Urging the doctors to take strict measures before transplants, health officials said it was the first reported instance of the two viruses being spread simultaneously by a transplant.
The federal Centers for Disease Control and Prevention (CDC) and health officials are investigating the Chicago cases.
The event may trigger off widespread changes in testing methods since the most commonly used tests until now fail to detect viral diseases if they are performed too early in the course of the infection.
Dr. Matthew Kuehnert, who oversees organ safety at the CDC told the NY Times, "There are important policy implications."
"Clearly, the organ transplant community is going to think about the issues raised by this, and we look forward to being involved in those discussions," he added.
According to reports appearing in the Chicago Tribune, two patients were infected at the University of Chicago Medical Center, and one each at Rush University Medical Center and Northwestern Memorial Hospital.
The transplants were coordinated by an organization called the Gift of Hope, in Elmhurst, Ill. The suspected organs involved in transplants are most likely the kidneys, liver and either the heart or lungs. Only four organs, and no other tissue, were taken from the donor.
The transplant from an adult donor took place in January, and he died in an Illinois hospital "three days after traumatic injury," the University of Chicago said. Neither the donor's age nor sex was disclosed.
