Syphilis has been around for much of human history. Its results were depicted by artists brilliant and incompetent, a heroic nurse gave it to Nazi troops, and it was at the center of one of the worst failures of medical ethics in American history. But, as of 2000, it was down to just six thousand cases, and the CDC thought we could wipe out syphilis entirely. Sixteen years later, it’s back and it’s nasty.

The jump is striking. Cases have tripled from the 1990 low of 6,000. Worryingly, a few of those were cases of ocular syphilis (yes, you can get syphilis in your eyes) and congenital syphilis, where the disease is passed from mother to child. While it’s not as bad as it was back in the day, the rise is particularly scary.

Why the increase? The short answer is people are using condoms less, especially people who use apps to hook up, and it’s harder to get tested as Congress cuts the budgets of STD clinics across the nation. Syphilis is easily treated, but you have to know you have it first, and there’s a pretty good chance if you get it, you won’t even notice.

Syphilis has evolved from the days when it would rot your nose off and eat your brain. Now a small, easily missed sore is the only early sign you’ve got an infection, if you even find one in the first place. Or you could skip right to the secondary signs, like fever, sore throat, and headache. Then it basically just sits in your body, waiting to infect others and ruin your health in ten to thirty years by attacking your heart or nervous system.

So, how do you keep syphilis from going all Middle Ages on your health? One, wear condoms, which you should be doing anyway. And two, get tested. It’s a quick test, the treatment is equally fast, and you’ll be doing your part to keep syphilis out of our bodies. And if all that won’t do it, look at this horrifying Wikipedia entry and ask yourself if that’s something you want to see in the mirror.

