CDC: Test workers for HBV immunity
As many as 10% may be non-responders
A growing number of health care workers are coming into their profession with childhood vaccination against hepatitis B virus (HBV). Yet 5% to 10% of them may unknowingly be non-responders to the vaccine, leaving them at risk if they have a bloodborne pathogen exposure, according to the Centers for Disease Control and Prevention.
The most protective strategy would involve serologic testing of these previously vaccinated employees at hire, the CDC says in newly released guidance.1 If they do not have antibody levels of at least 10 mIU/ml, they should receive a booster dose of the vaccine and retesting, CDC says. They may receive up to three new doses of HBV vaccine, the agency says.
Yet CDC also says employers may adopt a post-exposure approach, based on risk and cost factors. "The risk in certain occupations is an important consideration, as well as whether the person is a trainee or a non-trainee," says Trudy Murphy, MD, a medical epidemiologist and unit leader for CDC’s vaccine unit and a co-author of the guidance.
For example, some communities or hospital units may have a low prevalence of hepatitis B, and employees who are not involved in direct patient care would have a lower risk, she notes. Conversely, trainees have a higher rate of bloodborne pathogen exposures and therefore would be at higher risk, she says.
In a post-exposure program, health care workers would receive HBV serologic testing at the time of an exposure and would be revaccinated if they have antibody levels below 10 mIU/ml. If the source patient is hepatitis B surface antigen-positive or the HBsAg status is unknown, those exposed health care workers also would receive one dose of hepatitis B immune globulin.
A post-exposure approach hinges on prompt reporting and follow-up. Yet only about half (54%) of percutaneous and 17% of mucocutaneous exposures are reported, CDC notes.
"The only way to ensure protection is to take a pre-exposure approach or to have exposures reported and managed at the time of the exposure," says Murphy. "The goal here is to make sure that all health care workers or personnel are protected against hepatitis B."
Not related to OSHA regs
The CDC guidance does not affect the U.S. Occupational Safety and Health Administration requirement for employers to offer the hepatitis B vaccine to all employees who have a risk of exposure. Employees who decline the vaccine must sign a declination statement.
Only about 64% of health care workers reported having been vaccinated against hepatitis B in a 2011 survey.2 Vaccination rates are somewhat higher among health care workers in direct patient care, but they’re still well below the HealthyPeople 2020 goal of 90%.3
Some other issues to consider related to HBV vaccination of health care workers:
• CDC recommends pre-vaccination serologic testing of health care workers who may have a higher risk of being infected with hepatitis B, including HCWs born in geographic regions where HBV is endemic (eastern Europe, Asia, Africa, the Middle East and Pacific Islands) or people who were not vaccinated as infants and whose parents were born in those regions; HCWs who received the HBV vaccine as adults or adolescents, after they began engaging in high-risk behaviors; people who are HIV-positive or who receive hemodialysis. They should be tested for HBV surface antigens as well as HBV antibodies, CDC says.
• Health care workers who have written documentation of a completed three-dose vaccination series and subsequent serologic testing that showed an immune response do not need further testing — even years later. "We think the vaccine protection is holding up very well after 20 years," Murphy says.
• HCWs with documented immunity to HBV do not need post-exposure management, even if the source patient is HBV-positive.
• Hospitals should consider using an electronic system for maintaining HCW immunization records. That makes it easier for hospitals to access the records if there is an exposure and to provide the records for HCWs who move to a new facility, says Murphy.
•About 800,000 to 1.4 million Americans have chronic HBV, so the risk of exposure remains significant, she says. "They’re asymptomatic for the most part, so the health care personnel would not automatically recognize they have hepatitis B," she says.
CDC received reports of 203 cases of acute HBV among health care workers from 2005 to 2010. Although information about occupational exposures was limited, 28, of 17% of cases with available information, had sustained a sharps injury. In about half the cases, HCWs had other risk factors for HBV.
"People who are at risk do get infected and they can become chronically infected," says Murphy.
- Schillie S, Murphy TV, Sawyer M, et al. Centers for Disease Control and Prevention. CDC guidance for evaluating health-care personnel for hepatitis B virus protection and for administering post-exposure management. MMWR 2013; 62(RR10): 1-19.
- Centers for Disease Control and Prevention. Non-influenza vaccination coverage among adults United States, 2011. MMWR 2013; 62:66-72.
- Byrd KK, Lu PJ, and Murphy TV. Hepatitis B vaccination coverage among health-care personnel in the United States. Public Health Reports 2013; 128:498-509.