A patient alleges in a lawsuit filed Monday in federal court in Philadelphia that a medical practice co-owned by Lancaster County's coroner discriminated against him and his family because he has HIV.

The plaintiffs - identified as the patient, using the pseudonym Husband Jones, and his wife and daughter - say that after four previous visits, the patient returned Oct. 8, 2013, to Stephen G. Diamantoni M.D. & Associates Family Practice's Quarryville office to get the results of blood work drawn four days before. He was given a letter that said that, on his previous visit, "you used the bathroom and apparently left a large amount of blood all over the sink, walls, and floor," and that he had 30 days to find another physician. "Unfortunately, this dismissal stands for all members of your family as well," said the letter, attached to the suit.

The lawsuit says the patient was not bleeding after the blood draw, had done nothing to make himself bleed, and left no blood in the bathroom. "This outrageous story is just a false pretext for denying care to a man because of his HIV status," said Ronda B. Goldfein, executive director of the AIDS Law Project of Pennsylvania, which filed the suit on World AIDS Day on the family's behalf.

The suit says the Americans With Disabilities Act prohibits discrimination against the patient as well as his wife and daughter, neither of whom is infected with HIV. It seeks compensatory and punitive damages, and an order that the practice develop a written antidiscrimination policy and conduct mandatory staff training about HIV.

"The lawsuit is meritless," Diamantoni, the coroner, who co-owns the practice but is not an individual defendant in the suit, said in an interview Monday evening. "We have taken care of AIDS patients since 1985," he said, adding that when he first started practicing, before AIDS medication was available, "I used to make house calls to people who were dying of AIDS."

Diamantoni said he was unable to respond to specific allegations in the lawsuit about blood in the bathroom, referring a reporter to William R. Vollmar, a physician in the practice, who signed the letter dismissing the patient and is named in the suit, along with the patient's doctor, Jeffrey T. Trost. The office where Vollmar and Trost work referred calls to attorney Joseph P. Hofmann.

"He was the first patient of the day. As soon as he left, staff went in and found blood spatters all over the bathroom," Hofmann said Monday night. "No one else could have done it. As a result, the practice decided to terminate this relationship with him."