The resurgence of syphilis among pregnant women in southern Chile.

Abstract

National rates of HIV, gonorrhoeae and syphilis have increased in Chile in recent years, but it is not known if syphilis among pregnant women (PW) is also escalating. To explore syphilis rates among PW in a southern Chilean region and to describe clinical features of mothers and offspring. We selected PW with positive VDRL or T. pallidum micro-he-magglutination (MHA-TP) reactive tests, referred to a high-risk obstetrical pathology center between 2011 and 2019. Clinical information of mothers and their offspring was obtained from their medical records. Syphilis rates among PW increased from 0.4 to 7.2 per 1,000 live births in the reference center from 2013 to 2019, along with a national and regional increase in both sexes. Twenty-nine cases of PW with syphilis were identified with a median age of 28 years (interquartile range 23-32). Seventeen percent had a history of drug abuse, and 14% had previous sexually transmitted diseases. In seven cases (24%), the diagnosis occurred at delivery. Three percent of patients had a primary syphilis, 14% a secondary syphilis, 24% an early latent syphilis, and 59% a latent syphilis. All cases except one case were treated with benzathine penicillin G and the remaining with erythromycin due to allergy suspicion. Penicillin desensitization was required in two cases (7%). Treatment timing was inadequate in 10 cases (34.5%). Of 19 patients with available serological follow-up, 10 (53%) showed a significant decrease in VDRL titers (≥ 2 dilutions) and two cases had re-infection. Two patients (7%) had an abortion, two had congenital syphilis (7%), and six had premature births (21%), totaling 35% of adverse-pregnancy outcomes. Resurgence of syphilis among pregnant women is happening in southern Chile and is associated to adverse-pregnancy outcomes.