There has been an alarming jump in the number of syphilis cases in the United States since 2005 according to The Centers for Disease Control and Prevention.
Once almost eliminated in the US, syphilis is increasing among gay and bisexual men.
The rate of cases here is now more than double the all-time low of 2.1 cases per 100,000 back in 2000. Men account for most of the cases. In fact, 91 percent of all syphilis cases were in men in 2013. 84 percent of those cases were in gay or bisexual men, according to the CDC.
"Syphilis is also known as the great imitator it can masquerade as many different diseases," says John Su with the CDC.
Syphilis has declined among women in recent years, driven by declines among black women.
Su says say these findings point to the need for intense efforts to prevent, screen and treat syphilis among men having sex with men.