Four months after a Maryland man died from rabies, an investigation into the source of the fatal case indicates the individual received the virus via a kidney transplant that occurred 18 months prior to his death.
The report, published in the Journal of the American Medical Association, suggests that rabies transmitted by this route may have a long incubation period, and that although solid organ transplant transmission of infectious encephalitis is rare, further education to increase awareness is needed.
The rabies virus causes a deadly inflammation of the brain and can be transmitted through tissue or organ transplantation. Throughout the world, an estimated 55,000 people die from the disease every year, mostly through dog bites. In the United States, however, an average of just two human rabies deaths were reported between 2000 and 2010, the majority of which were caused by bats, according to the report.
Raccoons, on the other hand, are the creature most frequently reported rabid animal in the nation, and, the researchers found, the animal behind the virus that ultimately killed the man.
In analyzing the medical records of the organ donor and recipient in addition to conducting tests on both individuals' tissues and cerebrospinal fluid, the researchers found that, in retrospect, the kidney donor's symptoms prior to death were consistent with rabies, though the presumed diagnosis at the time he died was the foodborne illness ciguatera poisoning. Not until an autopsy was conducted did physicians realize the true cause of death.
Furthermore, interviews with family members revealed the donor had sustained at least two raccoon bites for which he did not seek medical care. Sure enough, rabies virus antigen was detected in archived autopsy brain tissue collected from the donor.
Upon discovering this, health officials immediately contacted three other individuals who received organs from the same individual, though none have exhibited any signs or symptoms consistent with rabies or encephalitis. In fact, rabies virus neutralizing antibodies were detected in their serum, an analysis showed.
Going forward, the authors argue, the event should serve as a warning for increased precaution in regards to safe organ donation.
"This transmission event provides an opportunity for enhancing rabies awareness and recognition and highlights the need for a modified approach to organ donor screening and recipient monitoring for infectious encephalitis," they wrote, adding that the "investigation also underscores the importance of collaboration between clinicians, epidemiologists, and laboratory scientists."