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But patient-to-patient transmission can occur
Infection control professionals dealing with the rare but real risk of a case of Creutzfeldt-Jakob Disease (CJD) are finding that the legitimate medical issues can quickly become engulfed by a swirl of misinformation, media hype, and public panic.
"There have been some very ridiculous and scientifically unsound responses made in the emotional heat of this," says Richard T. Johnson, MD, a CJD expert and professor of neurology, microbiology, and neuroscience at Johns Hopkins University in Baltimore.
For example, even though there is little definitive proof that CJD can be spread by blood, the decision has been made by many blood banks to notify recipients of blood from donors whom later developed CJD, Johnson says. Such a case occurred in his area, and he was asked to advise and console a distraught pregnant woman who had been notified that she had been infused a pint of blood from a donor who subsequently developed CJD. Johnson set the patient’s mind at ease, assuring her that donated blood has not been established as a route of transmission for CJD.
"That is not even a known risk," he says. "In, fact all of the evidence is against any transmission by blood transfusion of a sporadic disease. So it is only a theoretical risk. It’s a little like being hit by a meteor."
In that regard, one recent study that took an exhaustive look at the blood transmission question concluded, "no human cases have yet been causatively linked to blood transfusion. . . . Animal transmission suggests that the disease has the potential to be transmitted through blood. However, human epidemiologic evidence only indicates that if blood transmission occurs, it is likely rare."1
However, transmission risks cannot be dismissed outright because there are clear cases where CJD has spread from patient-to-patient on surgical instruments.
"There have been transmissions from human-to-human, but only with physicians acting as the transmitters," Johnson says. "You need to transfer cells. It has occurred with corneal transplants, dural grafts, growth hormone made from human pituitaries, and surgical instruments. It is transmissible only under those circumstances so far as we know."
Rare but recurrent, the traditional so-called "sporadic" form of CJD occurs throughout the world. It is a rapidly progressive, invariably fatal neurodegenerative disorder that is assumed to be caused by abnormal prion proteins. The estimated annual incidence in the United States is about one case per million people. The vast majority of CJD patients usually die within one year of illness onset, but the incubation period prior to that may be as long as 20 years.
CJD is classified as a transmissible spongiform encephalopathy (TSE), a group that includes other prion diseases in humans and animals. In about 85% of patients, CJD occurs as a sporadic disease with no recognizable pattern of transmission. A smaller proportion of patients (5% to 15%) develop CJD because of inherited mutations of the prion protein gene, according to the Centers for Disease Control and Prevention.2
Though rare, sporadic CJD raises major infection control questions — including possibly notifying exposed patients — because nosocomial transmission, as Johnson noted, has occurred via surgical instruments and other means. Iaterogenic (pro-vider-to-patient) transmission of CJD has been reported in more than 250 patients worldwide, according to the CDC. Though it has been considered infectious since the mid-1960s, the absence of a screening test for CJD and its prolonged incubation period have thwarted many an epidemiological conclusion about this elusive disease. Indeed, some researchers argue that many more CJD cases of unknown etiology may actually have a history of previous hospitalization and surgery, suggesting that a greater level of nosocomial transmission may be occurring than has traditionally been thought.3
Complicating these legitimate concerns is a confusion among the public and even some medical professionals about two other, different TSE prion diseases. The first is bovine spongiform encephalopathy (BSE) — mad cow disease — which has emerged dramatically in cattle in the United Kingdom. There is increasing evidence that some humans who consumed animals with BSE are developing a new variant Creutzfeldt-Jakob disease (nvCJD) in the United Kingdom and other European nations. (See related story, p. 120.) In contrast to the sporadic form of CJD, the new variant strain predominantly strikes younger people (median age at death: 27 years).
It is important to stress, however, that neither BSE in cattle nor nvCJD in humans has been detected in the United States. The cases grabbing local headlines stateside are due to the ongoing appearance of the traditional, sporadic CJD. But the widespread publicity about mad cow disease — attendant with images of slain livestock and fears that humans who unknowingly consumed infected animals will develop the variant strain — has changed the nature of sporadic CJD cases in the United States.
"There is so much concern about this new variant CJD that a lot of people do not realize that regular CJD occurs," says William Schaffner, MD, professor and chairman of preventive medicine at Vanderbilt University Medical Center in Nashville, TN. As a result, when word gets out that a hospital is dealing with a case of CJD, there may be immediate speculation among the media and public that the mad-cow-derived variant strain has found its way to U.S. soil. Near hysteria and morbid fascination comingle in much the same way they did a few years ago when "flesh-eating bacteria" (Group A strep) was the darling of the tabloid media.
For example, Schaffner recounts a recent case of CJD at a hospital in his area that got transformed via the rumor mill into what would have been the first case of nvCJD in the United States. "A rumor began circulating that this person had traveled to England," he says. "The [disease] got transformed into new variant CJD. That got into the local media, and we had to put out that fire."
Thus, explaining the disease to patients, public, staff, and media appears to have become a given for ICPs dealing with CJD. With the potential for a circus atmosphere, Schaffner suggests that ICPs have a policy in place before they see their first case. "Usually it is the OR staff that hear about it [first]," Schaffner says. "Then they should alert infection control, and you can work together to make sure that the policy is actually implemented. If you have a policy in place, that is easier than having to create one in 24 hours."
ICPs develop model CJD policy
Though several U.S. hospitals dealing recently with CJD cases have been reticent to discuss the disease, clinicians at a Colorado hospital have decided to share their experience and resulting policy with readers of Hospital Infection Control. A key aspect of the policy is tracking surgical instruments and taking steps to ensure they are not reused until CJD is ruled out. (See related story and policy, pp. 122; 123.)
The situation began last November when a patient with no apparent neurological symptoms of CJD (i.e., suggestive of progressive dementia, muscular contractions) came to Exempla Saint Joseph Hospital in Denver for a brain biopsy to rule out vasculitis. Three weeks later, the pathology report came back.
"It indicated CJD, which surprised everyone," says Kristin Burkett, senior director of quality at Exempla. "So at the time we got the pathology report back, we quarantined those instruments that were used in that surgery. Because we have a very detailed surgical-instrument-tracking system, we were able to pinpoint the specific surgical instruments that were used in that procedure and pull those instruments out of service."
Unfortunately, the instruments had been reused on six subsequent patients in the interim between the biopsy and the diagnosis. Those had to be considered possible exposures because traditional sterilization methods may not effectively kill CJD in brain and dura mater left on instruments.
"You have to use something that destroys protein tertiary structure — agents like Clorox," Johnson explains, "things that tear up tissues, but unfortunately also tear up the surfaces on expensive surgical instruments."
The Exempla instruments in question were never used on another patient, as the hospital opted to remove all risk by incinerating them.
The six patients, meanwhile, already had been discharged and would have to somehow be told that there was a slight possibility that they could contract a fatal neurological brain disease as a result of their medical care. And if they did, there was nothing they or anybody else could do about it. Before relaying such dire news, Burkett and colleagues wanted to be absolutely sure the pathology report was correct.
"The neurosurgeon was so surprised by the CJD diagnosis that, honestly, we were not sure we believed it when we got the pathology report back," she said. "We thought there might have been a mistake. We didn’t want to take a chance of informing those patients if there was any possibility that that was not truly the diagnosis. So we sent the specimen off for a second opinion and waited to get a second pathology report back."
The diagnosis was confirmed and plans to notify the patients were discussed with the hospital ethics committee. After a lot of discussion, the decision was made to have their individual primary physicians inform the patients. "We decided that [the physicians] had the personal relationships with their patients to be able to be in the role of communicating [this]," says Colleen Casaceli, BSN, MPH, CIC, infection control coordinator at Exempla. "I think it did go very well as a result. We were very concerned about handling that the best way possible and creating the least amount of irrational fear as we could."
The patients met with their primary care physi-cians in March to be informed of the situation. While transmission has occurred between surgical patients, the likelihood of such an occurrence appears to be exceedingly low based on the limited data, Johnson stresses. Moreover, there is no treatment for the patients in any case.
Nevertheless, informing patients in such cases has now become routine in the United States, he adds. While Exempla cited ethical reasons in informing the patients, Johnson says the patient notification trend with CJD also is being driven by legal advice to avoid or minimize liability, he says.
"This is legal terrorism," Johnson says. "The fact is there is nothing you can do about it. It is unwanted, unnecessary information. But people are being notified . . . not to [medically] do anything about it, but as a liability issue."
Another concerning development is reports of surgeons who refuse to operate on CJD patients and pathologists who refuse to perform autopsies on their bodies, Johnson says. "Surgeons have transmitted it [via instruments], but they have never gotten it. They are not the ones at risk; their patients are at risk."
To avert such concerns, Casaceli led the effort to educate staff about CJD. "It is very rare so they wanted some information about just what the disease was. Everybody is still subject to a lot of media [coverage] about mad cow disease. There is a lot of misconception about what [CJD] disease is — what we were actually encountering vs. the new variant CJD."
Indeed, the hospital’s efforts to clarify the distinct differences between sporadic CJD, nvCJD, and mad cow disease were not completely successful with one local newspaper. When the article appeared reporting the hospital’s CJD situation, it ran with an accompanying photograph, Burkett sighed, "of a cow."
1. Ricketts MN, Cashman NR, Stratton EE, et al. Is Creutzfeldt-Jacob disease transmitted in blood? Emerg Infect Dis 1997; 3:155-163. Web site: http://www.cdc.gov/ncidod.
2. Centers for Disease Control and Prevention. Web site: http://www.cdc.gov/ncidod/hip/INFECT/CJD.htm.
3. Collins S, Law MG, Fletcher A, et al. Surgical treatment and risk of sporadic Creutzfeldt-Jakob disease: A case-control study. Lancet 1999; 353:693-697. n