That's the million-dollar question, and there are likely several factors at play. One issue, as previously reported by PopSci, is that the immense stigma surrounding STIs prevents people from getting tested, getting treated, and disclosing infections to partners. Recent reports actually show that teens are waiting longer to have sex, but CDC data does suggest that young people, along with gay and bisexual men, are using condoms less reliably. An increase in unprotected oral sex among young people may also be a factor.
But one thing is clear: The above factors are not to blame for our current predicament. According to a report published by the CDC in February, the uptick in heterosexual syphilis transmission seems closely tied to recent drug use epidemics, and could potentially be addressed in tandem by offering better access to counseling and healthcare. The CDC also reports that more than half of local STD-prevention programs have experienced budget cuts in recent years, resul