Syphilis is a growing threat to gay and bisexual men with and without HIV. Syphilis rates have also climbed recently in women with and without HIV.
Syphilis can spread through anal, vaginal, or oral sex. Oral sex is not "safe sex" when it comes to preventing syphilis.
Having HIV infection raises the risk of syphilis up to 7 times. Other syphilis risk factors include (1) anal sex without a condom, (2) oral-anal sex ("rimming"), (3) using drugs (including meth and Viagra) during sex, and (4) having many casual sex partners.
A person may not notice the first signs of syphilis because the sores it causes are not painful and look like sores caused by other diseases. These sores may appear on the penis (Figure 1), but they may be hidden from view inside the anus, rectum, or vagina.
The second stage of syphilis may be marked by rough, red, or reddish-brown spots that are not itchy (Figure 2 and 3). Other signals may include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue -- but these signals also occur with many other diseases.
The bacterium that causes syphilis can quickly get inside the brain and cause headache, fever, stiff neck, blurred or lost vision, sensitivity to light, hearing loss, or facial weakness.
Because syphilis can go unnoticed so easily, sexually active people with a high risk of syphilis (see 3 above) should get tested for syphilis regularly.
Detecting syphilis is important because it's usually easy to cure with two shots of penicillin. But if syphilis is not treated, it can get much worse.
If you learn that you have syphilis, it is very important to tell your sex partners or let health authorities contact them so they can be tested and treated.
No one becomes immune to syphilis. Infected people who get cured can get syphilis all over again.