There were more cases of sexually transmitted diseases (STDs) in 2015 than in any previous year, according to new data from the Centers for Disease Control and Prevention (CDC).<br />More than two million cases of chlamydia, gonorrhea and syphilis were reported in 2015.<br />"We have reached a decisive moment for the nation," Dr. Jonathan Mermin, director of CDC's National Center for HIV/AIDS.<br />"STD rates are rising, and many of the country's systems for preventing STDs have eroded," he said.<br />"We must mobilize, rebuild and expand services -- or the human and economic burden will continue to grow."