Congenital syphilis is caused by transplacental transmission of spirochetes. Transmission is highest (60-90%) in untreated maternal primary or secondary syphilis.
In those infected, symptoms present either early (<2 years but mostly < 3 months) or late (>2 years).
Reference: Long, S., Pickering, L. (2008). Principles and Practice of Pediatric Infectious Diseases. 3rd ed. Philadelphia: Churchill Livingstone. Chapter 182, page 932-933.
Previously published: 30/01/15