The number of people diagnosed with a sexually transmitted disease has increased in Connecticut as well as across the country, data from the Centers for Disease Control and Prevention (CDC) reports. Though experts note that some of the increase is due to better screening, they are concerned about an actual rise in cases and attribute that to more casual sex through hookup apps and an increase in unprotected sex. Nationwide, more than 2 million cases of chlamydia, gonorrhea and syphilis were reported in 2016, the highest number ever, with chlamydia making up the majority of cases. The annual Sexually Transmitted Disease Surveillance Report, released in late September, found that a total of 1,598,354 cases of chlamydia were reported in 2016, a 4.7 percent increase over 2015. Gonorrhea cases increased by 18.5 percent to 468,514, and syphilis increased 17.6 percent to 27,814 cases. In Connecticut, 14,028 cases of chlamydia were reported, 759 more than in 2015, a 5.7 percent rise.