MMWR Update

CDC stresses HCV risk in hemodialysis centers

No restrictions recommended for HCV+ providers

Nosocomial transmission of hepatitis c virus (HCV) may occur in hemodialysis centers if infection control techniques or disinfection procedures are inadequate and contaminated equipment is shared among patients, the Centers for Disease Control and Prevention emphasizes as part of an overall update of HCV guidelines.¹

Although reports from other countries document nosocomial HCV transmission in other settings, such transmission has rarely been reported in the United States other than in chronic hemo di alysis settings, the CDC reports. Prevalence of antibody to HCV (anti-HCV) positivity among chronic hemodialysis patients averages 10%, with some centers reporting rates of more than 60%. Both incidence and prevalence studies have documented an association between anti-HCV positivity and increasing years on dialysis, independent of blood transfusion. Those studies, as well as investigations of dialysis-associated outbreaks of hepatitis C, indicate that HCV transmission might occur among patients in a hemodialysis center because of incorrect implementation of infection-control practices, particularly sharing of medication vials and supplies.^2-8

"In chronic hemodialysis settings, intensive efforts must be made to educate new staff and reeducate existing staff regarding hemodialysis-specific infection control practices that prevent transmission of HCV and other bloodborne pathogens," the CDC emphasizes. "Hemodialysis-center precautions are more stringent than standard infection control precautions." (See box, at right.)

Standard precautions require use of gloves only when touching blood, body fluids, secretions, excretions, or contaminated items. In contrast, hemodialysis-center precautions require glove use whenever patients or hemodialysis equipment is touched. Standard precautions do not restrict use of supplies, instruments, and medications to a single patient. In contrast, hemodialysis-center precautions specify that none of those items be shared among any patients.

"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 CDC stated.

In other health care settings, workers should be educated regarding risk for and prevention of bloodborne infections. Standard barrier precautions and engineering controls should be implemented to prevent exposure to blood. Protocols should be in place for reporting and follow-up of percutaneous or permucosal exposures to blood or body fluids that contain blood. Health care professionals who oversee patients who receive home infusion therapy should ensure that patients and their families or caregivers are informed of potential risk for infection with bloodborne pathogens, and should assess their ability to use adequate infection-control practices consistently. Patients and families should receive training with a standardized curriculum that includes appropriate infection-control procedures, and these procedures should be evaluated regularly through home visits.

"Currently, no recommendations exist to restrict professional activities of health care workers with HCV infection," the CDC guidelines state. "As recommended for all health care workers, those who are HCV-positive should follow strict aseptic technique and standard precautions, including appropriate use of hand washing, protective barriers, and care in the use and disposal of needles and other sharp instruments."

The risk for HCV transmission from an infected health care worker to patients appears to be very low. One published report exists of such transmission during performance of exposure-prone invasive procedures.⁹ That report, from Spain, described HCV transmission from a cardiothoracic surgeon to five patients, but did not identify factors that might have contributed to transmission. Although factors (e.g., virus titer) might be related to transmission of HCV, no methods currently exist that can reliably determine infectivity, nor do data exist to determine threshold concentration of virus required for transmission, the CDC concludes.

Individual institutions should establish policies and procedures for HCV testing of persons after percutaneous or permucosal exposures to blood and ensure that all personnel are familiar with these policies and procedures. Health care professionals who provide care to people exposed to HCV in the occupational setting should be knowledgeable regarding the risk for HCV infection and appropriate counseling, testing, and medical follow-up.

Immune globulin and antiviral agents are not recommended for postexposure prophylaxis of HCV. Limited data indicate that antiviral therapy might be beneficial when started early in the course of HCV infection, but no guidelines exist for administration of therapy during the acute phase of infection. When HCV infection is identified early, the individual should be referred for medical management to a specialist knowledgeable in this area, the CDC advises.

References

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

2. Allander T, Gruber A, Naghavi M, et al. Frequent patient-to-patient transmission of hepatitis C virus in a hematology ward. Lancet 1995; 345:603-607.

3. Bronowicki JP, Venard V, Botte C, et al. Patient-to-patient transmission of hepatitis C virus during colonoscopy. N Engl J Med 1997; 337:237-240.

4. Schvarcz R, Johansson B, Nyström B, Sönnerborg A. Nosocomial transmission of hepatitis C virus. Infection 1997; 25:74-77.

5. Guyer B, Bradley DW, Bryan JA, Maynard JE. Non-A, non-B hepatitis among participants in a plasmapheresis stimulation program. J Infect Dis 1979; 139:634-640.

6. Moyer LA, Alter MJ. Hepatitis C virus in the hemodialysis setting: A review with recommendations for control. Seminars in Dialysis 1994; 7:124-127.

7. Niu MT, Coleman PJ, Alter MJ. Multicenter study of hepatitis C virus infection in chronic hemodialysis patients and hemodialysis center staff members. Am J Kidney Dis 1993; 22:568-573.

8. Niu MT, Alter MJ, Kristensen C, Margolis HS. Outbreak of hemodialysis-associated non-A, non-B hepatitis and correlation with antibody to hepatitis C virus. Am J Kidney Dis 1992; 4:345-352.

9. Esteban JI, Gomez J, Martell M, et al. Transmission of hepatitis C virus by a cardiac surgeon. N Engl J Med 1996; 334:555-560.