Syphilis

Syphilis is caused by a type of bacteria that spreads from person to person by physical contact during vaginal, anal or oral sex. Sores develop early in the course of syphilis, occurring mainly on the external genitals, vagina, anus or rectum but can also be on the mouth and lips. If left untreated, even if all the signs disappear, syphilis can lead to mental illness, blindness and death. It may have no symptoms, but sometimes a painless, smooth sore on the genital area can be an early sign of disease.

Syphilis infections are treatable and curable with antibiotics, although recently a strain of drug-resistant syphilis has begun showing up in gay and bisexual men.