Hospital savings aren’t chicken feed for vaccinating workers for varicella
Some hospitals make chickenpox vaccination a condition of employment
All health care workers in hospitals should be vaccinated for varicella (chickenpox) to control possible outbreaks and avoid costly furloughs of exposed employees, experts say. The financial savings that can be achieved through a universal vaccination program can run as high as $50,000 in the first year alone. (See related story, p. 110.)
Recently, the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention in Atlanta updated its varicella vaccination recommendations, calling for greater use of the vaccine to limit the extent of outbreaks. The CDC reinforces its admonition for postexposure vaccination and outbreak control at hospitals and other health care facilities, according to Jane Seward, MD, chief of varicella activity for the National Immunization Program at the CDC. A small proportion of adults — those who didn’t get varicella as children and haven’t been vaccinated — are not immune to the disease.
"The original recommendation stated that all hospital workers get the varicella vaccine, and we repeat that in the new recommendation," says Seward. She adds that serum titers for employees who are not certain of their varicella history, followed by a concerted effort to vaccinate varicella-susceptible employees, is a far more cost-effective strategy than furloughing at-risk workers for 10 to 21 days following an exposure.
Hospitals appear to have taken the CDC recommendations seriously. However, strategies at individual institutions to control varicella exposures and limit outbreaks among patients and health care workers differ markedly.
At the Santa Clara Valley Medical Center, a 600-bed teaching facility affiliated with Stanford University Medical School in San Jose, CA, Employee Health Services (EHS) tests all hospital employees for varicella antibodies before they begin their jobs, says Donna J. Haiduven, BSN, MSN, CIC, PhD-C, infection control supervisor. Varicella-susceptible employees are encouraged to receive the vaccination series of two injections, but compliance is not mandatory.
Employees with negative antibody titers are required to notify the Infection Control Depart ment in the event of a varicella exposure, whether it occurs at the hospital or elsewhere. While many institutions might send these individuals home, Santa Clara allows exposed, non-immune employees to continue working as long as they wear masks for 10 to 21 days after the exposure and screen themselves daily for symptoms of varicella. If symptoms appear, the Infection Control Depart ment sends them home until all lesions are dried and crusted.
For those who question the wisdom of allowing varicella-susceptible employees to continue working after an exposure, Haiduven offers some impressive statistics: During the 12 years since the policy took effect (eight years before the varicella vaccine became available), more than 200 exposures to varicella have been reported at the hospital. Among these, approximately 200 health care workers have been required to wear a mask after exposure, yet no more than six employees came down with varicella, and no secondary cases were reported.
Haiduven speculates that her institution’s conservative definition of what constitutes an exposure may partially explain why Santa Clara has had so few cases of varicella among non-immune employees.
"There is no standard definition of a varicella exposure in the literature," Haiduven explains. "When an exposure to varicella occurs, it’s very hard to determine how long that exposure lasted. Some people will say an exposure has occurred after face-to-face contact with a patient in a room for an hour; some will say five minutes. Our definition of an exposure is when a health care worker has any direct or face-to-face contact with a person with chickenpox for any length of time. Hospitals really need to have a definition of what they consider to be an exposure in their varicella policies. Our approach gets to the root of the problem, and we believe a mask is protection enough."
Haiduven also conservatively calculates the beginning of the potential exposure period by counting back three full days from the time a rash develops, effectively adding three days to the typical 10- to 21-day period during which a person with varicella is considered contagious.
If an employee develops a rash during the period from the first dose of the vaccine to a month after the second dose, the health care worker is required to report to EHS for an evaluation. If the rash appears only at the injection site, the employee will probably be allowed to continue working. If the rash becomes more widespread, he or she goes home.
Enacting consistent and conservative’ policy
Haiduven’s caution arose in large part because the vaccine is effective in 70% to 90% of cases (though it protects against the development of serious disease 95% of the time).
"We have to consider the 10% to 30% who are not protected, so we treat all employees who have been vaccinated as if they are susceptible to varicella. The policy is consistent and conservative," Haiduven says. "We need to protect our patients, other employees, and visitors from those who may be vaccinated but not immune."
Santa Clara doesn’t require post-vaccination serology to confirm seroconversion, though the test is occasionally used for research purposes. The reason, Haiduven explains, is based on the statement in the ACIP Guidelines for Varicella Prevention that "seroconversion does not always result in full protection against disease."
The vaccination policy is far sterner at the University of North Carolina Hospital in Chapel Hill, a 650-bed tertiary care facility that employs approximately 4,500 health care workers. Varicella vaccinations are mandatory, even though the word "mandatory" is not mentioned in the CDC’s recommendations, according to David Jay Weber, MD, MPH, medical director, hospital epidemiology and occupational health.
"If you want to work at our hospital or any other University of North Carolina hospital, you must be vaccinated for mumps, measles, rubella, and varicella, unless you have a medical contraindication to receiving a vaccination. That goes for medical and nonmedical staff, students, volunteers, and contract workers who work in clinical areas," explains Weber. The policy went into effect about six months after the varicella vaccine became available in 1995.
"This is a win-win-win situation," Weber adds. "It’s good health for the public, it’s good for employees, and it’s good for patients. If you look at any standard immunization guideline, it will tell you there is no age at which childhood immunization should not be provided. Now that varicella vaccine is a universal vaccine, the American Academy of Pediatrics, the American College of Physicians, and other organizations would argue that everybody should be immunized. This is just part of good health care."
Hospital employees are at high risk for exposure to and contracting varicella, and solid, peer-reviewed research shows that more than 1.5% of adults with varicella require hospitalization, Weber continues. An outbreak can cost tens of thousands of dollars.
"We believe we’re protecting our employees, and published studies suggest a cost benefit from providing the vaccine over sending infected employees home," he says.
Well before the vaccine went on the market, one-third to one-half of the hospital’s varicella-susceptible employees signed up to be vaccinated. Many did so because they didn’t want to bring varicella home to their children, according to Weber. "This is not a hard sell," he adds. "Many of our employees were appreciative that we did this."
That’s not to say there isn’t an occasional employee who dislikes the fact that vaccination is mandatory. But the overwhelming majority of hospital employees has expressed positive opinions about the program, Weber reports.
"The libertarian argument that vaccinations should not be mandatory doesn’t hold at this institution. Our view is that as a condition of employment, there are lots of things we tell people: They have to wear gloves when they touch blood; they have to wear hard hats in construction areas. This is a condition of employment. People are free to not work at our hospital if they don’t want to," says Weber.
Since the mandatory vaccination program went into effect, Weber says no staff members have developed varicella from workplace exposures. The number of exposure evaluations are "way down," as are the costs of managing the disease. "I don’t know if we’ve had any full-blown breakthrough cases or home exposures," he says, adding that 2% to 4% of vaccinations result in a generalized rash, but such breakthrough disease is far milder than a typical case of varicella.
An employee who states definitively that he or she had varicella is enough evidence for Weber. Those who are uncertain undergo serology. About two-thirds of those tested do not have anti-varicella antibodies and require vaccination. The direct cost of the serology is $12, which doesn’t take into consideration labor costs and indirect expenses.
"We were spending $50,000 a year on chickenpox control, and I think our whole vaccine campaign was on the order of about $15,000. I’m sure that we’re still saving more than the cost of our entire vaccine campaign costs each year," Weber says.
Vaccinations encouraged, but not mandated
At Washington Hospital Center in Washington, DC, all employees undergo routine screening for varicella resistance during a preplacement physical examination. The Occupational Health Department takes the word of an employee who says he or she already had varicella. Individuals with negative varicella titers are counseled to get vaccinated, but vaccinations are not mandatory. Susceptible employees are instructed to avoid rooms housing patients with varicella or herpes zoster, and they must report any suspected exposure to their supervisors and to the Occupational Health Department, regardless of where the exposure occurred.
If an employee receives the vaccination and develops a rash at the injection site, the rash is covered and the worker is removed from patient care duty until the rash resolves, usually in two to three days. Employees who develop a generalized rash are removed from duty until the rash resolves.
"There is no need to remove or test other employees who have contact with a colleague who develops a vaccine-related rash, because the likelihood of transmission is very low," says Ann Marie Gordon, MD/MPH, director of occupational health at Washington Hospital Center.
When a patient is known to have varicella, the Infection Control Department is notified, which in turn provides the Occupational Health Department with a list of all employees who had contact with that patient and all employees who were exposed 48 hours prior to the onset of the patient’s symptoms.
Exposed employees tested for antibodies
"We will identify employees from all departments who may have been exposed to the patient," says Gordon. "Once we have that list, we can determine which employees might be susceptible to varicella and require them to receive varicella titers."
Negative titers result in removal from duty. But if varicella antibodies are present, no restrictions are placed on the worker. Antibody testing is repeated five days after an exposure. "We also will notify the appropriate department heads of susceptible employees, who are considered communicable from the 10th to the 21st day from exposure. They are not to work during this period," Gordon adds.
Susceptible employees who choose not to be vaccinated must sign a declination form. Should they become exposed to varicella or herpes zoster on or off the job, they are sent home and must use any available vacation time or sick days to cover their absence. An employee who develops varicella must immediately contact his or her department head and the Occupational Health Department, which confirms the diagnosis and compiles a list of employees and patients who were exposed to the individual. The sick employee is not allowed to return to work until cleared by Occupational Health, and any susceptible employees on the contact list are removed from duty, as in any postexposure situation, says Gordon.
At Dartmouth-Hitchcock Medical Center in Lebanon, NH, immunized workers who are exposed to varicella virus are told to report to Occupational/Employee Health for evaluation and a review of work responsibilities. If they remain asymptomatic, they may continue to work but should not care for immunocompromised patients who are susceptible to varicella for 10 to 21 days postexposure. Employees who develop skin lesions should discontinue patient care and are evaluated by Occupational/Employee Health.
An employee who received both doses of varicella vaccine may decide if he or she will provide direct care to patients who have been isolated for varicella, varicella exposure, or herpes zoster. Unvaccinated employees who develop varicella are furloughed until their lesions are dry and crusted and they have been cleared by Occupational/ Employee Health to return to work.
According to Carolyn Murray, MD, MPH, in the Section of Occupational Medicine, the hospital’s varicella guidelines are undergoing minor revisions in light of the recent CDC update. (See varicella vaccine consent form, inserted in this issue.)
Vaccination is optional but strongly recommended at St. Joseph Hospital in Chicago, according to Caroline Guenette, MS, RNC, occupational health nurse practitioner and manager of Employee Health Services. When the vaccine was first offered at the hospital in 1996, Guenette’s department searched for employees with negative or borderline immunity as determined by serology. The quest identified about 60 potentially susceptible workers out of an employee population of 1,800. More than half opted to receive the vaccine. Post-vaccination titers are not conducted because the serology test typically used by health care institutions is somewhat unreliable, and vaccine experts state that 99% of recipients will be seropositive following the second dose of the vaccine (though a recent study sheds some doubt on that assertion; see story, p. 110). Volunteers are not vaccinated.
The hospital’s original varicella policy stated that unvaccinated employees exposed to varicella had to leave work for the duration of the contagious period. That policy changed briefly.
"Someone at one of our other hospitals [in the Catholic Health Partners system] suggested removing exposed employees from patient care duties instead of putting them on furlough," recalls Guenette. "But in our first attempt to do that, the employee got varicella. After that, the infection control physician insisted we go back to the furlough program." Furloughed employees are paid through workers’ compensation and are not required to use vacation or sick days.
As at other facilities, a list of all employees who had contact with a susceptible, exposed employee is compiled to identify at-risk employees, who are also furloughed.
Vaccinations are not mandatory, explains Guenette, because it is not part of the recommendations of the Chicago Board of Health, the CDC, or the Occupational Safety and Health Administration. Guenette estimates that two varicella exposures occur each year, and only two or three individuals have been furloughed since the vaccine came out. Only one employee who was vaccinated during employment developed a mild rash, but there have been no breakthrough cases of varicella.
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