Background: This cluster randomized trial was performed to test whether one-stop service could better prevent congenital syphilis than the conventional antenatal screening service in Mongolia.
Methods: Out of 14 antenatal clinics in 6 districts of Ulaanbaatar, 7 were randomly selected for the one-stop service and the remaining for the conventional service. Intervention clinics provided on-site rapid syphilis testing and immediate treatment for positive cases and their partners. In control clinics, syphilis screening services with routine off-site rapid plasma regain testing and case management were followed. Analysis was intention to treat.
Results: Of 3850 antenatal women recruited in each group, the proportion of syphilis testing at the first visit and third trimester was over 99% in the intervention group and 79.6% and 61.5% in the control group, respectively (P <0.001 for both periods). Correspondingly, syphilis cases detected in the intervention group were 73 (1.9%) and 20 (0.5%) for the first visit and third trimester, respectively, and 27 (0.9%) and 2 (0.08%) in the control group; and 98.9% (92/93) of the detected cases in the intervention group and 89.6% (26/29) in the control group were adequately treated (P = 0.02). The corresponding treatment rates for sexual partners were 94.6% and 55.2% (P <0.001). One congenital syphilis case out of 3632 deliveries in the intervention group, compared to 15 of 3552 in the control group, was diagnosed, a reduction of 93.5% (95% confidence interval, 66.0%–98.6%).
Conclusions: One-stop services increased the detection rate of syphilis, treated more positive women and their partners, and effectively reduced the rate of congenital syphilis.