Condom use has dropped sharply since 2010 among a large share of students at the University of Minnesota, and sexually transmitted infections such as chlamydia and gonorrhea are on the rise.
In a new survey, 52 percent of students said they used a condom the last time they had vaginal intercourse, down from 60 percent in a survey five years ago. The share who said they used a condom for oral sex or anal sex has risen slightly, but remains far too low, U health officials said.
"Due to a combination of behavioral, biological and cultural reasons, sexually active young adults are at increased risk for acquiring sexually transmitted infections," or STIs, the study said.
The new numbers leave condom use at the lowest level in recent memory, said Dave Golden, director of public health and communications at the U's Boynton Health Service. "This is the first time we've ever seen this," he said.
The study did not factor in students who were married or in domestic partnerships.
While the causes remain unclear, Golden speculated that students may be dropping their guard because of improved treatments for infections such as HIV, which has become less of a death sentence than it once was.
But the reasons, he said, matter less than the risks.
"There's been a lot of people making a lot of guesses, and it's just guesswork," he said. "We're just trying to get students to use condoms, and we want that number to go up."