VRE hits Canada via U.S. transfers
February 1, 1997 8 minutes read
VRE hits Canada via U.S. transfers
Communication in a shrinking global village
Vancomycin-resistant enterococci (VRE) may be becoming a nosocomial "export" from the United States, as infection control professionals in Canada are tracing some of their first VRE cases to patients transferred or readmitted from U.S. facilities.
Carrying the threat of heightened mortality in immunocompromised patients and the risk that it may transfer its drug resistance properties to Staphylococcus aureus VRE has increased exponentially in U.S. hospitals throughout the 1990s.1 (See related stories in Hospital Infection Control, July 1994, pp. 89-94; October 1993, pp. 133-136.)
Despite the upsurge in the United States, the first documented nosocomial outbreak in Canada did not occur until late 1995. (See related story, p. 26.) In addition, a VRE prevalence sample conducted last year by Canadian health officials in 27 sentinel hospitals found a rate of only one positive VRE culture per 1,000 high-risk patients tested.
But all indications are that a follow-up VRE survey slated for April of this year will reveal an increasing presence of the pathogen, says Shirley Paton, MN, chief of nosocomial and occupational infections at the Laboratory Center for Disease Control in Ottawa.
"Our numbers to this point have been extremely low, but since we did that survey we are aware of four other hospitals that have had major [VRE] outbreaks," she says. "I think we are just on the verge of saying VRE has arrived, and it is arriving with a vengeance."
The situation is being taken seriously enough in many Canadian hospitals that a patient history of recent admission to a U.S. hospital warrants screening for the enteric pathogen via rectal swab.
"The vast majority of our sentinel sites are actively swabbing anyone that is transferred in from a U.S. hospital for VRE and MRSA [methicillin-resistant S. aureus]," Paton says. "It doesn’t really matter where they come from in the States it’s seen as endemic."
The policy at Mount Sinai Hospital in Toronto, for example, calls for asking incoming patients whether they have been hospitalized anywhere outside of Canada in the last six months. Those who have are screened and placed in isolation pending culture results, explains Karen Green, RN, CIC, infection control coordinator at Mount Sinai.
"Our personal experience has generally been with patients who have been in the hospital in the U.S. for some reason, whether they have been wintering there and have been admitted or have elected to go there for some type of procedure and then have come back as direct transfers," she says.
Still, the U.S. connection may become less important if VRE spreads within Canadian hospitals. Another motivation for increased screening of incoming patients is that Canadian hospitals also are reporting a striking upsurge in MRSA, a somewhat surprising phenomenon since that pathogen has enjoyed an endemic presence in many U.S. facilities since the 1980s.
"MRSA is becoming a major problem for us at the moment and this is 15 years after the fact," Green says. "We have been very aggressive for a long time, but we have a few strains now that are really causing us some problems."
Indeed, several distinct MRSA strains including one traced to a patient from India have been tracked as they spread out across Canada. The dramatic inroads being made by both MRSA and VRE illustrate how pathogens can suddenly appear on the epidemiologic radar and move from hospital to hospital, says Allison McGeer, MD, director of infection control at Mount Sinai and Princess Margaret Hospitals in Toronto, and a member of several Canadian committees and national organizations trying to develop health care policy to meet the threat.
Feels like watching the Titanic sink’
"It moves into your hospital on a patient from a hospital where it is endemic, spreads within your hospital, and then bounces from your hospital to other hospitals," she says, noting that tracking the steady increase of what began as few sporadic VRE cases in Canada "sometimes feels like watching the Titanic sink."
McGeer and laboratory colleagues have identified 22 different clones of VRE in hospitals in Ontario, including 10 that have been traced to back to a patient transferred from a U.S. hospital.
"In none of these cases was the receiving hospital notified about the patient being positive," she says. "These are all direct transfers. In these cases we are not talking about people who went home and them came back into the hospital, although that is equally a problem."
Some of the U.S. hospitals in question none of which were identified by Canadian officials were apparently not screening patients for VRE colonization. That may have been in some cases because they had accepted an endemic level of the pathogen and were no longer looking for it, McGeer notes.
U.S. hospitals don’t screen routinely for VRE
"VRE is particularly bad at the moment because hospitals have such different attitudes toward it," she says. "We had a cluster here at Sinai [due to] a patient who was transferred from a large northeastern medical center to us directly and was positive when he came in. Their answer was they don’t have a problem. Sure, they have it, but is not a problem, and they don’t screen for it."
The Centers for Disease Control and Prevention has left the VRE transfer issue for individual states to resolve, and there have been problems particularly between hospitals and nursing homes. (See related story in Hospital Infection Control, June 1995, pp. 69-74.) The CDC Hospital Infection Control Practices Advisory Committee guidelines also do not recommend routine screening of patients for VRE, but do note that those wishing to do so can reduce the costs of testing by targeting efforts to those patients "who have been admitted from a facility, such as a tertiary care hospital or a chronic-care facility where VRE are known to be present."2
As a result, most U.S. hospitals do not routinely screen patients for VRE on discharge or admission , but if the patient is known to be colonized or infected prior to transfer the information is routinely added in the discharge summary, according to an infection control professional at a New York City hospital.
"It’s usually part of the information with the patient, but we have had some problems here with patients being transferred in with [VRE] from nursing homes," says Kathleen Jacob, RN, BSN, CIC, nurse epidemiologist at Columbia Presbyterian Medical Center which is not one of the facilities implicated by Canadian officials.
While noting that knowingly transferring a VRE patient without informing the other institution would be "devious," Jacob says most of the U.S. hospitals in question probably are not aware that the patients transferred to Canada are VRE-colonized. While the protocol of screening incoming admissions may work for the limited number of transfers coming into Canadian hospitals, it would probably not be practical or affordable for U.S. hospitals to adopt a policy of routinely screening all patients on discharge or transfer, she adds.
"There are patients we have with VRE who are clearly identified and are on isolation during their entire hospitalization, so by reading their discharge summary, you would be able to identify who we know have these organisms," she says. "We can’t guarantee that we are identifying everybody with these organisms, but I think we are identifying most of them."
Regardless, the situation is not limited to hospitals in the Northeast or those otherwise close to the Canadian border, Green says.
"From my knowledge of talking to other [Canadian ICPs], it is not limited to any state our case came from Ohio," she says. "I know of cases that have come in from Florida and New York state."
Spread to four other patients
The transfer from Ohio which occurred in February of last year was complicated by the fact that the patient came in right before a weekend and VRE colonization was not recognized until the following Monday, Green says.
"At that point in time we put him on strict isolation precautions for his VRE and we screened patients in the two hospital units that he had been on," she says.
Two additional VRE-colonized patients were found, and screening was extended to two adjacent units due to a lot of cross-over staffing between health care workers. The resulting tally was four additional patients colonized with the same strain of VRE one in each of the four units, Green says. The route of transmission was most likely on the hands of health care workers or via shared equipment like stethoscopes or blood pressure cuffs, she says.
Though all five of the VRE cases were only colonized rather than clinically infected with the pathogen, Green and colleagues implemented aggressive measures to prevent further spread of VRE within the facility. Measures adopted at the facility included designated equipment for VRE patients and barrier precautions for staff that include gowns and double-gloving.
"We use double-gloving because of the concern for environmental contamination," she says. "As soon as you finish your contact with the patient, the outer pair of gloves comes off for handling other things in the room. We aim to minimize transmission from the patient to all of the environmental surfaces that we touch in the room."
As a result of the case, Green urges ICPs in hospitals in both the United States and Canada to alert other facilities that a patient being transferred is known to have a multidrug-resistant organism or is coming from a facility where such pathogens are endemic. Likewise, patients colonized or infected with such pathogens should be educated to alert caregivers of their medical history when later readmitted, she adds.
"We were lucky we took a very aggressive, all-or-nothing approach to our first case," she says. "And we ended up only having the four additional cases and stopped our outbreak within 10 days. We have not conceded MRSA, and we are not conceding VRE."
In a sense, Canadian hospitals face a situation similar to many U.S. facilities that have still not seen many cases of VRE a decision of whether they should attempt rigorous screening and control measures or try to contain the pathogen only after it appears in their hospital
"The frustrating thing about VRE is that is not inevitable," McGeer says. "You can control it and it is cost-effective to control it. There is no doubt that efforts put into detecting and eradicating VRE early will pay off in terms of costs. The problem is that they cost money up front. If you are in a VRE-free area, at the moment you are unlikely to get VRE evolving in your area, but it will be imported. If you want to detect it and keep it out of your area, you have to have a system for picking up the VRE that is coming in."
[Editor’s note: As a follow-up to this report, look for an update on the VRE-patient transfer situation in the United States and a review of the latest state guidelines in an upcoming issue of Hospital Infection Control.]
References
1. Centers for Disease Control and Prevention. Nosocomial enterococci resistant to vancomycin United States, 1989-1993. MMWR 1993; 42:597-599.
2. Hospital Infection Control Practices Advisory Committee. Recommendations for preventing the spread of vancomycin resistance. Infect Control Hosp Epidemiol 1995; 16:105-113.
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