Questions and Answers - Human Rabies Due to Organ Transplantation, 2013

Summary

The Centers for Disease Control and Prevention (CDC) and Maryland Department of Health and Mental Hygiene have confirmed that a patient who recently died of rabies in Maryland contracted the infection through organ transplantation done more than a year ago. The patient was one of four people who had received an organ from the same donor. CDC laboratories tested tissue samples from the donor and from the recipient who died to confirm transmission of rabies through organ transplantation.

The Maryland Department of Health and Mental Hygiene initiated an investigation after the organ recipient died, which led to the rabies diagnosis. The investigation revealed that the organ recipient had no reported animal exposures, the usual source of rabies transmission to humans, and identified the possibility of transplant-related transmission of rabies, which is extremely rare.

The organ transplantation occurred more than a year before the recipient developed symptoms and died of rabies; this period is much longer than the typical rabies incubation period of 1 to 3 months, but is consistent with prior case reports of long incubation periods. CDC’s preliminary laboratory analysis indicates that the recipient and the donor both had the same type of rabies virus—a raccoon type. This type of rabies virus can infect not only raccoons, but also other wild and domestic animals. In the United States, in the past 50 years, only one other person is reported to have died from a raccoon-type rabies virus.

How common is it for organ recipients to get diseases from their donors?

While organ transplantations are often life-saving procedures, illness and death rarely can occur from transmission of undetected infections from donors. Diseases that have been unknowingly transmitted through transplants include a wide array of viruses, bacteria, and parasites despite extensive donor screening.

The Health Resources and Services Administration (HRSA) oversees organ transplantation through the Organ Procurement and Transplantation Network (OPTN), established by Congress under the National Organ Transplant Act of 1984. In late 2004, a new OPTN policy required organ procurement organizations and transplant centers to report to the United Network for Organ Sharing (UNOS) suspected donor-derived disease transmissions (infections and malignancies). Reporting is increasing, but the rate of transmission of infectious diseases that are unrecognized at the time of transplantation is still not well understood. It is estimated that about 1% of all transplant recipients are suspected to have a transplant-transmitted infection. Death associated with infectious disease transmission is more unusual, but has been reported, including in this most recent rabies transmission.

Has anyone else ever gotten rabies from an organ donor before? What happened in that case?

In 2004, CDC confirmed the first reported cases of rabies transmission through solid organ transplantation. Although rabies transmission had occurred previously through cornea transplants, this was the first report of rabies transmission via solid organ transplantation. The organ donor had undergone routine eligibility screening, including laboratory testing. One of the organ recipients died during transplant surgery, and the other three recipients died later of rabies. When questioned after the donor’s death, friends of the donor indicated the donor had recently reported being bitten by a bat.

A similar rabies transmission through organ transplantation occurred in Germany in 2005. Six recipients received organs or tissues from a donor with rabies. Two recipients receiving donor corneas were not infected after their grafts were removed. Recipients who received lung, kidney and combined kidney and pancreas organs died. The liver recipient had been previously vaccinated against rabies and survived.

Are organs routinely screened for rabies when they are donated in the United States? What diseases are organs screened for in the United States?

All potential organ donors in the United States are screened and tested to identify if the donor might present an infectious risk. Organ procurement organizations are responsible for evaluating the suitability of each organ donor. Donor eligibility is determined through a series of questions posed to the person consenting to organ donation, physical examination of the donor, and infectious disease testing, including screening for HIV and hepatitis B and C viruses. Transplant centers are prohibited from accepting and transplanting organs from donors infected with HIV.

Could rabies screening have detected infection in this donor?

After the transmission cluster in 2004, many organ procurement organizations added a screening question about rabies exposure. In this instance, the screening did not identify a risk for rabies. The recent transmission of a rare rabies virus infection through an organ donor underscores the fact that screening prior to organ transplantation cannot always detect every possible donor-derived infection. Fortunately, the risk of rabies transmission remains very low as this is only the second known organ donor with rabies in the United States (the first was identified in July 2004). Laboratory testing needs to be carefully considered for accuracy and ability to obtain results in time.

How was the donor exposed to rabies?

It is believed that the donor was exposed to rabies through contact with an infected animal. CDC, in conjunction with state health departments and other public health collaborators, is actively working to learn more about and ultimately confirm the nature of the donor’s exposure.

What’s the status of the other organ recipients?

The three other recipients are being evaluated by their healthcare teams. These individuals are being monitored closely and are showing no signs of rabies infection.

When administered in a timely fashion, rabies postexposure prophylaxis (anti-rabies shots that consist of immune globulin and anti-rabies vaccination) is highly effective at preventing infection. Post exposure prophylaxis has been recommended for the other three organ recipients.

If I had an organ transplant a year or two ago, could I have an infection?

The vast majority of transplant-transmitted infections show evidence of infection soon after the transplantation. If patients are concerned about infection after organ transplantation, they should contact their transplant team.

How long does it take for rabies to make someone sick?

Typically, the time from exposure to rabies virus until clinical symptoms appear (also known as the incubation period) ranges from 1 to 3 months. In the only known previous cluster of rabies transmission through organ transplantation in the United States, all 4 recipients died or developed rabies within 30 days of transplantation. In the recent case, the organ transplantation occurred approximately 16 months prior to the onset of symptoms and death of the recipient. Incubation periods exceeding one year are very rare, making this one of the longer rabies incubation periods recorded.

The type of rabies virus found in both the donor and the recipient was of raccoon origin, which is only found in North America. In the United States, only one other person has ever died from this type of rabies virus. It is unknown, however, whether the route of infection, type of virus, or immune suppression drugs may be factors in changing the time course for infection in the transplant setting.

How is raccoon rabies different from dog or bat rabies?

Many types of the rabies virus exist and are often associated with a particular animal. Examples include raccoon rabies and bat rabies virus variants. The type of rabies caused by dogs, which is now eliminated in the United States, is another example. Each type of rabies can be transmitted to other animals. As an example, it is possible for a bat with bat rabies to infect a dog that then bites a human, exposing the person to bat rabies even though there was no exposure to a bat. Any mammal can get rabies and potentially transmit it through bites, but in the United States there are only a few major reservoirs (such as raccoons, skunks, bats, and foxes) that maintain circulation of virus and are a source of infection for humans and other mammals.

Human rabies cases resulting from raccoons are very rare. In 2003, the first death associated with the raccoon rabies virus variant was reported. In this case, the animal that caused the human exposure was ultimately unable to be identified. The animal exposure of the donor associated with the most recent rabies tran