Bizarre teen trends have been horrifying parents for generations, but health officials are warning that a vampire-inspired biting fad could be dangerous, not to mention disgusting.

Teenagers obsessed with the “Twilight” vampire saga, or those simply fascinated with fangs, reportedly have been biting each other — hard – and then licking or sucking the blood.

“These are kids who think they are real vampires,” said Dr. Orly Avitzur, the medical advisor to Consumers Union, the agency that publishes Consumer Reports magazine.

Avitzur said conversations with teens and sessions spent trolling vampire-related teen Web sites convinced her that the trend was taking hold. Indeed, groups like “I drink blood,” a category at www.experienceproject.com, and “I want to be a vampire” at the site www.43things.com are filled with apparent posts from young people with a yearning for blood.

Such talk alarms medical experts, who warn about the dangers of blood-borne diseases such as hepatitis and HIV, as well as the risk of nasty infections. Typically, 10 to 15 percent of human bites wounds become infected.

Do you know any Twihards who’ve turned vampire obsession into a real-life drama?