Americans are contracting sexually transmitted diseases, or STDs, at higher rates than ever before, according to a new report from the Centers for Disease Control and Prevention. The report, released at the National STD Prevention Conference in Washington, D.C., said that 2.3 million cases of chlamydia, gonorrhea, and syphilis were reported in 2017. “We are sliding backward,” Jonathan Mermin, director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, said in a press release. Gonorrhea diagnoses increased 67 percent, doubling among men and with notable, concerning spikes among women. Syphilis cases are up 76 percent, dominated by men who have sex with other men. And chlamydia was the most common STD reported, with 1.7 million cases reported in 2017, primarily among 15- to 24-year-old women. One big reason for the spikes, especially in gonorrhea, is antibiotic resistance. “We expect gonorrhea will eventually wear down our last highly effective antibiotic, and additional treatment options are urgently needed,” Gail Bolan, director of CDC’s Division of STD Prevention, said in a press release.