Four organ transplant patients, including two who received their procedures at the University of Chicago Hospitals in January, were infected with HIV and hepatitis C as a result of the procedures, the hospital announced last week. The disease was not detected in the organ donor’s blood because the donor had likely been infected shortly before death, and the body had not yet started producing the antibodies that the test detects and that indicate HIV’s presence, doctors said.

While HIV transmission from an organ donor has not occurred since 1985, and experts estimate there is only a 0.01 percent chance of an organ recipient contracting any serious illness, the four new cases have sparked controversy about the organ donation process. This was the first known instance of recipients receiving both HIV and hepatitis C from a donor, according to the Centers for Disease Control (CDC).

According to John Easton, director of communications for the U of C Medical Center, there are over 97,000 Americans waiting to receive organs and fewer than 30,000 people will receive one, due to a shortage of donations. As a result, organ-procurement organizations accept organs from donors who are considered high risk—people who engage in behavior that increases their risk of contracting HIV and other diseases.

According to the CDC’s guidelines for high risk behavior, “the risk to the recipient of not performing the transplant is deemed to be greater than the risk of HIV transmission and disease.”

These same guidelines also suggest that doctors notify their patients of the donor’s history and the potential risks involved. Because of federal privacy laws, the U of C Hospitals will not reveal what organ recipients were told about the donor.

However, a lawyer for one of the patients revealed this week that she was not notified that her organ came from a high-risk donor.

The case has raised questions about whether or not physicians should be required to reveal all risk information to a potential organ recipient.

Some doctors say that the decision does not lie with the patient, while others believe that organ recipients should be aware of all risks so that they can make informed decisions.

“Our physicians are heartbroken,” said Dr. Mike Millis, section chief of transplantation at the University of Chicago Medical Center, through a hospital spokesperson. “The rewards of our profession come from knowing that transplants save thousands of lives every year. We are dealing with a challenging and very complex process. This situation has heightened the determination of the transplant community to find new and better ways to make a safe system even safer. It would be a tragedy for a patient desperately in need of an organ to feel inhibited from seeking a transplant. Thousands of lives are saved year after year because transplantation works.”

All organs undergo a rigorous screening test used to identify HIV-infected donors. But the test screens for antibodies that may not appear until 22 days after someone has been infected.

In the Chicago case, the donor was infected shortly before death, and the infection did not show up in the test. Nucleic acid testing can detect antibodies within 12 days of HIV contractions, but there are few centers in the U.S. that do such testing, and keeping a donor’s organs viable for longer than 24 hours is not an option.