The investigation's new phase involves the federal Centers for Medicare and Medicaid Services, which oversees organ procurement programs and hospitals countrywide.
The stakes are high: If the agency finds any mishandling and the hospitals do not comply with any demands for corrective action, the hospitals could face penalties. The worst would be being ousted from the Medicare program participation, meaning a loss of crucial federal revenue.
The case disclosed this week also is the first time HIV and hepatitis have been spread simultaneously from one donor to transplant recipients, public health officials say.
While Medicare officials generally contract with local authorities to investigate hospitals, this time the agency has sent officials to Chicago to assist investigators from Illinois' Department of Public Health, said Jan Tarantino, director of the agency's division of continuing care providers.
"We're taking some extra steps ... because this is potentially a very serious situation," she said Thursday.
Hospital and public health officials have called the case a tragedy, but emphasize that the risk of getting any disease from transplanted organs is less than 0.01 percent.
Tarantino said officials from her agency last week visited the group that procured the organs, Gift of Hope Organ & Tissue Donor Network. This week they started questioning authorities at the three hospitals, Northwestern Memorial Hospital, Rush University Medical Center and the University of Chicago Medical Center.
"We're looking at the circumstances surrounding the donor and the four recipients and checking to make sure that all the notifications" took place, Tarantino said.
None of the hospitals has said publicly what patients were told, citing doctor-patient confidentiality. They also have declined to identify the donor, the patients and what organs they received, citing privacy concerns.
Gift of Hope officials have said they followed proper procedures before the January transplants by notifying all three hospitals that the donor had engaged in high-risk behaviors.
Attorney Thomas Demetrio filed a petition Thursday in Cook County Circuit Court on behalf of an infected female patient, asking officials to keep the University of Chicago and Gift of Hope from destroying or altering any records involving the donation.
Gift of Hope Organ & Tissue Donor Network in Elmhurst and the University of Chicago both knew the kidney donor was high-risk and did not inform the patient, Demetrio said.
University of Chicago spokesman John Easton responded in an e-mail: "We believe we follow guidelines, and of course with the patient's consent we will provide necessary records and documents, as is consistent with our open process."
Gift of Hope did not immediately respond to requests for comment.
Demetrio described his client as a single Chicago-area woman in her 30s who had rejected an organ from another potential donor "because of his lifestyle."
"She's really a mess right now," Demetrio said of the woman. "She's still in shock."
The patient, identified in court documents with the anonymous name Jane Doe, received a kidney transplant at the University of Chicago Hospitals on Jan. 9, Demetrio said.
The woman had been told the donor was a healthy young man, her attorney said. But on Tuesday, hospital officials disclosed to the woman that he was actually high-risk, a 38-year-old gay man, Demetrio said. She was told she had HIV and hepatitis on Nov. 1, he said.
"The (organ) procurement group knew, the hospital knew, but the most important person did not know" initially that the donor was high-risk, he said.
"The people that dedicate their lives to these transplant surgeries, they're just great people, but they need to bring the patient into the mix and let them make an informed decision," he said.
U.S. Centers for Disease Control and Prevention guidelines say that gay men who are sexually active should not be used as organ donors unless the patient is in imminent danger of death.
Federal guidelines say patients are supposed to be notified about the possibility of HIV infection from a high-risk donor even if tests show the donor does not have the virus.
Standard tests for HIV and hepatitis antibodies showed the donor did not have those diseases. Authorities say the donor probably acquired the infections a few weeks before death, too soon for the tests to detect antibodies.
A newer, costlier test that is not widely available can detect the virus earlier but was not done in this case. That has led public health officials to press for more widespread use of the newer test.
"Hopefully in the future it can be the norm," said Dr. Susan Gerber, chief medical officer for Chicago's Department of Public Health.
Gerber said her office is working with the CDC, "trying to find out what happened." That includes examining the circumstances surrounding when the patients were first tested for HIV.