Hatori Toru, Nakamura Tamiko, Tsukui Satoshi
Maebashi municipal public health center.
Nihon Koshu Eisei Zasshi. 2013;60(11):691-6.
Serum levels of antibody against Chlamydia trachomatis are used routinely to diagnose chlamydial infection among patients undergoing counseling and testing for sexually transmitted disease at public health centers in Japan, whereas tests for pathogen detection are conducted at most clinics. The objective of the present study was to evaluate the usefulness of a test for detecting C. trachomatis and to compare it with that of screening for serum chlamydia antibodies at a public health center.
Serum chlamydia antibody titers were estimated using an ELISA, while C. trachomatis was detected in the urine using the nucleic acid amplification assay that included strand displacement amplification (SDA). We compared the results of 120 patients (64 men and 56 women), because the sensitivity of the method using urine samples from women has been reported to be as high as that using cervical samples. The serum antibody test results were considered to be positive when either one or both of the IgA and IgG antibodies were positive.
The overall prevalence of positive results for the antibody test was 24.2% (14.1% for men and 35.7% for women), and that for the SDA method was 7.5% (3.1% for men and 12.5% for women). The concordance rate of the 2 tests was 81.7%, with a kappa statistic of 0.35 (95% CI, 0.10-0.59). Of the 9 subjects who were positive for C. trachomatis using the SDA assay, 1 had serum chlamydia IgA antibodies, 6 had IgG antibodies, 1 had both the antibodies, and 1 had no antibodies. On the other hand, of the 111 subjects who were negative for C. trachomatis, only 8 had chlamydia IgA antibodies, 5 had IgG antibodies, and 8 had both the antibodies. These results indicated there was no association between serum IgA antibodies and the presence of C. trachomatis. The presence of serum chlamydia antibodies was significantly higher in subjects with a past history of genital chlamydial infection than in those without a past history of infection (P<0.01). However, there was no difference in the results of the SDA assay between subjects with or without a previous infection.
Thus, although serum chlamydia antibodies are generally measured at public health centers, tests for detecting C. trachomatis should also be used.
在日本的公共卫生中心，沙眼衣原体抗体的血清水平通常用于对接受性传播疾病咨询和检测的患者进行衣原体感染的诊断，而大多数诊所则进行病原体检测。本研究的目的是评估一种检测沙眼衣原体的试验的实用性，并将其与公共卫生中心的血清衣原体抗体筛查进行比较。
采用酶联免疫吸附测定法（ELISA）估计血清衣原体抗体滴度，同时使用包括链置换扩增（SDA）的核酸扩增试验在尿液中检测沙眼衣原体。我们比较了120例患者（64名男性和56名女性）的结果，因为据报道，使用女性尿液样本的方法的敏感性与使用宫颈样本的方法一样高。当IgA和IgG抗体中的一种或两种呈阳性时，血清抗体检测结果被认为是阳性。
抗体检测阳性结果的总体患病率为24.2%（男性为14.1%，女性为35.7%），SDA方法的患病率为7.5%（男性为3.1%，女性为12.5%）。两种检测的一致性率为81.7%，kappa统计量为0.35（95%CI，0.10 - 0.59）。在使用SDA检测法检测出沙眼衣原体阳性的9名受试者中，1人有血清衣原体IgA抗体，6人有IgG抗体，1人两种抗体都有，1人没有抗体。另一方面，在沙眼衣原体检测为阴性的111名受试者中，只有8人有衣原体IgA抗体，5人有IgG抗体，8人两种抗体都有。这些结果表明血清IgA抗体与沙眼衣原体的存在之间没有关联。有生殖器衣原体感染既往史的受试者中血清衣原体抗体的存在显著高于没有感染既往史的受试者（P<0.01）。然而，有或没有既往感染的受试者之间SDA检测结果没有差异。
因此，尽管公共卫生中心通常会检测血清衣原体抗体，但也应使用检测沙眼衣原体的试验。
