The most prevalent mode of transmission is by sexual contact; infection by other means is possible, but its occurrence depends upon an open wound or lesion to permit invasion of the organisms. A person with syphilitic sores has an increased chance of contracting AIDS from an infected partner. An infected mother can transmit the disease to her fetus; 25% of such pregnancies end in stillbirth or death of the infant, and another 40% to 70% will result in a baby with congenital syphilis, which, if untreated, can progress to late-stage syphilis and cause serious damage to the brain and other organs.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.