汇合血清样本技术筛查云南血吸虫病的初步研究

目的研究汇合血清样本技术用于筛查云南血吸虫感染人群的稀释极限和最适汇合样本数.方法采用随机抽样法,对云南血吸虫病疫区人群抽样采集血样;将所采集的31份阳性血样和24份阴性血样,分别按阳性和阴性样本汇合比为1：1,1：2,1：3,1：4,1：9和1：14随机汇合,共得到汇合样本372份.用IHA检测抗体法,在稀释度分别为1：5,1：10,1：20,1：40四组中共检测1448份汇合血样,与对单份样本检测的效果进行统计分析和比较.结果在稀释度分别为1：5,1：10,1：20,1：40四组中,稀释度为1：5组IHA检测汇合样本的敏感性显著高于其它稀释度的三组,且敏感性随汇合样本数量的增加而降低.在稀释度为1：5组,当汇合样本数小于6时,IHA的敏感性仍高于90%.结论用IHA检测汇合血清样本以筛查血吸虫感染时,汇合样本的稀释限度为1：5,最适汇合血清样本数不大于6,可避免较少地漏检阳性血样.

Study on Pooled Serum Testing for Screening Schistosomiasis Japonica Infection by IHA in Yunnan

Objective To explore the dilution limit and optimum pool size of pooled serum testing（PST） for screening S.japonicum infection in Yunnan.Methods Serum samples of subjects in schistosomiasis japonica epidemic area of Yunnan were collected by random sampling method.31 positive and 24 negative serum samples were randomly mixed by 1：1,1：2,1：3,1：4,1：9 and 1：14,respectively.These mixed sera were then subjected to the IHA test at the dilution titers of 1：5,1：10,1：20 and 1：40.Therefore,the final number of tests for all combinations of pool ratios and dilutions was 372.As each pool had 4 dilution titers,the final number of preparations being tested was 1 448.Results The sensitivity in 1：5 dilution group was significantly higher than that of the other three dilutions（1：10,1：20 and 1：40 dilution group）,and the sensitivity decreased with the increase of the pool size for all dilutions.The sensitivity of IHA was still over 90% in 1：5 dilution group,even when the pool size was less than 6.Conclusion The dilution limit of mixed sera is 1：5 when pooled serum testing（PST） by IHA is used for screening schistosomiasis japonica.It may reduce the missed positive rates by keeping the optimum pool size more than 6.