Case report indicates rabies infection linked to organ transplant from a skunk-scratched donor — Evidence Review

A recent case report describes a Michigan man who died from rabies following a kidney transplant, with the infection traced to an organ donor scratched by a skunk; such donor-derived rabies transmission is extremely rare. Previous studies largely corroborate the risk of rabies transmission through organ transplantation, though all agree these events are infrequent but nearly always fatal (1, 2, 3); see the detailed case in the CDC's Morbidity and Mortality Weekly Report.

• Related studies confirm that rabies can be transmitted through solid organ transplantation, with several documented clusters of fatal cases in different countries, highlighting diagnostic and screening challenges for unusual pathogens (1, 2, 3, 4, 5, 8, 9).
• Timely post-exposure prophylaxis (PEP) for exposed recipients is critical and may prevent disease if administered before symptoms, as demonstrated in some cases where recipients remained asymptomatic after prompt intervention (3, 7).
• The new case underscores ongoing diagnostic barriers—particularly when donor exposure histories are unclear or symptoms are attributed to other conditions—echoing themes from prior research about the need for improved donor screening and heightened clinical suspicion in cases of unexplained encephalitis (1, 3, 4, 9).

Study Overview and Key Findings

Rabies is known for its almost universal fatality once symptoms develop, and transmission through solid organ transplantation is exceedingly rare. However, the Michigan case is noteworthy both for its tragic outcome and for the investigative efforts that linked the infection to an organ donor’s prior wildlife exposure. The case highlights persistent vulnerabilities in donor screening processes when exposure circumstances are subtle or unrecognized, as well as the challenges clinicians face in diagnosing rabies in immunosuppressed transplant recipients.

Property	Value
Organization	Ohio Department of Health, U.S. Centers for Disease Control and Prevention
Authors	Nicoletta Lanese
Population	A man who received a kidney transplant
Methods	Case Report
Outcome	Rabies infection linked to organ transplant
Results	The man died from rabies infection after kidney transplant.

Literature Review: Related Studies

To contextualize the new findings, we searched the Consensus paper database, which includes over 200 million research papers. The following search queries were used to identify relevant literature:

1. rabies transmission organ transplant
2. kidney transplant rabies case studies
3. animal bites rabies infection outcomes

Related Studies Table

Topic	Key Findings
How often does rabies transmission occur via organ transplantation?	- Documented cases of rabies transmission through organ transplantation are rare but have resulted in fatal outcomes for multiple recipients (1, 2, 3, 4, 5, 8, 9).
	- Donor exposure to rabid animals is frequently unrecognized or misattributed, leading to missed opportunities for prevention (1, 4, 5, 9).
What are the outcomes and prevention strategies for transplant recipients exposed to rabies?	- Rabies is almost universally fatal once symptoms begin, but timely post-exposure prophylaxis may prevent disease in transplant recipients if administered before symptom onset (2, 3, 7, 8).
	- Some recipients who received prompt PEP after notification of donor infection have survived, underscoring the critical role of rapid response (3, 7).
What are the diagnostic and screening challenges for rabies in transplant medicine?	- Rabies is difficult to diagnose in donors and recipients due to non-specific symptoms and lack of routine screening, especially when exposure history is incomplete (1, 4, 9).
	- The need for improved vigilance and standardized protocols for screening donors with unexplained encephalitis or neurological decline is emphasized (3, 7, 9).
What is the immune response to rabies vaccination in transplant recipients?	- Kidney transplant recipients are capable of mounting an immune response to the rabies vaccine, suggesting potential utility of vaccination if exposure is suspected (6).

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How often does rabies transmission occur via organ transplantation?

Rabies transmission through solid organ transplantation is rare but has been reported in several clusters, often resulting in fatal outcomes for recipients. These cases highlight the difficulty in identifying infected donors, especially when animal exposures are unreported or symptoms are attributed to other causes.

• Multiple case reports have documented fatal rabies transmission from a single donor to several recipients, often involving kidneys, liver, and other tissues (1, 2, 5, 8, 9).
• Donor animal exposures—such as bites or scratches—are frequently unknown or not disclosed at the time of organ procurement, increasing the risk of transmission (1, 4, 5, 9).
• Rabies transmission events have occurred in various regions, including the United States, Germany, China, and elsewhere, indicating a global relevance to the issue (2, 4, 5, 7, 8, 9).
• The new Michigan case adds to a small but significant body of literature indicating that while rare, donor-derived rabies remains a persistent risk in transplantation medicine (1, 2, 3, 4, 5, 8, 9).

What are the outcomes and prevention strategies for transplant recipients exposed to rabies?

Rabies is nearly always fatal once symptoms appear, but post-exposure prophylaxis (PEP) can be lifesaving if administered before symptom onset. Some transplant recipients have survived after timely intervention, underscoring the importance of rapid notification and treatment.

• Once clinical rabies develops, survival is exceedingly rare, with most recipients succumbing rapidly after symptoms manifest (2, 8, 9).
• In cases where exposed recipients received prompt PEP after diagnosis in another recipient or donor, some patients remained asymptomatic and survived, emphasizing the need for swift action (3, 7).
• The empirical “Milwaukee protocol” has been attempted in symptomatic recipients, but with limited and inconsistent success (2).
• The new case illustrates the fatal consequences of delayed recognition and lack of PEP in organ recipients, reinforcing the value of prompt identification of at-risk individuals (2, 3, 7, 8).

What are the diagnostic and screening challenges for rabies in transplant medicine?

Diagnosing rabies in both donors and recipients is challenging due to non-specific symptoms and the rarity of the disease in many regions. Incomplete exposure histories and lack of routine screening often lead to missed cases.

• Donors who develop acute progressive encephalitis of unknown origin may be misdiagnosed or have their symptoms attributed to chronic conditions or drug use (1, 4, 9).
• Rabies should be considered in cases of unexplained neurological decline, especially when donors come from or have visited rabies-endemic regions (3, 7, 8, 9).
• Protocols for screening donors with undiagnosed encephalitis are not uniformly implemented and represent an area for potential improvement (3, 7, 9).
• The Michigan case, where the donor’s skunk scratch was not initially known, exemplifies these diagnostic gaps and the need for careful history-taking and consideration of rabies in atypical presentations (1, 4, 9).

What is the immune response to rabies vaccination in transplant recipients?

There is evidence that kidney transplant recipients can generate an immune response to rabies vaccination, suggesting that PEP may be effective in this population if initiated promptly after exposure.

• A study of a kidney transplant recipient found that rabies vaccination elicited a measurable immune response, indicating that immunosuppressed patients may still benefit from PEP (6).
• This supports the practice of administering PEP to exposed transplant recipients as soon as possible, even if they are immunocompromised (3, 7, 8).
• The literature, while limited, suggests that vaccine efficacy may be adequate in this group, but further research is needed to optimize dosing and timing (6).
• The Michigan case did not involve PEP after transplantation, but future cases may benefit from immediate prophylaxis if donor risk is identified (3, 6, 7).

Future Research Questions

Despite advances in transplantation medicine and rabies prevention, significant gaps remain in donor screening, recipient management, and understanding of immune responses in immunosuppressed hosts. Further research is essential to improve safety and outcomes for transplant recipients.

Research Question	Relevance
What are the most effective screening protocols for detecting rabies in organ donors?	Improved screening could reduce the risk of donor-derived rabies transmission by identifying at-risk donors before transplantation. Current protocols may miss cases with atypical presentations or incomplete histories (1, 3, 4, 9).
How effective is post-exposure prophylaxis in immunocompromised transplant recipients exposed to rabies?	Understanding PEP efficacy in transplant recipients is crucial, as immunosuppression may alter vaccine response. Limited studies suggest benefit, but optimal protocols remain unclear (3, 6, 7, 8).
What clinical features should prompt rabies testing in donors with unexplained encephalitis?	Identifying distinguishing symptoms or histories could aid in earlier recognition and prevention of rabies transmission via transplantation (1, 3, 4, 9).
Can standardized risk assessment tools reduce rabies transmission from organ donors to recipients?	The development and implementation of structured tools may help transplantation teams systematically evaluate donor risk, as suggested by recurring diagnostic challenges (3, 7, 9).
How does rabies incubation period vary in transplant recipients compared to the general population?	Better understanding of incubation times could inform monitoring and PEP strategies for recipients exposed to potentially infected donor organs (3, 7, 9).