Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, USA.
PLoS Negl Trop Dis. 2013 Jul 4;7(7):e2265. doi: 10.1371/journal.pntd.0002265. Print 2013.
To determine the sensitivity, specificity, and field utility of the Cepheid GeneXpert Chlamydia trachomatis (CT) Assay (GeneXpert) for ocular chlamydia infection compared to Roche Amplicor CT assay (Amplicor).
In a trachoma-endemic community in Kongwa Tanzania, 144 children ages 0 to 9 were surveyed to assess clinical trachoma and had two ocular swabs taken. One swab was processed at Johns Hopkins University, Baltimore MD, using Amplicor, (Roche Molecular Diagnostics) and the other swab was processed at a field station in Kongwa using the GeneXpert Chlamydia trachomatis/Neisseria gonorrhoeae assay (Cepheid). The sensitivity and specificity of GeneXpert was compared to the Amplicor assay.
Of the 144 swabs taken the prevalence of follicular trachoma by clinical exam was 43.7%, and by evidence of infection according to Amplicor was 28.5%. A total of 17 specimens (11.8%) could not be processed by GeneXpert in the field due to lack of sample volume, other specimen issues or electricity failure. The sensitivity of GeneXpert when compared to Amplicor was 100% and the specificity was 95%. The GeneXpert test identified more positives in individuals with clinical trachoma than Amplicor, 55% versus 52%.
The GeneXpert test for C. trachomatis performed with high sensitivity and specificity and demonstrated excellent promise as a field test for trachoma control.
比较罗氏 Amplicor CT 检测法（Amplicor）与 Cepheid GeneXpert 沙眼衣原体（CT）检测法（GeneXpert）检测眼部 CT 感染的灵敏度、特异性和现场实用性。
在坦桑尼亚 Kongwa 的一个沙眼流行社区，对 144 名 0 至 9 岁的儿童进行了调查，以评估临床沙眼并采集了两份眼部拭子。一份拭子在马里兰州巴尔的摩的约翰霍普金斯大学使用 Amplicor（罗氏分子诊断）进行处理，另一份在 Kongwa 的现场站使用 GeneXpert 沙眼衣原体/淋病奈瑟菌检测法（Cepheid）进行处理。比较了 GeneXpert 与 Amplicor 检测法的灵敏度和特异性。
在采集的 144 份拭子中，临床检查滤泡性沙眼的患病率为 43.7%，根据 Amplicor 的感染证据患病率为 28.5%。由于样本量不足、其他样本问题或停电，共有 17 份标本（11.8%）无法在现场用 GeneXpert 进行处理。与 Amplicor 相比，GeneXpert 的灵敏度为 100%，特异性为 95%。GeneXpert 检测法在有临床沙眼的个体中比 Amplicor 检测法检测到更多的阳性结果，分别为 55%和 52%。
GeneXpert 检测 CT 的灵敏度和特异性均较高，在沙眼控制的现场检测中具有良好的应用前景。
