Nokes D J, Nigatu W, Abebe A, Messele T, Dejene A, Enquselassie F, Vyse A, Brown D, Cutts F T
Department of Biological Sciences, University of Warwick, Coventry, UK.
Trop Med Int Health. 1998 Apr;3(4):258-67. doi: 10.1046/j.1365-3156.1998.00227.x.
To assess the utility of oral fluid compared with serum for the determination of age-prevalence of rubella-specific antibodies in an urban African community setting.
Paired serum and oral fluid samples were collected from 439 individuals aged 0-49 years in Addis Ababa, Ethiopia, as part of a larger seroepidemiological survey in 1994. Oral fluid was sampled using a simple sponge device that was well accepted by subjects of all ages; venous blood was collected by Vacutainer system. We measured rubella-specific antibodies in serum by the Radial Haemolysis (RH) test, supported by two confirmatory assays, and in oral fluid by IgG antibody-capture radioimmunoassay (GACRIA).
Sensitivity and specificity of oral fluid results compared to serum were 89% and 76%, respectively. Sensitivity declined from 96% in age group 0-19 years to 90% in age group 20-29 and 78% in age group 30-49. Specificity was 86% in 0-9 year olds contrasting with 61% in older groups (10-49 years). The positive predictive value of an oral fluid sample was high in all age groups (range 92-100%), while the negative predictive value declined from > or =80% in those aged <10 years to <10% in those aged > or =30 years. Serum confirmatory tests suggested a proportion of false serum RH negatives, increasing with age, indicating a need to standardize serum as well as oral fluid tests.
In the community setting of a developing country, oral fluid surveys could be useful to estimate age-prevalence of rubella immunity and identify rubella-susceptible children for follow-up. Further work is required to simplify assays and sample processing, improve assay sensitivity and estimate assay specificity more precisely, and compare and standardise collection methods suitable for surveillance of a variety of childhood viral infections.
在非洲城市社区环境中，评估与血清相比，口腔液用于测定风疹特异性抗体年龄患病率的效用。
作为1994年一项更大规模血清流行病学调查的一部分，从埃塞俄比亚亚的斯亚贝巴439名0至49岁的个体中采集了配对的血清和口腔液样本。使用一种简单的海绵装置采集口腔液，该装置受到所有年龄段受试者的广泛接受；通过真空采血管系统采集静脉血。我们通过放射溶血（RH）试验并辅以两种确证试验来测定血清中的风疹特异性抗体，通过IgG抗体捕获放射免疫测定法（GACRIA）来测定口腔液中的风疹特异性抗体。
与血清相比，口腔液检测结果的敏感性和特异性分别为89%和76%。敏感性从0至19岁年龄组的96%下降到20至29岁年龄组的90%以及30至49岁年龄组的78%。0至9岁儿童的特异性为86%，而年龄较大组（10至49岁）为61%。口腔液样本的阳性预测值在所有年龄组中都很高（范围为92%至100%），而阴性预测值从10岁以下人群的≥80%下降到30岁及以上人群的<10%。血清确证试验表明，血清RH假阴性比例随年龄增加，这表明需要对血清以及口腔液检测进行标准化。
在发展中国家的社区环境中，口腔液调查可能有助于估计风疹免疫力的年龄患病率，并识别风疹易感儿童以便进行随访。需要进一步开展工作来简化检测方法和样本处理，提高检测敏感性并更精确地估计检测特异性，以及比较和标准化适用于多种儿童期病毒感染监测的采集方法。
