CDC may call for HCV screening in hemodialysis

But not likely to recommend patient isolation

The Centers for Disease Control an Prevention will soon issue new infection control guidelines for hepatitis C virus in hemodialysis settings that may recommend routine HCV testing of patients to better identify outbreaks and reinforce infection control measures, Hospital Infection Control has learned.

"At the current time, we are re-drawing up our recommendations for hepatitis C screening," says Suzanne Cotter, MD, medical epidemiologist in the CDC hepatitis branch. "We previously have not recommended routine screening. We didn’t discourage it, but we have not specifically [recommended] that they should be doing it. Now it is possible, and probably likely, that that recommendation may be changed in the future. There will be a new document coming out [this] year about infection control practices in hemodialysis centers."

Developed by the hepatitis branch and the CDC hospital infections program with the consultation of experts in working groups, the new guidance is expected to be issued in the coming months for all facilities that conduct hemodialysis, she says. "Some of the centers are hospital-affiliated and some are freestanding, but our recommendations apply to all," she says. The current CDC guidelines state that "periodic [HCV] testing of long-term hemodialysis patients for purposes of infection control is currently not recommended."1 However, the CDC recommends that all hemodialysis patients be monitored monthly for signs of elevated liver enzymes to spot signs of HCV infection and other forms of hepatitis.

HCV testing could identify clusters, guide medical interventions, and reinforce infection control measures. However, it is not currently thought that the CDC will go as far as recommending the kind of stringent isolation and cohorting measures used for hemodialysis patients chronically infected with highly transmissible hepatitis B virus. "Appropriate use of hemodialysis-center precautions should prevent transmission of HCV among chronic hemodialysis patients, and isolation of HCV-positive patients is not necessary or recommended," the current CDC guidelines state.

"We’re not saying that hepatitis C patients need to be isolated, because all the studies that have been done have indicated that with good infection control practices, transmission does not occur," Cotter says.

Indeed, numerous infection control breaches were identified in an HCV outbreak at a hemodialysis center investigated by Cotter and colleagues.2 Poor infection control practices led to transmission of HCV to seven patients who used dialysis stations after patients with chronic HCV, Cotter explains. Blood contamination of equipment and supplies was the most likely route of transmission, she notes. "Transmission in this hemodialysis center was related to following a chronically infected patient," she says. "[We also] identified that the [hemodialysis] station was contaminated. We don’t know exactly how, but there was a lot of opportunity for contamination that we identified. When they improved their infection control practices — they did not isolate hepatitis C patients, but they simply improved their practices — transmission ceased. That is an important message, and there have been no further cases."

Of 51 patients tested at the center, 11 were previously known to be HCV-positive. Of the remaining 40, seven (17.5%) had seroconverted to HCV. All the seroconversions occurred on the second and third shifts. During those times, case patients followed chronically infected patients on the same dialysis machine more frequently than control subjects. "So we know that they were at risk because they followed [HCV-positive patients]," she says. Moreover, numerous instances of blood contamination of environmental surfaces were identified, suggesting there were several avenues by which transmission could have occurred. For example, there were indications that staff were not regularly cleaning out and changing "priming buckets," which are used as part of the process of flushing the lines out in the hemodialysis machine.

"There is potential for that fluid to have been contaminated from the patient’s blood," Cotter says. "When the next patient comes on, if that has not been emptied, it’s possible that what’s in that bucket can contaminate the tubing [used on] the next patient. All materials that are used for patient care should be either disposed or cleaned and disinfected prior to the next patient using them."

In addition, investigators found that a multidose vial of heparin solution may been used among patients, suggesting another route for HCV transmission. Enforcing existing hemodialysis recommendations — including prohibiting shared medications and equipment and proper cleansing and disinfection of the environment — halted the outbreak. (See recommendations, above.) The CDC also recommended that the patients have specific dialysis stations assigned to them and patients be screened for HCV every three months. However, that screening recommendation was in response to an outbreak situation and will not necessarily be the policy recommended in the updated CDC guidance, Cotter notes.

References

1. Centers for Disease Control and Prevention. Recom mendations for prevention and control of hepatitis C virus (HCV) infection and HCV-related chronic disease. MMWR 1998; 47 (No. RR-19):1-39.

2. Cotter S, Akinbami L, Sipe K, et al. Transmission of hepatitis C virus in a chronic hemodialysis center. Abstract 460. Presented at the Infectious Disease Society of America Conference. Philadelphia: Nov. 18-21, 1999.