Fei Hu, Zhao-Jun Li, Yi-Feng Li, Min Yuan, Shu-Ying Xie, Yue-Min Liu, Jian-Ying Li, Zu-Lu Gao, Yong Pu, Jin-Ming Wang, Dan-Dan Lin
Jiangxi Provincial Institute of Parasitic Diseases, Nanchang 330046, China.
Xingzi Anti-schistosomiasis Station, Jiangxi Province, China.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2016 Nov 24;28(6):644-647. doi: 10.16250/j.32.1374.2016181.
To explore the cut-off value of the indirect haemagglutination test (IHA) method for schistosomiasis japonica diagnosis in different endemic areas.
Totally 55 nature villages of the lake-type endemic counties, Yugan and Xinzi, in Poyang Lake Region of Jiangxi Province were chosen as the study fields, and all the villagers over 5 years old were parallelly examined by Kato-Katz method + miracidial hatching test and IHA method. The detection data were analyzed by the correlation analysis, and the threshold values of the IHA method in different endemic areas were decided by the receiver operating characteristic (ROC) curve.
The positive rate of stool examinations of the villagers was correlated with the distribution trend of the antibody level of whole population ( = 0.588, ＜ 0.05), but no correlation with the antibody level of the positive population ( = 0.221, ＞ 0.05). The antibody level of stool-negative population during the period of 2008 to 2011 detected by IHA method dropped year by year, and the annual difference was statistically significant ( = 3.650, ＜ 0.05). While the antibody level of stool-positive population found during the period of 2008 to 2011 maintained a certain high level in the 4 years, and there was no statistically significant difference among them ( = 2.461, ＞ 0.05). When the positive rates were <1%, 1%-5% or >5%, the specificity of diagnosis could be improved when 1∶80, 1∶20 and 1∶10 were used as the cut-off values of IHA correspondingly.
The different threshold values for diagnosis of schistosomiasis japonica should be considered while using IHA method to screen out patients in different endemic areas.
探讨间接血凝试验（IHA）法诊断不同流行区日本血吸虫病的截断值。
选取江西省鄱阳湖地区湖沼型流行县余干县和新建县的55个自然村作为研究现场，对所有5岁以上村民同时采用加藤-卡氏法+毛蚴孵化法和IHA法进行检查。采用相关性分析对检测数据进行分析，通过绘制受试者工作特征（ROC）曲线确定不同流行区IHA法的阈值。
村民粪便检查阳性率与人群抗体水平分布趋势呈正相关（r = 0.588，P ＜ 0.05），但与阳性人群抗体水平无相关性（r = 0.221，P ＞ 0.05）。IHA法检测2008 - 2011年期间粪便阴性人群抗体水平逐年下降，年度差异有统计学意义（F = 3.650，P ＜ 0.05）。而2008 - 2011年期间粪便阳性人群抗体水平4年维持在一定高水平，差异无统计学意义（F = 2.461，P ＞ 0.05）。当阳性率＜1%、1% - 5%或＞5%时，分别以1∶80、1∶20和1∶10作为IHA法的截断值可提高诊断特异性。
应用IHA法在不同流行区筛查日本血吸虫病患者时，应考虑采用不同的诊断阈值。
