The continuing threat of syphilis in pregnancy.
Syphilis in pregnancy continues to be a worldwide threat to mothers and their fetuses, and in recent years has been increasing in prevalence. The purpose of this short review is to address current issues in the diagnosis and management of syphilis complicating pregnancies. Maternal syphilis infections and congenital syphilis appear to be increasing in both high and low resource settings. Treponema pallidum ssp. pallidum, the causative spirochete of syphilis, remains one of the few human infectious pathogens that has not been successfully cultured, making identification difficult and research in targeted antimicrobial therapies challenging. Fortunately, syphilis remains sensitive to penicillin, which remains the foundational therapy for this infection. Patients with syphilis and significant penicillin allergies remain a specific challenge in treatment. Of concern is the emergence of T. pallidum resistant to macrolides such as azithromycin. This will limit options in patients with penicillin allergies, and potentially contribute to suboptimal treatment. During pregnancy, penicillin is the only known effective treatment for congenital syphilis, and pregnant patients with penicillin allergy should be desensitized and treated with penicillin. Research focusing on protein expression of the genome of T. pallidum may lead to more accurate screening and diagnosis and development of novel antibiotic therapies. Obstetric and pediatric providers, public health organizations, and governments should recognize the re-emergence of syphilis globally and in their local healthcare environments. Screening of all pregnant patients with robust treatment and follow-up represents the most effective method to reduce congenital syphilis currently available.