Improving hepatitis B vaccination rates in the hemodialysis population.

More than 2 billion people worldwide are estimated to have been infected with hepatitis B virus (HBV), and of these, 360 million are chronic carriers of HBV (Table 1).1 HBV is transmitted through exposure to infected blood or body fluids, and untreated exposure has a 30% risk of seroconversion.2 If primary infection occurs, about 95% of immunocompetent adults will experience a self-limiting disease and subsequently become immune to future infection. However, patients infected with human immunodeficiency virus (HIV) or who receive hemodialysis are at a higher risk of contracting HBV infection and becoming chronic carriers of HBV.2,3 People who develop chronic HBV infection are at risk for hepatocellular carcinoma, cirrhosis of the liver, and death, as well as serve as a means for transmitting infection to other unvaccinated or undervaccinated individuals.3 The most efficient and effective manner by which to prevent HBV infection is vaccination. The Centers for Disease Control and Prevention (CDC) and its Advisory Committee on Immunization Practices (ACIP) have identified high-risk populations for which vaccination is recommended: intravenous drug users, individuals engaging in high-risk sexual behavior, patients in long-term care facilities, and patients with chronic liver disease, with HIV infection, or who receive hemodialysis. In addition, health care workers are at high-risk of contracting HBV through occupational exposure and, according to CDC recommendations, should receive vaccination against HBV.3 The risk of HBV exposure with peritoneal dialysis has declined considerably because peritoneal dialysis has been moved to home therapy. The prevalence of exposure in these patients is now about the same as in the general population. Currently, the risk of HBV infection in patients receiving peritoneal dialysis is directly related to historical time spent on hemodialysis and exposure to blood products.2 Hemodialysis patients are at extremely high risk of contracting HBV infection because of their inherent immunocompromised state, frequent use of the health care system, and numerous procedural and surgical interventions. The process of hemodialysis itself directly exposes patients’ blood to potentially contaminated equipment, as HBV can survive for up to 7 days on surfaces.3 In 1977, CDC published guidelines for the prevention of viral transmission in hemodialysis patients. The guidelines recommended serologic surveillance of patients for HBV, restriction of HBVinfected patients to designated dialysis equipment, and specific cleaning and sterilization techniques. After implementing these guidelines, the incidence of new HBV infections decreased from 6.5% in 1974, to 1% in 1980, and to 0.05% in 1997.4,5 Although these infection control practices substantially reduced the incidence of HBV, outbreaks within hemodialysis centers continue to be reported.6 In the current era, hemodialysis patients are at greatest risk of contracting HBV infection if they frequent a dialysis center that has a HBV vaccination rate of less than 50% or at least one HBV-infected patient not using designated equipment.7 Updated guidelines published in 2001 continue to support infection control, safe handling of sharps, avoidance of multidose vials, and vaccination.7 However, the persistent outbreaks of HBV in hemodialysis centers has been attributed to noncompliance with guideline recommendations for isolation, infection control, and vaccination.2