Syphilis is caused by the syphilis bacteria, usually transmitted through sexual contact.

The first sign of syphilis is a small sore, called a chancre (SHANG-kur). The sore appears at the spot where the bacteria entered your body. While most people infected with syphilis develop only one chancre, some people develop several of them. The chancre usually develops about three weeks after exposure. Syphilis tests are used to screen for and diagnose syphilis. Screening tests for syphilis include a Rapid plasma reagin (RPR), a syphilis blood test that looks for antibodies to the syphilis bacteria. Antibodies are proteins made by the immune system to fight foreign substances, such as bacteria.

• A positive test results when the Syphilis Test detects antibodies in a blood test. No antibodies mean there has been no exposure to the bacteria.
• Untreated, syphilis causes partial paralysis, numbness, the gradual onset of blindness, and even dementia.
• Syphilis is entirely treatable with antibiotics.