Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
PLoS Negl Trop Dis. 2013 Aug 29;7(8):e2413. doi: 10.1371/journal.pntd.0002413. eCollection 2013.
Diagnosis of urogenital schistosomiasis by microscopy and serological tests may be elusive in travelers due to low egg load and the absence of seroconversion upon arrival. There is need for a more sensitive diagnostic test. Therefore, we developed a real-time PCR targeting the Schistosoma haematobium-specific Dra1 sequence.
METHODOLOGY/PRINCIPAL FINDINGS: The PCR was evaluated on urine (n = 111), stool (n = 84) and serum samples (n = 135), and one biopsy from travelers and migrants with confirmed or suspected schistosomiasis. PCR revealed a positive result in 7/7 urine samples, 11/11 stool samples and 1/1 biopsy containing S. haematobium eggs as demonstrated by microscopy and in 22/23 serum samples from patients with a parasitological confirmed S. haematobium infection. S. haematobium DNA was additionally detected by PCR in 7 urine, 3 stool and 5 serum samples of patients suspected of having schistosomiasis without egg excretion in urine and feces. None of these suspected patients demonstrated other parasitic infections except one with Blastocystis hominis and Entamoeba cyst in a fecal sample. The PCR was negative in all stool samples containing S. mansoni eggs (n = 21) and in all serum samples of patients with a microscopically confirmed S. mansoni (n = 22), Ascaris lumbricoides (n = 1), Ancylostomidae (n = 1), Strongyloides stercoralis (n = 1) or Trichuris trichuria infection (n = 1). The PCR demonstrated a high specificity, reproducibility and analytical sensitivity (0.5 eggs per gram of feces).
CONCLUSION/SIGNIFICANCE: The real-time PCR targeting the Dra1 sequence for S. haematobium-specific detection in urine, feces, and particularly serum, is a promising tool to confirm the diagnosis, also during the acute phase of urogenital schistosomiasis.
由于卵负荷低且到达时未发生血清转化，镜检和血清学检测可能难以诊断泌尿生殖系统血吸虫病。因此，我们需要一种更敏感的诊断检测方法。为此，我们开发了一种针对埃及血吸虫特异性 Dra1 序列的实时 PCR。
方法/主要发现：该 PCR 对旅行者的尿液（n=111）、粪便（n=84）和血清样本（n=135）以及 1 份活检样本进行了评估，这些样本来自确诊或疑似患有血吸虫病的旅行者和移民。PCR 在 7/7 份含有埃及血吸虫卵的尿液样本、11/11 份粪便样本和 1/1 份活检样本中显示阳性结果，这些样本通过显微镜检查证实，在 23 份血清样本中，22 份来自寄生虫学证实的埃及血吸虫感染患者。PCR 还在 7 份尿液、3 份粪便和 5 份疑似无尿和粪便中排出埃及血吸虫卵的患者的血清样本中检测到埃及血吸虫 DNA。除了一份粪便样本中存在溶组织内阿米巴和蓝氏贾第鞭毛虫外，这些疑似患者的所有其他寄生虫感染均为阴性。PCR 在所有含有曼氏血吸虫卵的粪便样本（n=21）和所有显微镜证实的曼氏血吸虫（n=22）、蛔虫（n=1）、钩虫（n=1）、粪类圆线虫（n=1）或毛首鞭形线虫感染（n=1）患者的血清样本中均为阴性。该 PCR 显示出高特异性、重现性和分析灵敏度（粪便中每克 0.5 个卵）。
结论/意义：针对埃及血吸虫特异性 Dra1 序列的实时 PCR 可用于检测尿液、粪便，特别是血清，是一种有前途的工具，可用于确认诊断，特别是在泌尿生殖系统血吸虫病的急性阶段。
