CDC's failure to encourage HCV follow-up draws fire
January 1, 1996 9 minutes read
CDC's failure to encourage HCV follow-up draws fire
Despite lack of data on HCV, agency criticized for 'copping out'
An infection control advisory committee recently refused to endorse a Centers for Disease Control and Prevention draft position not to recommend any follow-up for health care workers occupationally exposed to hepatitis C virus.
Though the CDC in Atlanta cited a dearth of data on HCV in taking the position, the move was questioned and criticized by members of the Hospital Infection Control Practices Advisory Committee (HICPAC).
"We are not being an advocate for health care workers to assist them in looking for occupationally acquired disease -- we are going to take it on the chin for that," warned HICPAC member Rita D. McCormick, RN, infection control practitioner at the University of Wisconsin Hospital and Clinics in Madison.
At issue is the CDC's reluctance to push its recommendations -- in an unpublished draft document -- beyond the limited data on HCV, which is increasingly being viewed as the most threatening occupational bloodborne pathogen in the hospital setting since HIV. (See related story, p. 4.) Indeed, the debate was somewhat reminiscent of the criticism the CDC received in recent years before adopting a more formal surveillance and reporting system for occupationally acquired HIV infections. While HICPAC members were not advocating such measures for HCV surveillance, the committee will try to add more guidance for hospitals and health care workers before the CDC publishes the paper.
No effective post-exposure prophylaxis
Citing the lack of an effective post-exposure prophylaxis and incomplete data on virtually all aspects of the epidemiology of HCV, the CDC concluded in the draft document that "no recommendation can be made at this time for follow-up of health care workers after occupational exposure to hepatitis C." Slated for publication as a CDC Hepatitis Surveillance Report, the draft will be amended by a HICPAC subcommittee led by panel members McCormick and David W. Fleming, MD, state epidemiologist at the Oregon Health Department in Portland.
In comments after the meeting, Fleming did not rule out trying to amend the document with a recommendation for post-exposure testing for HCV. For example, in a position paper under review, the Society for Healthcare Epidemiology of America (SHEA) in Woodbury, NJ, is considering recommending post-exposure HCV testing of source patients following blood exposures to health care workers. Despite the lack of a post-exposure prophylaxis and limited treatment options, proponents of the SHEA position argue follow-up testing could help clarify whether HCV infections in health workers are occupational or community acquired. (See Hospital Infection Control, August 1995, p. 100.)
"I think we are moving past the point of a recommendation saying, 'We don't know what the best recommendation is, and therefore you are on your own,'" Fleming told Hospital Infection Control. "On balance, there is a strong argument that can be made for post-exposure [HCV] counseling and testing."
A litany of problems
Presented to HICPAC by Miriam J. Alter, PhD, chief epidemiologist in the CDC hepatitis branch, the CDC draft report cited numerous issues that made a recommendation for HCV follow-up problematic. Those include limited data on the risk of transmission, the limitations of available serologic testing for detecting infection and determining infectivity, the limited benefit of therapy for chronic disease, and medical/legal questions such as workers' compensation issues. With such limited options from a public health perspective to identify and treat infection, the CDC questioned whether it could prescribe policy. The agency concluded in the paper that "individual institutions may choose to develop their own policies and procedures to address individual workers' concerns about their risk and outcome and requirements for workmen's compensation claims."
Nonetheless, failure to make a more formal recommendation will translate to inaction at some hospitals, particularly those that decide the expense of follow-up is not merited by the low risk of occupational HCV infection, McCormick emphasized.
"I think we're copping out," she told the committee and CDC staffers present. Emphasizing that front-line health care workers want direction on HCV, McCormick said endorsing the CDC non-recommendation would be the equivalent of saying c'est la vie.
"I don't think that is what the document is saying -- I really don't," Alter answered.
Tracking infections presents challenge
There was some discussion about whether such a worker advocacy role was within the panel's charge, but there appeared to be consensus that addressing the issue was appropriate for the CDC's principal infection control advisory committee.
"Making guidelines that allow institutions to monitor the effectiveness of their own infection control programs is part of our responsibility," reminded committee member Susan W. Forlenza, MD, director of AIDS surveillance at the New York City Department of Health. "To me, it wouldn't be unreasonable to make a recommendation that [hospitals] do a follow-up and document [HCV] conversions that did occur in their institutions, because those are flags that something is not working."
A major problem with follow-up, however, is that testing methods readily available in the clinical setting have limitations, the CDC states. With the commercially manufactured enzyme immunoassays (EIAs) that detect anti-HCV, there may be a prolonged interval between exposure and seroconversion. In many populations, including health care workers, the rate of false positivity for anti-HCV is high, and supplemental assays should always be used to judge the validity of repeatedly reactive EIA results. About 10% of infections will be undetected unless polymerase chain reaction (PCR) is used to detect HCV RNA. Although PCR assays are available from several commercial laboratories on a research-use basis, they are not standardized, and the cost is high -- about $200 per test, the CDC draft states. Both false-positive and false-negative results can occur from improper handling and storage, or contamination of the test samples. In addition, the detection of HCV RNA may be intermittent, and the meaning of a single negative PCR test result is not conclusive. All anti-HCV positive persons should be considered potentially infectious, however, the CDC adds.
The most obvious benefit from a follow-up protocol would be the opportunity for the health care worker to seek evaluation for chronic liver disease and treatment if necessary, the CDC draft states. Studies have shown that alpha interferon therapy may have a beneficial effect among some patients, the agency noted.1 Even in those studies, however, therapy brought sustained improvement in 20% or fewer of those treated. No clinical, demographic, serum biochemical, serological, or histological features have been identified that reliably predict which patients will respond to treatment and sustain a long-term remission, the CDC noted.
"I think it is only going to get worse," Alter told the committee, saying current research suggests the response rate to initial treatment may be closer to 10%.
Universal precautions or special emphasis?
Given such a bleak epidemiologic picture with HCV, the CDC emphasized the importance of universal barrier precautions to prevent possible exposures to HCV and other bloodborne pathogens. That issue sparked some pointed HICPAC discussions about whether HCV warrants special emphasis, and whether such efforts undermine the universal precautions concept. In that regard, acting HICPAC Chairman C. Glen Mayhall, MD, professor of epidemiology at the University of Texas Medical Center in Galveston, questioned the wisdom of giving special emphasis to HCV rather than encouraging universal precautions with all bloodborne pathogens.
"We should just call it a day and go home -- that's what you're saying," replied Fleming. "I kind of feel like you're trying to rush this through."
Mayhall responded, "I'm not trying to rush it through. I just have a basic disagreement with you."
Interviewed after the meeting, Mayhall warned that achieving compliance with universal precautions is an ongoing struggle for ICPs and epidemiologists because health care workers may base infection control measures on their perceived risk from individual patients and bloodborne diseases.
"My concern with what was brought up in the committee is that once again we are focusing on a particular disease," he said. "Although I am quite comfortable about educating health care workers about the epidemiology of all these diseases, I have a feeling we may be focusing a little too much on a single disease."
On the other hand, Fleming argued that front-line health care workers may not realize the HCV risk, thus emphasizing the danger may actually improve compliance with routine infection control precautions.
"Daily in this country, health care workers are being exposed to blood and other secretions from patients that are HCV positive, and daily decisions are having to be made about what kind of post-exposure counseling and testing should be done," he told Hospital Infection Control. "I think that is an area where we need to provide as much guidance as possible."
The biggest mine in the field
As if the issue wasn't sufficiently complicated, the committee was reminded that attempting to develop more formal guidelines will invariably go beyond HICPAC to the highly controversial issue of the risk of HCV transmission to patients from infected providers.
"If we document anti-HCV positivity in health care workers, then we are going to be asked to address -- officially -- what to do with an HCV-infected health care worker," Alter told HICPAC. "That has not been addressed. . . . That is something that is going to have to be addressed in a more formal way."
Though the issue has not been addressed for HCV, CDC recommendations for HIV and hepatitis B virus call for health care workers who perform invasive procedures to know their HIV status and HBV e-antigen status.2 If infected, they should consult expert review panels regarding their continuing practice, the CDC advises. It may be particularly difficult to devise such a policy on HCV with current limitations in testing and difficulties in determining infectiousness on an individual basis.
"The risk that an HCV infected individual will transmit the virus may be related to the type and size of the inoculum and the route of transmission, as well as the titer of virus, but there are insufficient data on the threshold concentration of virus needed to transmit infection," the CDC draft paper states. "In the absence of such data and standardized tests to measure infectivity, it is difficult to counsel anti-HCV positive persons about their risk of transmission to others. Furthermore, there is the issue of whether such counseling should be provided after an exposure but prior to documented infection."
Though there may be insufficient data on HCV to justify recommending policy for infected health care workers, the issue became a reality after the CDC reported last year the first documented case of HCV provider-to-patient transmission in Spain. (See Hospital Infection Control, June 1995, pp. 74-76; August 1995, 99-101.)
Updating that case to HICPAC, Alter said five of six heart valve replacement patients in the identified cluster had the same HCV genotype as the HCV-positive surgeon considered the source of the infections. Though the exact route of transmission has not been determined, Alter said the surgeon had similar wound-closing practices as a surgeon in California who transmitted HBV to 18 patients. In the latter case, transmission is suspected to have occurred via microlesions on the surgeon's hands caused by prolonged suture tying. (See Hospital Infection Control, June 1993, pp. 73-77.)
"[The Spanish surgeon] also -- interestingly -- had the habit of closing his sternotomy wounds with his gloved hands, rather than with a sponge, which was similar to [the] surgeon who transmitted hepatitis B in California," she said. "Whether that was related, I don't know."
Surveillance may provide answers
Though the outbreak raises complicated questions for U.S. policy, some committee members pointed out the case at least showed more could be learned about the epidemiology of HCV via surveillance and investigation. Noting that, they drove home the point that a stronger recommendation for follow-up of occupationally exposed health care workers could prove beneficial.
"The epidemiologic investigation comes back and tells you a behavior that was common to another surgeon who had transmission of hepatitis B," Forlenza said. "We may learn something from that. . . . I see what you are recommending [for health care workers ], in a sense, as a head-in-the-sand approach."
References
1. Fried MW, Hoofnagle JH. Therapy of hepatitis C. Semin Liver Dis 1995; 15:82-91.
2. Centers for Disease Control and Prevention. Recommendations for preventing transmission of human immunodeficiency virus and hepatitis B virus to patients during exposure-prone invasive procedures. MMWR 1991; 40:1-9. *
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