Berkowitz K, Baxi L, Fox H E
Department of Obstetrics and Gynecology, Sloane Hospital for Women, Columbia Presbyterian Medical Center, New York, NY 10032.
Am J Obstet Gynecol. 1990 Sep;163(3):975-7. doi: 10.1016/0002-9378(90)91107-n.
The prevalence of congenital syphilis is rapidly rising in several areas of the United States. Efforts to control the disease depend on the effectiveness of established screening strategies and treatment of infected pregnant women. False-negative test results hinder these efforts and leave the fetus at risk for acquiring congenital syphilis. Recently we encountered four cases of false-negative syphilis serologic results in women who gave birth to infants with congenital syphilis. The false-negative results were caused by the prozone phenomenon. The prozone phenomenon, seen during primary and secondary syphilis, occurs because a higher than optimal amount of antibody in the tested sera prevents the flocculation reaction typifying a positive result in reagin tests. Serum dilution is necessary to make the correct diagnosis. We recommend that for any pregnant woman with apparently negative syphilis serologic results in whom fetal compromise of unknown etiology exists, particularly nonimmune hydrops, nontreponemal testing should be repeated using serum dilutions to prevent a missed diagnosis of syphilis. We further recommend serum dilution as a routine procedure for all pregnant women in areas of high syphilis prevalence.
在美国的几个地区，先天性梅毒的患病率正在迅速上升。控制该疾病的努力取决于既定筛查策略的有效性以及对感染孕妇的治疗。假阴性检测结果阻碍了这些努力，并使胎儿有感染先天性梅毒的风险。最近，我们遇到了4例梅毒血清学结果为假阴性的病例，这些产妇所生婴儿患有先天性梅毒。假阴性结果是由前带现象引起的。前带现象在一期和二期梅毒期间出现，是因为检测血清中抗体量高于最佳量，阻止了反应素试验中典型阳性结果的絮凝反应。血清稀释对于做出正确诊断是必要的。我们建议，对于任何梅毒血清学结果明显为阴性但存在病因不明的胎儿受损情况（尤其是非免疫性水肿）的孕妇，应使用血清稀释重复进行非梅毒螺旋体检测，以防止漏诊梅毒。我们还建议在梅毒患病率高的地区，将血清稀释作为所有孕妇的常规程序。
