Department of Intensive Care Medicine, University Medical Centre Hamburg-Eppendorf, 20246, Hamburg, Germany.
BMC Infect Dis. 2013 Jan 30;13:55. doi: 10.1186/1471-2334-13-55.
Acute schistosomiasis constitutes a rare but serious condition in individuals experiencing their first prepatent Schistosoma infection. To circumvent costly and time-consuming diagnostics, an early and rapid diagnosis is required. So far, classic diagnostic tools such as parasite microscopy or serology lack considerable sensitivity at this early stage of Schistosoma infection. To validate the use of a blood based real-time polymerase chain reaction (PCR) test for the detection of Schistosoma DNA in patients with acute schistosomiasis who acquired their infection in various endemic regions we conducted a European-wide prospective study in 11 centres specialized in travel medicine and tropical medicine.
Patients with a history of recent travelling to schistosomiasis endemic regions and freshwater contacts, an episode of fever (body temperature ≥38.5°C) and an absolute or relative eosinophil count of ≥700/μl or 10%, were eligible for participation. PCR testing with DNA extracted from serum was compared with results from serology and microscopy.
Of the 38 patients with acute schistosomiasis included into the study, PCR detected Schistosoma DNA in 35 patients at initial presentation (sensitivity 92%). In contrast, sensitivity of serology (enzyme immunoassay and/or immunofluorescence assay) or parasite microscopy was only 70% and 24%, respectively.
For the early diagnosis of acute schistosomiasis, real-time PCR for the detection of schistosoma DNA in serum is more sensitive than classic diagnostic tools such as serology or microscopy, irrespective of the region of infection. Generalization of the results to all Schistosoma species may be difficult as in the study presented here only eggs of S. mansoni were detected by microscopy. A minimum amount of two millilitre of serum is required for sufficient diagnostic accuracy.
急性血吸虫病是初次感染未成熟血吸虫的个体中一种罕见但严重的病症。为避免昂贵且耗时的诊断，需要进行早期快速诊断。到目前为止，寄生虫显微镜检查或血清学等经典诊断工具在血吸虫感染的早期阶段缺乏相当高的敏感性。为了验证在从各种流行地区获得感染的急性血吸虫病患者中使用基于血液的实时聚合酶链反应（PCR）检测血吸虫 DNA 的有效性，我们在 11 个专门从事旅行医学和热带医学的中心进行了一项全欧前瞻性研究。
有近期前往血吸虫病流行地区和淡水接触史、发热（体温≥38.5°C）以及绝对或相对嗜酸性粒细胞计数≥700/μl 或 10%的患者有资格参与。用从血清中提取的 DNA 进行 PCR 检测，并与血清学和显微镜检查的结果进行比较。
在纳入研究的 38 例急性血吸虫病患者中，PCR 在初次就诊时检测到 35 例患者的血吸虫 DNA（敏感性 92%）。相比之下，血清学（酶免疫测定和/或免疫荧光测定）或寄生虫显微镜检查的敏感性分别为 70%和 24%。
对于急性血吸虫病的早期诊断，实时 PCR 检测血清中的血吸虫 DNA 比经典诊断工具（如血清学或显微镜检查）更敏感，而与感染区域无关。由于在本研究中仅通过显微镜检测到 S. mansoni 的卵，因此将结果推广到所有血吸虫种可能存在困难。需要至少两毫升血清才能获得足够的诊断准确性。
