(AP) -- Public and military health officials say they're trying to identify people in at least five states who had close contact with an organ donor who died of rabies or with the organ recipients because they might require treatment.
A 20-year-old Air Force recruit from North Carolina who died of rabies in Florida had symptoms of the disease but wasn't tested before his organs were transplanted to four patients, one of whom died of rabies nearly 18 months later, federal health officials said Friday.
The three other organ recipients are getting rabies shots and haven't displayed any symptoms. Doctors at the Centers for Disease Control and Prevention declined to speculate on their chances for survival.
"This case is so unique and atypical that we cannot make predictions," said Richard Franka, acting leader of the CDC's rabies team.
Dr. Matthew Kuehnert, director of the agency's Office of Blood, Organ, and Other Tissue Safety, said investigators don't know why doctors in Florida didn't test the donor for rabies before offering his kidneys, heart and liver to people in Florida, Georgia, Illinois and Maryland.
The man in Maryland who received the transplant died in late February. The Defense Department said he was an Army veteran who had transplant surgery at Walter Reed National Military Medical Center in early September 2011.
A rabies test after a death can take four hours once the tissue reaches a lab in Atlanta, New York or California, Franka said. That's precious time: A donated kidney remains viable for less than 24 hours; other organs last for less than six.
The donor had seizures and encephalitis - a brain inflammation that can be caused by rabies - but those symptoms can also be caused by a variety of bacterial, viral and other more common conditions.
"Rabies is very unusual, and it can look like a lot of different things," Kuehnert said. "I personally can't say I would have been able to make the correct diagnosis had I been there, without knowing what I know now."
Federal rules require organ banks to disclose "any known or suspected" infectious conditions that might be transmitted by the donor organs.
"We don't know exactly what was communicated, but from what I understand of the patient workup, they did not find any evidence of an infection," Kuehnert said.
The donor died in September 2011 at an undisclosed Florida medical facility. Medical workers believed at the time that he died from encephalitis of unknown origin, Florida Department of Health epidemiologist Dr. Carina Blackmore said.
He was a North Carolina resident who was training to become an aviation mechanic in Pensacola, Fla., when he got sick, Defense Department spokeswoman Cynthia O. Smith said.
A rabies expert unconnected to the case, Dr. Rodney Willoughby of Milwaukee, said the three other recipients have a strong chance of surviving because they haven't shown any symptoms.
Their identities haven't been publicly disclosed.
In North Carolina, state health officials recommended vaccine for at least one of the donor's relatives, said Carl Williams, the state's top public health veterinarian. He said fewer than five family members from North Carolina visited the man while he was hospitalized in Florida. Officials are looking for others who might have had contact with the donor or recipients in those states and in Georgia, Illinois and Maryland.
"What generally happens in human rabies patients that are hospitalized is that there is a lot of close contact, not only from health care workers but from close family because the patient is going to die," Williams said. The disease can be transmitted by saliva from a kiss or tears wiped away, he said.
Rabies attacks the nervous system and is transmitted between humans in saliva. In transplant cases, it can be transmitted through transplanted nerves in the organs.
The CDC hasn't determined how the donor got the raccoon rabies virus that killed him and the Maryland man. Investigators found the virus in their brain tissue.
The Illinois transplant was performed at Northwestern Memorial Hospital in Chicago.
The CDC said there has been just one other reported instance of rabies transmission by transplanted solid organs, a 2004 case in which all four recipients died after receiving tissue from an infected donor. There have been at least eight instances of rabies transmission through transplanted corneas, CDC spokeswoman Barbara Reynolds said.
She said rabies is diagnosed as the cause of just one to three deaths per year in the United States.
The Maryland death was announced Tuesday by state health officials. It was the state's first rabies death since 1976. State Public Health Veterinarian Katherine Feldman said doctors suspected before the man died that he had rabies, and they knew about his kidney transplant, but considered a rabies-infected kidney to be a remote possibility.
The raccoon rabies virus has a typical incubation period of one to three months, although there have been other cases of longer incubation periods, the CDC said. In the United States, only one other person is reported to have died from a raccoon-type rabies virus.
After the four deaths in 2004, the U.S. Department of Health and Human Services created a committee within the federal Organ Procurement and Transplantation Network to look specifically at disease transmission. Last year, the government published guidelines for evaluating organ donors with central nervous system infections, such as encephalitis. If evidence suggested such an infection, "caution should be considered," the guidelines said.
The Health Resources and Service Administration, which oversees the transplantation network, said Friday that there is no government-approved test to quickly screen organ donors for rabies. Therefore, donation professionals must review the person's medical and social history to assess potential risks.