CDC: Rabies risk rare, but PEP for needlestick
Undiagnosed case leads to four transplant deaths
In light of the recent rabies outbreak due to transplant of infected organs, the Centers for Disease Control and Prevention (CDC) is reiterating that exposure to feces, urine, blood, or other body fluids is not considered a risk for rabies transmission.1 The rabies virus cannot survive on surfaces in the environment for any substantial period of time.
However, postexposure prophylaxis (PEP) for rabies is recommended following a needlestick injury, because infectious nerve material could be contained in the bore of the needle following tissue penetration in a rabies patient. Thus the CDC recommendation is related to the possibility of nerve tissue exposure rather than blood exposure.
The organ donor, an Arkansas resident, had undergone routine donor eligibility screening and testing. Rabies testing is not part of the routine screening process. Lungs, kidneys, and liver were recovered and later transplanted on May 4 into four recipients, all of who have died. No other organs or tissues were recovered from the donor. The CDC worked with health officials from Texas, Alabama, Oklahoma, Arkansas, and other public health partners to evaluate potential contacts of the transplant recipients and the donor to determine who needs shots. No other cases are expected to be found in the cluster, which has raised questions about whether rabies could infect the blood supply.
"There is not a presence of a virus in blood, so there is not a risk of transmitting rabies by blood transfusions," says Mitchell Cohen, MD, director of CDC’s coordinating center for infectious diseases.
"The way the disease progresses is that following an exposure — let’s say a bite occurred on the hand — the virus would reproduce and would travel up the nerves and eventually infect the central nervous system. And so the virus then could come back and involve the organs by again traveling down the nerves, but it doesn’t enter the vascular system. It isn’t associated with a viremia or presence of the virus in the blood. So there isn’t any evidence that that would occur in individuals who are infected with this disease."
There have been previous cases of rabies infections via corneal transplants, but the spread of the disease via such routes is exceedingly rare.
The cluster associated with solid organ transplants should prompt no significant changes in public health policy.
"Last year there were a little over 25,000 organ transplants," notes Daniel Hayes, MD, an organ transplant expert at United Network for Organ Sharing in Richmond, VA.
"If you extrapolate that over years, there have been hundreds of thousands of corneas and organ transplants with only — prior to this, one documented case of transmission [via corneal transplants]. I don’t think that such a rare event should trigger any kind of widespread panic or reaction to do testing on a disease that is so infrequent," he adds.
Q&A for staff
In the wake of the transplant outbreak, the CDC posted the following answers to the most common questions by health care workers:
Question. I handled rabies-infected organs as part of the procurement or transplant procedure — am I at risk for rabies?
Answer. Health care workers who may have handled an organ to be transplanted are at low risk for exposure because the virus is contained within the nerve tissue of the organ. Organ manipulations that might generate sprays or splashes containing nerve tissue theoretically pose a risk for exposure to the rabies virus. The use of standard precautions (i.e., gowns, gloves, and masks with goggles or face shields when indicated) would prevent such exposure; rabies PEP would be recommended in this situation only if standard precautions were not used and an exposure occurred.
Question. I took care of one the rabies patients after or shortly before they developed clinical signs of rabies — am I at risk for rabies?
Answer. There are no known cases of rabies transmission to health care workers caring for patients with rabies. In the United States, PEP is recommended for health care workers who have been exposed to a patient’s saliva, nerve tissue, or cerebrospinal fluid in the 14 days before or anytime after illness onset. Possible routes of exposures include percutaneous and mucocutaneous entry of the rabies virus, such as through a wound or nonintact skin or via mucous membrane contact.
Question. What are some circumstances in health care settings in which rabies exposure may have occurred?
Answer. Health care workers who had an open wound, nonintact skin, or mucous membrane contact with a patient’s saliva, nerve tissue, or spinal fluid or who experienced an injury with a contaminated needle or other sharp device related to patient care should receive rabies PEP. Specific examples where PEP would be recommended include the following:
- cut or puncture with a solid sharp (e.g., scalpel injury during surgery or autopsy or cut from bone fragment that penetrates glove and skin);
- mucous membrane contact with saliva (e.g., spray, splash, or hand-to-eye or hand-to-mouth contact of saliva to mucous membranes in the absence of personal protection).
1. Centers for Disease Control and Prevention. Rabies in Transplant Recipients: Healthcare Settings. Atlanta; July 2004. Web: www.cdc.gov/ncidod/dvrd/rabies/ques&ans/q&a_transplants_healthcare.htm.