Every 8 minutes, child protective services substantiates, or finds evidence for, a claim of child sexual abuse, according to RAINN.

While this statistic is unsettling, we also know that early intervention — even before an episode of abuse occurs — works, and it can make a tremendous difference in a child’s life.

This early action, stopping child sexual abuse before is starts, is the focus Elizabeth Letourneau’s TEDMED talk — and it’s also a professional mission that she’s working to realize.

Letourneau is the founding inaugural director of the Moore Center for the Prevention of Child Sexual Abuse at Johns Hopkins Bloomberg School of Public Health, and she her 18-minute talk takes a close look at how initiatives that target juvenile sex offenders can play a key role in preventing future offenses.

This public health approach is necessary—and needed, according to Letourneau, who is a trained clinical psychologist. “Child sexual abuse is a 100% preventable public health problem,” she says. “There is no reason for us to wait for sexual abuse to happen before we intervene.”