Van Lieshout L, Panday U G, De Jonge N, Krijger F W, Oostburg B F, Polderman A M, Deelder A M
Laboratory of Parasitology, University of Leiden, Netherlands.
Acta Trop. 1995 Mar;59(1):19-29. doi: 10.1016/0001-706x(94)00084-e.
We evaluated the applicability of circulating antigen detection in serum and urine for the diagnosis of Schistosoma infections in a low endemic area. In total 389 individuals from Saramacca (Surinam) participated in the survey. Stool samples were examined using the Kato method, while circulating anodic antigen (CAA) and circulating cathodic antigen (CCA) were determined by highly specific monoclonal antibody-based ELISA's. Also schistosome specific IgM antibodies were measured by the indirect immunofluorescence assay, but the diagnostic performance of this test was found to be poor in this population. S. mansoni eggs were found in 29% of the examined cases, while CAA and CCA could be demonstrated in 23% and 17% of the serum samples and in 3% and 28% of the urine samples, respectively. Forty three percent of the study population was positive in at least one of these diagnostic assays, indicating that each individual test misses a substantial part of the subjects with an active infection. In most positive cases, intensities of infection were very low. As 204 individuals participated in all screening assays, diagnostic performance of each test was evaluated in this sub-population. The highest sensitivities were achieved with the urine-CCA assay and the parasitological examination, detecting 59 and 58 out of the 107 cases with an active infection, respectively. The serum-CAA assay detected 47 positive cases. Our results demonstrate that determination of circulating antigens, especially CCA in urine and CAA in serum, provides information additional to the parasitological examination, for the assessment of prevalence and intensity of Schistosoma infection in low endemic areas.
我们评估了血清和尿液中循环抗原检测在低流行地区诊断血吸虫感染的适用性。共有来自苏里南萨拉马卡的389人参与了这项调查。粪便样本采用加藤法进行检查，而循环阳极抗原（CAA）和循环阴极抗原（CCA）则通过基于高特异性单克隆抗体的酶联免疫吸附测定法进行测定。同时，通过间接免疫荧光测定法检测血吸虫特异性IgM抗体，但发现该检测方法在该人群中的诊断性能较差。在29%的受检病例中发现了曼氏血吸虫卵，而血清样本中分别有23%和17%可检测到CAA和CCA，尿液样本中分别有3%和28%可检测到CAA和CCA。43%的研究人群至少在其中一项诊断检测中呈阳性，这表明每项单独检测都遗漏了相当一部分活动性感染的受试者。在大多数阳性病例中，感染强度非常低。由于204人参与了所有筛查检测，因此在该亚人群中评估了每项检测的诊断性能。尿液-CCA检测和寄生虫学检查的灵敏度最高，在107例活动性感染病例中分别检测到59例和58例。血清-CAA检测发现了47例阳性病例。我们的结果表明，循环抗原的测定，尤其是尿液中的CCA和血清中的CAA，为评估低流行地区血吸虫感染的流行率和感染强度提供了寄生虫学检查之外的额外信息。
