Routine Syphilis Screening in Pregnancy of Nakornping Hospital, Chiang Mai Province: Traditional and Reverse Algorithms

Abstract

Syphilis  is  a sexually  transmitted infection  caused by  Treponema   pallidum.   The

infection  during pregnancy  can cause  adverse outcomes  such  as fetal death, preterm birth, low birth weight and congenital syphilis. Two algorithms are currently used for syphilis diagnosis: traditional and reverse algorithm. This study aimed to compare the results from three syphilis screening methods consisting of the routine practice of Nakornping Hospital, Chiang Mai Province, traditional and reverse algorithms. The descriptive cross-sectional  study was conducted in 600 pregnant women in Nakornping Hospital during June and December 2016. Participants’ sera were tested by using rapid plasma reagin (RPR) and commercial immunochro- matography strip tests. The results of 3 algorithms were compared. The inconsistent results were confirmed by the fluorescent treponemal antibody absorption procedure assay (FTA-ABS). Four pregnant women (0.67%) were diagnosed as syphilis infection. The reverse algorithm detected all syphilis infected-patients while routine screening by Nakornping Hospital and the tradi- tional algorithm detected only 2 cases which revealed 50% detection error in traditional algorithm. These results demonstrated that the reverse algorithm should be considered  an algorithm of choice for syphilis screening in pregnant women.