Fang Junyong, Husman Constance, DeSilva Lalitha, Chang Ruzhang, Peralta Ligia
Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
J Pediatr Adolesc Gynecol. 2008 Dec;21(6):355-60. doi: 10.1016/j.jpag.2008.03.010.
To assess the concordance of self-obtained vaginal swabs (SVS), first void urine samples (FVU) and provider-collected endocervical swabs (PES) for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhea (NG) in adolescents.
A total of 342 adolescent women and 1080 baseline and semi-annual visits were analyzed. FVU, SVS and PES were collected at each biannual visit. All specimens were tested by BDProbeTec ET(trade mark) Amplified DNA Assay. Sensitivity, specificity, positive predictive value (PPV) negative predictive value (NPV) and kappa coefficient were calculated to evaluate the ability to identify possible infected cases using samples from three anatomic sites and the test agreement between any two of these three specimen types. Positive results from at least two of the three specimens collected from same subject at the same study visit was considered true positive.
The positivity rates for CT and NG were 26.6 and 11.7 per 100 women respectively. The sensitivities of SVS, FVU and PES for detecting CT were 97.3%, 89.2% and 90.1% respectively. For the detection of NG, the sensitivities of the three sampling methods were 100%, 88.6% and 95.5% respectively. The specificities were between 94.7% and 99.7% for both CT and NG. Kappa coefficients of CT test results were 0.89, 0.88 and 0.83 for specimen pairs SVSvsPES, SVSvsFVU and PESvsFVU respectively. For the detection of NG, kappa coefficients were 0.91, 0.87 and 0.91 for these three pairs (all P<0.0001). Kappa>0.75 is considered excellent agreement between specimens.
There were strong agreements among SVS, PES and FVU specimens on the detection of CT and NG infections in adolescent females using nucleic acid amplification test. SVS represented as high as or more sensitive an approach for detecting both CT and NG compared to PES. Although FVU was the least sensitive sampling method, it is also the least invasive method. Thus SVS and FVU may provide a reliable alternative to endocervical specimens for CT and NG screening.
评估自行采集的阴道拭子（SVS）、首次晨尿样本（FVU）和医护人员采集的宫颈拭子（PES）在检测青少年沙眼衣原体（CT）和淋病奈瑟菌（NG）方面的一致性。
对342名青春期女性进行了分析，共进行了1080次基线和半年期随访。每次半年期随访时采集FVU、SVS和PES。所有标本均采用BDProbeTec ET（商标）DNA扩增检测法进行检测。计算敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）和kappa系数，以评估使用来自三个解剖部位的样本识别可能感染病例的能力以及这三种标本类型中任意两种之间的检测一致性。在同一研究访视时从同一受试者采集的三个标本中至少有两个呈阳性结果被视为真阳性。
CT和NG的阳性率分别为每100名女性26.6例和11.7例。SVS、FVU和PES检测CT的敏感性分别为97.3%、89.2%和90.1%。对于NG的检测，三种采样方法的敏感性分别为100%、88.6%和95.5%。CT和NG的特异性均在94.7%至99.7%之间。CT检测结果中，SVS与PES、SVS与FVU、PES与FVU标本对的kappa系数分别为0.89、0.88和0.83。对于NG的检测，这三对标本的kappa系数分别为0.91、0.87和0.91（所有P<0.0001）。Kappa>0.75被认为标本之间一致性良好。
在使用核酸扩增检测法检测青春期女性CT和NG感染方面，SVS、PES和FVU标本之间具有高度一致性。与PES相比，SVS在检测CT和NG方面具有同样高或更高的敏感性。虽然FVU是最不敏感的采样方法，但也是侵入性最小的方法。因此，SVS和FVU可能为CT和NG筛查提供一种可靠的替代宫颈标本的方法。
