ATLANTA - A Georgia graduate student fighting a rare flesh-eating bacterial infection she contracted after being injured in a zip-line accident is now able to sit in a chair for hours at a time, her father told Reuters.

"When the doctors put Aimee up in that chair, their expectations were to give her an hour," Andy Copeland wrote in a Facebook posting Thursday. "Five hours later, Aimee decided it was time to lie down. Had she been running an Olympic marathon, I think Aimee would have experienced a record-breaking, gold-medal moment."

The struggle to save 24-year-old Aimee Copeland from necrotizing fasciitis -- a bacterial infection that can destroy muscles, skin and tissue -- has been chronicled by her father on Internet postings.

Copeland, a student at West Georgia University, slashed her calf when the zip-line snapped May 1 along the Little Tallapoosa River near Carrollton, Georgia. Emergency room doctors closed the wound with 22 staples and released Copeland, but she was diagnosed with the infection after her conditioned worsened.

Aimee remains in critical condition, Barclay Bishop, spokeswoman for Doctors Hospital in Augusta, said told Reuters Thursday.

A 1996 report from the U.S. Centers for Disease Control and Prevention estimated there were 500 to 1,500 cases of necrotizing fasciitis annually in the United States, with about 20 percent of them fatal. The National Necrotizing Fasciitis Foundation has said that estimate is probably low.

Earlier this week, Aimee's father reported on Facebook, reported Reuters, that she was able to breathe on her own without a ventilator. The latest improvement, sitting up in a chair, was prompted Tuesday when Aimee asked to go out in the hall with a nurse.

Donna Copeland, however, asked a nurse if Aimee could sit up in a chair and doctors agreed. There were fewer tubes attached to Aimee at the time because doctors had temporarily taken her off a dialysis machine to see how her body would respond. Also, she was not connected to the ventilator, Andy Copeland wrote.

Source: Reuters; Facebook; Huffington Post