查对疟原虫种的区分存在局限性。
Limitations of microscopy to differentiate Plasmodium species in a region co-endemic for Plasmodium falciparum, Plasmodium vivax and Plasmodium knowlesi.
机构信息
Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia.
出版信息
Malar J. 2013 Jan 8;12:8. doi: 10.1186/1475-2875-12-8.
BACKGROUND
In areas co-endemic for multiple Plasmodium species, correct diagnosis is crucial for appropriate treatment and surveillance. Species misidentification by microscopy has been reported in areas co-endemic for vivax and falciparum malaria, and may be more frequent in regions where Plasmodium knowlesi also commonly occurs.
METHODS
This prospective study in Sabah, Malaysia, evaluated the accuracy of routine district and referral hospital-based microscopy, and microscopy performed by an experienced research microscopist, for the diagnosis of PCR-confirmed Plasmodium falciparum, P. knowlesi, and Plasmodium vivax malaria.
RESULTS
A total of 304 patients with PCR-confirmed Plasmodium infection were enrolled, including 130 with P. knowlesi, 122 with P. falciparum, 43 with P. vivax, one with Plasmodium malariae and eight with mixed species infections. Among patients with P. knowlesi mono-infection, routine and cross-check microscopy both identified 94 (72%) patients as "P. malariae/P. knowlesi"; 17 (13%) and 28 (22%) respectively were identified as P. falciparum, and 13 (10%) and two (1.5%) as P. vivax. Among patients with PCR-confirmed P. falciparum, routine and cross-check microscopy identified 110/122 (90%) and 112/118 (95%) patients respectively as P. falciparum, and 8/122 (6.6%) and 5/118 (4.2%) as "P. malariae/P. knowlesi". Among those with P. vivax, 23/43 (53%) and 34/40 (85%) were correctly diagnosed by routine and cross-check microscopy respectively, while 13/43 (30%) and 3/40 (7.5%) patients were diagnosed as "P. malariae/P. knowlesi". Four of 13 patients with PCR-confirmed P. vivax and misdiagnosed by routine microscopy as "P. malariae/P. knowlesi" were subsequently re-admitted with P. vivax malaria.
CONCLUSIONS
Microscopy does not reliably distinguish between P. falciparum, P. vivax and P. knowlesi in a region where all three species frequently occur. Misdiagnosis of P. knowlesi as both P. vivax and P. falciparum, and vice versa, is common, potentially leading to inappropriate treatment, including chloroquine therapy for P. falciparum and a lack of anti-relapse therapy for P. vivax. The limitations of microscopy in P. knowlesi-endemic areas supports the use of unified blood-stage treatment strategies for all Plasmodium species, the development of accurate rapid diagnostic tests suitable for all species, and the use of PCR-confirmation for accurate surveillance.
背景
在多种疟原虫流行地区，正确诊断对于适当的治疗和监测至关重要。在间日疟和恶性疟流行地区已经报道了显微镜检查的物种错误鉴定，在基孔肯雅热也常见的地区，这种错误可能更为频繁。
方法
本研究在马来西亚沙巴进行，评估了地区和转诊医院基于显微镜的常规检测，以及经验丰富的研究显微镜检查人员进行的检测，用于诊断经 PCR 确认的恶性疟原虫、间日疟原虫和卵形疟原虫疟原虫。
结果
共纳入 304 例经 PCR 确认的疟原虫感染患者，包括 130 例基孔肯雅热疟原虫感染、122 例恶性疟原虫感染、43 例间日疟原虫感染、1 例卵形疟原虫感染和 8 例混合感染。在基孔肯雅热疟原虫单感染患者中，常规和交叉检查显微镜均将 94 例（72%）患者识别为“疟原虫/基孔肯雅热疟原虫”；分别有 17 例（13%）和 28 例（22%）被识别为恶性疟原虫，13 例（10%）和 2 例（1.5%）为间日疟原虫。在经 PCR 确认的恶性疟原虫感染患者中，常规和交叉检查显微镜分别将 110/122（90%）和 112/118（95%）例患者识别为恶性疟原虫，将 8/122（6.6%）和 5/118（4.2%）识别为“疟原虫/基孔肯雅热疟原虫”。在间日疟原虫感染患者中，常规和交叉检查显微镜分别正确诊断了 23/43（53%）和 34/40（85%）例，而分别有 13/43（30%）和 3/40（7.5%）例被诊断为“疟原虫/基孔肯雅热疟原虫”。4 例经 PCR 确认的间日疟原虫感染且常规显微镜检查误诊为“疟原虫/基孔肯雅热疟原虫”的患者随后因间日疟原虫感染再次入院。
结论
在三种疟原虫均流行的地区，显微镜检查不能可靠地区分恶性疟原虫、间日疟原虫和基孔肯雅热疟原虫。基孔肯雅热疟原虫被误诊为间日疟原虫和恶性疟原虫，反之亦然，这很常见，可能导致治疗不当，包括对恶性疟原虫使用氯喹治疗和间日疟原虫缺乏抗复发治疗。在基孔肯雅热疟原虫流行地区显微镜检查的局限性支持对所有疟原虫采用统一的血期治疗策略、开发适合所有物种的准确快速诊断测试以及使用 PCR 进行准确监测。
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