The odds of catching a sexually transmitted disease are high in South Carolina.

In North Carolina and Georgia, as well.

All 3 states have reported more than 1,800 cases of sexually transmitted chlamydia per 100,000 residents.

With 5 million South Carolinians, that means that up to 30,000 people could have contracted a sexually transmitted disease here.

Research has found that young people are engaging in less sex than older generations did at their age.

But they’re also contracting more sexually transmitted diseases than any other group, and the rates of infection are accelerating.

Last year, combined cases of syphilis, gonorrhea and chlamydia reached an all-time high. Half the reported infections occurring in adolescents and young adults ages 15 to 24.

The reasons for the increases range from reduced access to health care to riskier behavior among those who are sexually active.

The findings are part of the annual Sexually Transmitted Disease Surveillance Report published by the US Centers for Disease Control and Prevention.

Among all age groups, chlamydia grew to more than 1.7 million cases in 2018, an increase of 3% over the previous year.

Gonorrhea rose to more than 580,000 cases, an increase of 5%. And syphilis climbed to more than 115,000 cases, up 13.3%.

The number of HIV diagnoses, tracked separately has been largely stable.

The report reflects only a portion of STDs in the US.

At least 35 different sexually transmitted infections, and most – including herpes and human papillomavirus – aren’t “notifiable,” meaning they aren’t tracked.

The STDs monitored are likely to be undercounted.

The CDC estimates 1 in 4 sexually active adolescent girls has chlamydia or another STD. Up to 80% of females who have chlamydia, a disease that can cause infertility, show no symptoms.

The CDC regards the recent surge in syphilis and gonorrhea to be epidemic.

Until recently, they had been in decline, with syphilis near elimination.