Knox Janet, Tabrizi Sepehr N, Miller Penny, Petoumenos Kathy, Law Mathew, Chen Shujun, Garland Suzanne M
Sexual Health Unit of Territory Health Services, Alice Springs, Northern Territory, Australia.
Sex Transm Dis. 2002 Nov;29(11):647-54. doi: 10.1097/00007435-200211000-00006.
Self-collected samples have been shown to be an acceptable and sensitive method for the detection by polymerase chain reaction (PCR) of sexually transmitted infections (STIs) among women. GOAL The goal of the study was to compare self-collected sampling methods to conventional practitioner endocervical sampling for the PCR detection of Chlamydia trachomatis and Neisseria gonorrhoeae to compare two self-collected sampling methods for the detection of T vaginalis by PCR.
Women (n = 318) from urban and remote areas of central Australia participated in the study when attending their health clinic for a check-up. They each provided a FVU sample, self-collected vaginal swab specimen, and tampon specimen. This was followed by a clinical examination by a practitioner, with collection of endocervical and high vaginal swabs for testing by conventional microscopy and culture for N gonorrhoeae and T vaginalis, respectively. The FVU, self-collected vaginal swab, tampon, and endocervical swab specimens were tested by Roche Cobas Amplicor for C trachomatis and N gonorrhoeae. The self-collected vaginal swab and tampon specimens were also tested by an in-house PCR method for the detection of T vaginalis.
In toto, C trachomatis was detected by PCR in 11.5%, N gonorrhoeae in 11.8%, and T vaginalis in 24.6%. Molecular diagnostics for N gonorrhoeae and T vaginalis were significantly more sensitive than traditional assays with microscopy and culture. For the detection of C trachomatis by PCR, tampons were the most sensitive (100.0%) and urine the least sensitive (72.7%) specimens ( = 0.01). For the detection of by PCR, the self-collected tampon was the most sensitive specimen, followed by the endocervical swab, self-collected swab, and urine specimen, with sensitivities of 97.2%, 92.6%, 71.9%, and 31.2%, respectively. For detection of N gonorrhoeae, statistically significant differences were detected for urine versus tampon ( < 0.0001), endocervical swab ( < 0.001), and self-collected swab ( = 0.01) and for self-collected swab versus tampon ( = 0.01). Subsequent data collection showed that sensitivity of urine PCR for detection of N gonorrhoeae improved with freezing of urine specimens and shorter transport time. Tampons were also more sensitive than self-collected swabs for detection of T vaginalis (sensitivity of 100% versus 87.7%).
Self-collected specimens offer women in remote communities an acceptable and sensitive alternative method of testing for STIs. The low sensitivity of N gonorrhoeae PCR of urine specimens may reflect poor transport and storage conditions, which we have shown can be improved by freezing urine specimens and reducing transport delays.
自我采集样本已被证明是一种可接受且敏感的方法，用于通过聚合酶链反应（PCR）检测女性性传播感染（STIs）。目的：本研究的目的是比较自我采集采样方法与传统医生宫颈采样方法，以通过PCR检测沙眼衣原体和淋病奈瑟菌，并比较两种自我采集采样方法通过PCR检测阴道毛滴虫的情况。
来自澳大利亚中部城市和偏远地区的318名女性在前往健康诊所进行检查时参与了本研究。她们每人提供了一份首次排尿尿液（FVU）样本、自我采集的阴道拭子标本和棉塞标本。随后由医生进行临床检查，采集宫颈管和阴道上段拭子，分别通过传统显微镜检查和培养检测淋病奈瑟菌和阴道毛滴虫。FVU、自我采集的阴道拭子、棉塞和宫颈管拭子标本通过罗氏Cobas Amplicor检测沙眼衣原体和淋病奈瑟菌。自我采集的阴道拭子和棉塞标本也通过一种内部PCR方法检测阴道毛滴虫。
总体而言，通过PCR检测出沙眼衣原体的比例为11.5%，淋病奈瑟菌为11.8%，阴道毛滴虫为24.6%。淋病奈瑟菌和阴道毛滴虫的分子诊断方法比传统的显微镜检查和培养检测方法明显更敏感。对于通过PCR检测沙眼衣原体，棉塞是最敏感的标本（100.0%），尿液是最不敏感的标本（72.7%）（P = 0.01）。对于通过PCR检测阴道毛滴虫，自我采集的棉塞是最敏感的标本，其次是宫颈管拭子、自我采集的拭子和尿液标本，敏感性分别为97.2%、92.6%、71.9%和31.2%。对于检测淋病奈瑟菌，尿液与棉塞（P < 0.0001）、宫颈管拭子（P < 0.001）和自我采集的拭子（P = 0.01）之间以及自我采集的拭子与棉塞之间（P = 0.01）检测到有统计学显著差异。后续数据收集表明，尿液标本冷冻和运输时间缩短后，尿液PCR检测淋病奈瑟菌的敏感性有所提高。棉塞在检测阴道毛滴虫方面也比自我采集的拭子更敏感（敏感性分别为100%和87.7%）。
自我采集标本为偏远社区的女性提供了一种可接受且敏感的性传播感染检测替代方法。尿液标本淋病奈瑟菌PCR检测敏感性低可能反映了运输和储存条件差，我们已表明通过冷冻尿液标本和减少运输延迟可以改善这种情况。
