Facts about congenital syphilis

Syphilis a sexually transmitted disease caused by the bacterium Treponema pallidum subspecies pallidum. It has been called “The Great Pretender”, as symptoms can resemble other diseases.

Syphilis during pregnancy is associated with miscarriage, stillbirth, or infant death shortly after delivery in up to 40% of cases (1). Congenital syphilis occurs when an infected pregnant woman passes syphilis to her fetus during pregnancy. The transmission of syphilis to the infant is more likely to occur in situations where the mother has been infected during the pregnancy, but many cases still occur where the mother was infected prior to the pregnancy (2). There is about a 70% chance of an untreated woman passing syphilis to her fetus (3).

Early congenital syphilis
The signs of early congenital syphilis are usually apparent at 3-14 weeks of age, but in rare cases, there may be no obvious symptoms until 2-5 years of age. A wide range of symptoms are associated with early congenital syphilis including:

  • Inflammation of the umbilical cord, iris of the eye, and bone joints
  • Fever
  • Skin rash and shedding of the skin on the palms and soles
  • Low birth weight
  • Anemia
  • High cholesterol levels at birth
  • Meningitis
  • Jaundice
  • Mental retardation
  • Hair loss
  • Pneumonia
  • Enlarged liver and spleen

Late congenital syphilis
The signs of late congenital syphilis appear after five years of age, but may not be diagnosed until adulthood. A wide range of symptoms are associated with late congenital syphilis including:

  • Bone pain
  • Retinitis pigmentosa (serious eye disease)
  • Peg-shaped upper central incisors
  • Interstitial keratitis (blurred vision, eye pain, light sensitivity)
  • Bone abnormalities (prominent forehead, saddle nose, short upper jaw)
  • Fissuring around the mouth and anus

Diagnosis
Congenital syphilis should be suspected in any child of a mother with syphilis, as there is a 70% chance of transmission in untreated pregnant women (3). However, the wide range of symptoms associated with congenital syphilis often leads to a delayed diagnosis. Furthermore, maternal antibodies to syphilis transferred through the placenta to the fetus can complicate the interpretation of diagnostic tests (4).

Factors that influence newborn treatment decisions include:

  • Diagnosis of syphilis in the mother
  • Syphilis treatment of the mother
  • Presence of clinical, laboratory, or radiographic evidence of syphilis in the newborn
  • Comparisons of maternal and newborn antibody titres

Prevention and treatment
The prevention of congenital syphilis is by far the best option. This is by routine syphilis testing in pregnant women and prompt treatment to prevent the transmission to the fetus. If an infected pregnant woman is untreated there is a 70% risk of passing syphilis to her fetus.

For infected infants, treatment must begin immediately to prevent developmental delays, seizures, and other fatal complications (5). Penicillin is the most effective treatment for infants with congenital syphilis. Additional treatments may include corticosteroids and atropine drops (2).

References
1. Syphilis – CDC Fact Sheet (Detailed). (2017, January). https://www.cdc.gov/std/syphilis/stdfact-syphilis-detailed.htm
2. Congenital Syphilis. (2009). Rare Disease Database: https://rarediseases.org/rare-diseases/congenital-syphilis
3. Sheffield JS, et al. (2002). Congenital syphilis after maternal treatment for syphilis during pregnancy. Am J Obstet Gynecol, 186 (3), 569-573.
4. 2015 STD Treatment Guidelines – Congenital Syphilis. (2015, June 4). CDC: https://www.cdc.gov/std/tg2015/congenital.htm
5. Sexually Transmitted Diseases Treatment Guidelines, 2015. (2015). MMWR, 64 (RR-3).