Diagnostic dilemma: Man caught rabies from organ transplant after donor was scratched by skunk

The patient: A man in Michigan

The symptoms: The man received a left kidney transplant in an Ohio hospital, and about five weeks later, he began experiencing tremors, weakness in his lower extremities and urinary incontinence, as well as confusion.

What happened next: About a week after these initial symptoms emerged, the man was hospitalized with additional health problems, including fever and difficulty swallowing. He also developed hydrophobia, or an irrational fear of water. Once hospitalized, he required breathing support with a ventilator.

The diagnosis: The man's doctors suspected that his signs and symptoms indicated a rabies infection, so they consulted the Ohio Department of Health and U.S. Centers for Disease Control and Prevention (CDC) about the case. Various clinical samples from the patient were sent to the CDC for testing and ultimately came back positive for rabies RNA, the genetic material of the virus, as well as antibodies against the virus.

The treatment: Within a week of being hospitalized, the patient died of his infection. Once a rabies infection is established, there is no effective cure available. There are only about 30 reports of people surviving symptomatic rabies in the medical literature, and doctors can't yet reliably replicate this outcome. As such, rabies is nearly always fatal.

(People who suspect they may have been exposed to rabies — for example, after being bitten by an animal — can be treated with anti-rabies antibodies or vaccines to help prevent the virus from triggering an infection in the first place. This preventative treatment is very effective.)

What makes the case unique: This man's rabies infection — the first reported in Michigan in about 15 years — was suspected to be potentially linked to his organ transplant, according to a report of the case. Investigators had ruled out direct animal exposure as the source of the infection.

Upon learning about the suspected infection, the CDC and state- and local-level partners launched an investigation into possible contamination of the donor kidney. The donor had been from Idaho and the investigators got in touch with the donor's family.

It turned out that "in late October 2024, a skunk approached the donor as he held a kitten in an outbuilding on his rural property," the report says. "During an encounter that rendered the skunk unconscious, the donor sustained a shin scratch that bled, but he did not think he had been bitten. According to the family, the donor attributed the skunk’s behavior to predatory aggression toward the kitten."

Five weeks after being scratched, the donor began experiencing symptoms consistent with rabies, including confusion, difficulty swallowing, hallucinations and a stiff neck, a family member said. He then fell unconscious at home and didn't wake up, though he was resuscitated and hospitalized. He was declared brain dead and removed from life support five days later.

Notably, hospital staff members who treated the donor were initially unaware of the skunk scratch and attributed his symptoms to chronic conditions, not to rabies. That said, they took various clinical samples from the patient that the CDC then retroactively tested for the virus.

A biopsy from the donor's right kidney tested positive, but there wasn't a big enough sample from the left kidney to test. Nonetheless, this supported the idea that the donor kidney was likely the source of the Michigan man's rabies.

"This was the fourth reported transplant-transmitted rabies event in the United States since 1978," the case report noted. "However, the risk for any transplant-transmitted infection, including rabies, is low." In short, this chain of events is very unlikely, and hospitals follow extensive protocols to safeguard against transplanting infected organs into patients.

For more intriguing medical cases, check out our Diagnostic Dilemma archives.