Eisenberg J N, Priest J W, Lammie P J, Colford J M
School of Public Health, University of California, Berkeley, 94720-7360, USA.
Emerg Infect Dis. 2001 Nov-Dec;7(6):1004-9. doi: 10.3201/eid0706.010614.
Advances in serologic assays for Cryptosporidium parvum have made serology an attractive surveillance tool. The sensitivity, specificity, and predictive value of these new assays for surveillance of immunocompromised populations, however, have not been reported. Using stored serum specimens collected for the San Francisco Men's Health Study, we conducted a case-control study with 11 clinically confirmed cases of cryptosporidiosis. Based on assays using a 27-kDa antigen (CP23), the serum specimens from cases had a median response immunoglobulin (Ig) G level following clinical diagnosis (1,334) and a net response (433, change in IgG level from baseline) that were significantly higher than their respective control values (329 and -32, Wilcoxon p value = 0.01). Receiver operator curves estimated a cutoff of 625 U as the optimal sensitivity (0.86 [0.37, 1.0]) and specificity (0.86 [0.37, 1.0]) for predicting Cryptosporidium infection. These data suggest that the enzyme-linked immunosorbent assay technique can be an effective epidemiologic tool to monitor Cryptosporidium infection in immunocompromised populations.
用于检测微小隐孢子虫的血清学检测方法的进展使血清学成为一种有吸引力的监测工具。然而，这些新检测方法在免疫功能低下人群监测中的敏感性、特异性和预测价值尚未见报道。我们利用为旧金山男性健康研究收集的储存血清标本，对11例临床确诊的隐孢子虫病病例进行了病例对照研究。基于使用27-kDa抗原（CP23）的检测，病例组血清标本在临床诊断后的中位反应免疫球蛋白（Ig）G水平（1334）和净反应（433，IgG水平相对于基线的变化）显著高于各自的对照值（329和-32，Wilcoxon p值=0.01）。受试者工作特征曲线估计，以625 U为临界值时，预测隐孢子虫感染的敏感性（0.86 [0.37, 1.0]）和特异性（0.86 [0.37, 1.0]）最佳。这些数据表明，酶联免疫吸附测定技术可成为监测免疫功能低下人群隐孢子虫感染的有效流行病学工具。
