Health officials confirmed Friday that a Maryland man who received a donated kidney more than a year ago contracted rabies and died from it.
The discovery was "very surprising" and only the second known time rabies has been transmitted through donated organs in the United States. The finding sent Centers for Disease Control and Prevention officers flying to the phones to alert three other people who'd received organs from the same donor. All have been treated and remain healthy.
Rabies is extremely rare in the United States, with only one to three deaths a year. The fact that it took more than a year for the recipient to begin to show symptoms threw investigators off, as usually rabies develops within a month or two.
"We were all saying, 'Wow, how is this possible?'" said Richard Franka, lead of the rabies team at CDC in Atlanta.
Here's what happened: In September of 2011 a Florida man died of encephalitis, an inflammation of the brain. His doctors couldn't find a reason for his illness.
At one point, the doctors thought it might have been some sort of poisoning "because they couldn't come up with a cause. They did a full work-up, they tested for everything they could think of. Even after he died, they sent more tests in and couldn't find a cause," said Matthew Kuehnert, director of CDC's office of blood, organ, and other tissue safety.
The man's family donated his kidneys, liver and heart. One of those kidneys went to a Maryland man. The recipient did fine until last month, when he, too, fell ill with unspecified encephalitis. The Maryland Department of Health and Mental Hygiene started an investigation into the case but couldn't find a cause for his illness. After several weeks doctors started to suspect he perhaps had rabies. Unfortunately, the patient died that same day, before they could begin treatment, Franka said.
Despite the common belief that rabies causes people to act crazy and foam at the mouth, it's actually difficult to diagnose and is easily confused with other pathogens that cause encephalitis, said Franka. CDC laboratory analysis showed that the rabies virus was a raccoon type. In the United States, there's only one recorded case of a person dying from a raccoon-type rabies virus.
Then the question became: How did he get rabies? Investigators went over his life with a fine-toothed comb but couldn't find any indication he had been exposed to wildlife. They knew he'd gotten a donated kidney, "but we were thinking it couldn't be the transplant because of the long incubation period," said Franka. "We were wrong."
Each year in the United States about 28,000 people receive donated organs, said Joel Newman with the United Network for Organ Sharing in Richmond, Va. Only once before in the United States, in 2004, has an infected organ donor passed rabies along to organ recipients, and they all became ill and died very quickly.
Eventually investigators went back to the Florida organ donor's medical history. He, too, had no exposure to wildlife. Finally, when they dug further, they discovered that shortly before he became ill he had been living in North Carolina. Doctors now believe that's where he was infected, though they still don't know how.
The definitive laboratory finding that the Maryland man had, indeed, died of rabies came on March 8. "At that point we started urgently contacting the patients" who had received the donor's other kidney, liver and heart, said Kuehnert. They lived in Florida, Georgia and Illinois and each was immediately started on anti-rabies shots and remain in good health, he said.
All organ donors are run through an intensive screening for diseases that might be transmitted, such as hepatitis, HIV and cytomegalovirus. A detailed medical history is also taken and a physical inspection of the body is done, said Newman.
Rabies is not tested for because it is very difficult to detect before its victim begins to show symptoms, said CDC's Kuehnert. The testing can also take weeks. That's impossible in organ donation where the time window is less than 48 hours and for some organs just six hours.
Rabies is a viral disease often transmitted through the bite of a rabid animal. The virus infects the central nervous system, ultimately causing disease in the brain and death within days of the onset of illness if treatment is not begun in time. In the United States bat bites are the most frequent cause of rabies in humans.