Erdoğan Emrah, Yürük Merve, Sivcan Eda, Karaca Serkan, Yıldız Orhan, Şahin İzzet
Erciyes University Faculty of Medicine, Department of Medical Parasitology, Kayseri, Turkey.
Erciyes University Faculty of Medicine, Department of Infectious Diseases and Clinical Microbiology, Kayseri, Turkey.
Mikrobiyol Bul. 2019 Jan;53(1):106-113. doi: 10.5578/mb.67713.
Malaria caused by Plasmodium species continues to affect the half of the world population. According to the World Health Organization 2017 data, 445.000 cases of malaria and 219 million cases of new clinical malaria cases were reported during the year. African continent is the geographical region where the disease is most frequent. In recent years there has been an increase in the number of imported cases after travels to this continent. In this case report, relaps caused by Plasmodium ovale in a male Republic of Turkey citizen patient who has travelled to Uganda only and no other place a year and half ago was presented. Thin blood smear was prepared from the peripheral blood of the patient who admitted to our hospital with complaints of fever and chills. The smear was stained with Giemsa and examined with a x100 objective microscope and trophozoites belonging to Plasmodium genus were detected. Considering the size and locality of the trophozoites in the erythrocytes, it is thought that the parasite may be Plasmodium vivax. Nested PCR method was used for the species identification. Nested PCR studies were performed using Plasmodium genus and specific primers for P.vivax, Plasmodium falciparum, P.ovale and Plasmodium malariae. Nested PCR products were run on gel and P.ovale was visualized in 787 bp region. P.vivax, P.malariae, P.falciparum, P.ovale and Plasmodium knowlesi species specific primers and probe-based quantitative real-time PCR (qRt-PCR) study revealed that the patient was infected with P.ovale. The patient had no history of chronic illness but had a history of recovered malaria 7-8 years ago. The patient did not have any complaints other than these complaints. CMV IgM and IgG and Brucella aglutinisation tests were negative. It is clear that relapse cases can also be seen when P.ovale species are in hypnozoite stage in the liver. Although there are 18 reported cases of relapse in the last century, these phenomena do not provide sufficient evidence for the theory of relapse. A true relapse is thought to be mild symptoms and even subclinical disease. It is also known that it is difficult to distinguish a true recurrence in cases of relapses that can occur after a long time from primer infection. The best way to overcome this difficulty is to assume being in a malaria endemic area or not between primary infection and recurrence. We think that the applications that are carried out together with the microscope and molecular studies, especially in cases where there is relapses in which low parasitemia or travel story are insufficient, are extremely important both in terms of diagnosis and accurate identification of species and in the selection of treatment.
疟原虫引起的疟疾继续影响着世界上一半的人口。根据世界卫生组织2017年的数据，当年报告了44.5万例疟疾病例和2.19亿例新的临床疟疾病例。非洲大陆是该疾病最常见的地理区域。近年来，前往该大陆旅行后输入性病例的数量有所增加。在本病例报告中，介绍了一名仅在一年半前前往乌干达且无其他旅行史的土耳其共和国男性公民患者，由卵形疟原虫引起的复发情况。对因发热和寒战症状入院的患者外周血制备了薄血涂片。涂片用吉姆萨染色，并用100倍物镜显微镜检查，检测到属于疟原虫属的滋养体。考虑到红细胞内滋养体的大小和位置，认为该寄生虫可能是间日疟原虫。采用巢式PCR方法进行物种鉴定。使用疟原虫属以及间日疟原虫、恶性疟原虫、卵形疟原虫和三日疟原虫的特异性引物进行巢式PCR研究。巢式PCR产物在凝胶上电泳，在787bp区域可见卵形疟原虫。间日疟原虫、三日疟原虫、恶性疟原虫、卵形疟原虫和诺氏疟原虫物种特异性引物及基于探针的定量实时PCR（qRt-PCR）研究表明该患者感染了卵形疟原虫。该患者无慢性疾病史，但7-8年前有疟疾康复史。除上述症状外，患者无其他不适。巨细胞病毒IgM和IgG以及布鲁氏菌凝集试验均为阴性。很明显，当卵形疟原虫物种在肝脏处于休眠子阶段时也会出现复发病例。尽管在上个世纪报告了18例复发病例，但这些现象并未为复发理论提供充分证据。真正的复发被认为是症状轻微甚至是亚临床疾病。还已知在初次感染后很长时间可能发生的复发病例中，很难区分真正的复发。克服这一困难的最佳方法是判断在初次感染和复发之间是否处于疟疾流行地区。我们认为，特别是在低疟原虫血症或旅行史不足以诊断复发的情况下，与显微镜检查和分子研究一起进行的检测，对于诊断、准确鉴定物种以及选择治疗方法都极为重要。
