Survey reveals controversy concerning titer testing
August 1, 1999 8 minutes read
Survey reveals controversy concerning titer testing
Hepatitis B vaccination policies vary
The issue of postvaccination titers — when to test, why, and what to do if they’re low or negative — emerges as the most controversial aspect of hepatitis B vaccination programs for health care workers, according to the exclusive Hospital Employee Health survey of readers’ policies and procedures.
A fax-back survey included in the June 1999 newsletter drew 135 responses from employee health professionals who work across the country in facilities with between 140 and 12,000 workers. (See chart, at right.) Respondents answered 12 questions ranging from the number of employees considered eligible for HBV vaccination to whether they test for prevaccination and postvaccination titers and why. Other questions asked about policies regarding low postvaccination titers, who pays for titer tests and revaccinations, and whether the vaccine produced any adverse reactions.
Of the total number of employees — 148,249 — employed at the hospitals of respondents who provided complete sets of figures, 79% were considered eligible to be offered HBV vaccine. While the Occupational Safety and Health Administra tion (OSHA) requires health care facilities to offer vaccine to workers with the potential for blood and body fluid exposures,1 nearly one in four facilities responding to the survey (24%) offer vaccine to all employees.
"We push HBV vaccine for all direct caregivers and ancillary staff, such as housekeeping and laundry," says Nancy B. Childs, RN, BSN, CIC, director of infection control and employee health at 1,000-employee Holzer Medical Center in Gallipolis, OH. "We offer it to every employee."
At Johnston Memorial Hospital in Abingdon, VA, industrial/employee health nurse Darla Barrow, RN, also classifies all employees as eligible for HBV vaccine. She presently has vaccinated 98.3% of the facility’s 654 employees with all three doses. Only two workers signed declinations, and nine presented physicians’ letters stating the vaccine was contraindicated due to allergies and other health conditions.
Barrow has a two-pronged strategy for obtaining compliance. First, she speaks to new employees at orientation, after which she offers vaccine on the spot. Second, she follows up with a personal work site visit.
"After three months, if we have some who have not taken it, I go talk to them individually and see what their reasons are," she says. "I explain to them the importance of being vaccinated. If they say they don’t like needles, I tell them, This is three [injections] over a six-month period when you get the vaccine, but can you imagine how many times you’re going to be stuck if you get hepatitis?’"
Overall, the survey shows that an average of 80% of employees classified as eligible have completed the three-vaccine series. Eleven percent of those eligible declined to be vaccinated. (See chart, p. 90, top.)
Asked if they test for prevaccination titers, most respondents (84%) answered that they do not. For the 16% who indicated that they do prevaccination testing, the main reasons were if employees began the series at another facility or in school, if they never had a titer drawn, as part of the preplacement physical assessment, or to establish a preplacement baseline for liability purposes.
Several respondents said they test before vaccinating based on occupational risks or on history of hepatitis or birthplace. Steven R. Weiner, FNP, MS, MPA, clinical manager of employee health at New York University Medical Center, says testing for prevaccination titers at the 8,348-employee facility has "demonstrated cost-effectiveness" due to high HBV seroprevalence in New York City, with its "international population."
Other reasons given for testing included: only for renal dialysis staff, if employees have no medical records, to rule out active HBV, or upon employee request.
Cost-effectiveness is the only rationale for prevaccination titering, says William Bower, MD, a senior research associate with the hepatitis branch of the federal Centers for Disease Control and Prevention (CDC). Otherwise, the practice is not recommended.
Answers to questions related to testing for postvaccination titers and the need for booster doses generated the biggest differences and the most comments in the survey results.
The CDC now recommends postvaccination titering one to two months after completion of the three-vaccine series for HCWs who have contact with patients or blood and are at risk for sharps injuries. Workers who do not respond to the primary vaccine series should complete a second three-dose series or be evaluated to determine if they are HBsAg-positive. Revaccinated workers should be retested following completion of the second vaccine series. Primary nonresponders who are HBsAg-negative should be counseled about the need for hepatitis B immune globulin (HBIG) after high-risk exposures.2 (For more information about postexposure treatment, see chart, below.)
Most (94%) survey respondents indicated that they test for postvaccination titers. Of those, 85% said they test within six months, with most indicating they test between four and eight weeks postvaccination completion. Three percent said they test after five years, 1% after 10 years, and 48% after a needlestick injury/occupational exposure. Four percent said they test postvaccination titers at other times, such as every year, one year later, six years later, or at an employee’s request. (See chart, p. 91, top.)
If postvaccination testing reveals a low titer, 50% of respondents said their policy is to administer one booster dose and retest. Thirty-four percent reported they repeat the entire three-vaccine series and retest. Fourteen percent said they give HBIG after a high-risk needlestick, and 17% gave a variety of answers in the "other" category. Those answers included: repeating the vaccine series but not retesting; giving a booster dose but not retesting; giving two boosters and retesting; giving up to three boosters and retesting after each; giving a booster, retesting, giving two more boosters if titers remain low, then retesting; and giving up to six booster doses. (See chart, above.)
Bower says the chance of developing adequate titers is 95% following the three-vaccine series. CDC guidelines note that while vaccine-induced antibodies decline gradually over time, vaccine-induced immunity continues to prevent clinical disease or detectable viremic HBV infection. An anamnestic immune response after HBV exposure is the proposed mechanism for continued protection against HBV infection despite antibody titers that have declined below detectable levels. Therefore, the CDC considers booster doses unnecessary for HCWs who have responded to vaccination and have a normal immune status; nor does the agency recommend testing titers except for one to two months postvaccination.2,3
The bloodborne pathogens standard states only that hospitals are to follow current CDC recommendations for postvaccination titer testing, but an OSHA spokesman says a new compliance directive being finalized will specify that titers are to be tested only one to two months after completion of the vaccine series.
Nevertheless, some employee health professionals responding to the survey take a more cautious view.
The infection control committee at Olean (NY) General Hospital decided to test hepatitis B surface antibody for all vaccinated employees after needlestick follow-ups indicated that three out of four exposed workers were nonimmune, says Cindy Rodd, RN, employee health manager. They discovered that overall, 40% of employees were not immune to HBV.
"We boosted them, took another titer, and if they were still nonimmune, we gave another booster, then another titer. If they were still not immune at that point, we stopped there," she explains. "We gave them special instructions to double-glove and to report needlesticks immediately."
Between six and eight of the facility’s 900 employees still lack immunity after five injections, she says.
Vaccinated employees are tested for immunity at preplacement, and postvaccination titers are tested six to eight weeks after completion of the vaccine series.
"We don’t mind the cost because we want people to know if they’re immune or not," Rodd states. "The anamnestic response is one school of thought, but our infection control committee still wants to go ahead with our policy."
Vaccinated workers at 1,600-employee Trinity Health System in Steubenville, OH, are offered the option of having their titers checked six years after the third or last vaccine they’ve received, says employee health coordinator Karen Russell, RN, BSN, COHN-S. The practice was begun six years ago.
"At first, we didn’t know how long the antibody titer would be good for. Since that time, there’s been some other information published by the vaccine manufacturer, stating [that titers remain positive] 10 to 12 years, but we wanted to see if employees still had titers six years after the vaccine," she relates.
Results of the titer testing showed that nearly one out of three employees tested six to eight years postvaccination had negative antibodies. Between 85% and 89% of vaccinated workers now take advantage of the titer-testing opportunity, notes Russell, who adds that she still sees "quite a few" negative titer reports, but not as many as at first. Employees with negative titers six years postvaccination are offered a booster dose.
"Research [into postvaccination immunity] is still going on," she says. "That’s what makes it so hazy."
Annette Cort, RN, employee health coordinator at The Cornwall (NY) Hospital, says the policy at her 560-employee facility is to test all workers every year for postvaccination titers. She finds workers are remaining positive for five to seven years postvaccination, with 10% to 15% showing negative titers after that.
"We want to make sure they’re staying positive," she states. "If not, we give them a booster."
Adverse reactions noted
Ninety-nine percent of survey respondents indicated that the employer pays for titer tests and revaccinations. One respondent said her employer pays for vaccine, but employees pick up the tab for titer testing.
Responses to the survey question asking whether employees have had or claimed to have had an adverse reaction to HBV vaccine were split down the middle. Fifty percent answered yes, with the most common reactions listed being rash, itching, local reactions at the injection site, upper arm soreness and swelling, arthralgia, fever, nausea/vomiting/diarrhea, malaise/fatigue, allergic reactions, and flu-like symptoms.
Other adverse reactions noted include anaphylaxis/shock (two employees), elevated liver enzymes, hives, hair loss, visual disturbance/eye pain, chest pain, headache, abdominal pain, welts, and Guillain-Barré syndrome.
The most common side effects from hepatitis B vaccination are pain at the injection site and mild to moderate fever, Bower notes. He adds that carefully controlled studies are under way to examine whether vaccination is associated with serious neurological disease in a small number of people.
However, presently there is no confirmed scientific evidence that hepatitis B vaccine causes chronic illnesses, including multiple sclerosis, chronic fatigue syndrome, rheumatoid arthritis, optic neuritis, or other autoimmune disorders.
"Serious adverse events reported after receiving hepatitis B vaccine are very uncommon and may represent coincidence rather than causation," he says. "Given the frequency and severity of hepatitis B infection, the benefit of vaccination far outweighs the known and potential risks."
References
1. U.S. Department of Labor, Occupational Safety and Health Administration. Occupational exposure to bloodborne pathogens: Final rule. 56 Fed Reg 64,004-64,182 (Dec. 6, 1991).
2. Centers for Disease Control and Prevention. Immunization of health-care workers: Recommendations of the Advisory Committee on Immunization Practices (ACIP) and the Hospital Infection Control Practices Advisory Committee (HICPAC). MMWR 1997; 46(No. RR-18):1-42.
3. Mahoney FJ, Stewart K, Hu H, et al. Progress toward the elimination of hepatitis B virus transmission among health care workers in the United States. Arch Intern Med 1997; 157:2,601-2,605.
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