HICPAC OKs pertussis vaccination for HCWs

Discussions center around long-term care, costs

After some pointed discussion and one dissenting vote, the Centers for Disease Control and Prevention's Healthcare Infection Control Practices Advisory Committee (HICPAC) recently endorsed recommendations to immunize health care workers with the new pertussis vaccine.

The action came at a June 1 HICPAC meeting in which the committee approved the recommendations previously put forth by the CDC's Advisory Committee on Immunization Practices (ACIP). The recommendations — which now will be issued as jointly endorsed by ACIP and HICPAC — are designed to protect health care workers and their patients, particularly neonates who would not be indicated for pertussis vaccination but may be vulnerable to complications after infection.

The vaccine approved last year is a tetanus toxoid, reduced diphtheria toxoid (Td) and acellular pertussis vaccine (Tdap), which is designed as a single dose booster vaccine for people 11-64 years of age. It provides protection against tetanus, diphtheria, and pertussis. Although most children are protected against pertussis by vaccination during childhood, immunity wanes over time and leaves adults unprotected. In 2004, U.S. adults 19-64 years of age accounted for 7,008 of 25,827 (27%) reported pertussis cases. The true number of cases among adults 19-64 years is likely much higher, estimated at 600,000 each year, the CDC reports.

Large outbreaks of pertussis have occurred in health care facilities through failure to recognize and isolate infected infants and children, failure to recognize and treat disease in staff members, and failure to institute infection control measures rapidly.1 Expensive and time-consuming follow-up in such cases may include work furloughs for some workers and post-exposure prophylaxis with antibiotics.

The recommendations approved by HICPAC state that "Health care personnel who work in hospitals or ambulatory care settings and have direct patient contact should receive a single dose of Tdap as soon as feasible if they have not previously received Tdap. Priority should be given to vaccination of health care personnel with direct contact with infants aged younger than 12 months old. An interval as short as two years from the last dose of Td is recommended for the Tdap dose. Other health care personnel (i.e., those who do not work in hospitals or ambulatory care settings or who do not have direct patient contact) should receive a single dose of Tdap according to the routine recommendation and interval guidance for use of Tdap among adults. However, these personnel are encouraged to receive the Tdap dose at an interval as short as two years following the last Td. Hospitals and ambulatory care facilities should provide Tdap for health care personnel and use approaches that maximize vaccination rates such as education about the benefits of vaccination, convenient access, and provision of Tdap at no charge."

Long-term care a 'hot-button' issue

In a unanimous vote described as a "slam-dunk" by one committee member, ACIP approved the recommendations with little discussion at a Feb. 22 meeting in Atlanta. However, questions were raised in the HICPAC discussions about why the recommendations did not include health care workers who care for residents of long-term care facilities. "I don't understand the exclusion of long-term care," said Michael Tapper, MD, a liaison HICPAC member representing the Society for Healthcare Epidemiology of America (SHEA). In particular, the exclusion of health care workers working in long-term pediatric care "makes no sense," he added.

"Long-term care became something of a hot-button item," said M. Patricia Joyce, MD, an epidemiologist in the CDC center for immunization and respiratory disease. "[The issue] was whether or not facilities were really at risk and would they consider it important for their employee health program to provide this vaccine. Because of some disagreement, it was really not addressed as such. It was somewhat controversial. I can tell you as an infectious disease person, I felt that it was a good idea. There were others however that felt the cost could not be justified, particularly for adult long-term care. Although there are reports of outbreaks, the risk is low enough for some to question the costs. This came from various stakeholders."

Though the CDC is trying to jump-start immunizations in hospitals, long-term care employees are not really being "excluded" since the vast majority of them would be covered by a previously approved general recommendation to immunize adults younger than 65 years against pertussis.

"I share your concerns, but we tried to make these evidence based as best we could," Trudy Murphy, MD, a medical epidemiologist with the CDC national immunization program, told Tapper. "But we do not have data to support what you believe and we probably all believe. Please give us the data."

As a liaison member, Tapper had no vote on the issue, but one voting member of HICPAC gave a thumbs down to the recommendations.

Philip W. Smith, MD, chief of infectious diseases at the University of Nebraska Medical Center in Lincoln, voted against the recommendations after questioning whether there was sufficient data to support vaccinating health care workers who were not involved in direct patient care.

Mark Russ, MD, MPH, liaison member to HICPAC representing the American College of Occupational and Environmental Medicine (ACOEM), supported the recommendations but underscored that they come at no small cost. "This is a large and expensive recommendation, probably a $300 million recommendation," he said. "In hospitals, it will often be the occupational medicine clinicians in cooperation with infection control personnel who need to pitch this to hospital administrators. ACOEM is taking the position that health care workers with direct patient contact should receive this vaccine. I think the strength on which to pitch it [to hospital administrators] is that this is a disease that kills otherwise healthy infants. Hospitals administrators are attuned to patient safety."

Indeed, the recommendations emphasize that health care workers who care for infants younger than 12 months old should be the top priority to receive the pertussis vaccine. With regard to cost, the CDC guidelines emphasize that the cost of controlling nosocomial pertussis is high — regardless of the size of the outbreak. "The impact of pertussis on productivity can be significant, even when no secondary case of pertussis occurs," the guidelines state. "The hospital costs result from employee time to identify and notify exposed patients and personnel, from providing prophylactic antimicrobial agents for exposed personnel, laboratory testing and treating symptomatic contacts, furlough of symptomatic personnel, educating personnel, communicating with health care personnel and the public, employee time for control efforts, and lost time from work for illness."

CDC projected cost benefits indicate that every dollar invested in pertussis vaccine will reap $2.40 for the institution in prevented infections, exposures, and infection control measures. The CDC model is based on a recently published study of 17 symptomatic cases of pertussis among health care workers that resulted from exposure to an infant who was later confirmed to have pertussis.2 The health care workers in turn had 307 close contacts, so the hospital had to implement extensive infection control and follow-up measures. Investigators determined costs by interviewing infection control and hospital personnel, reviewing billing records, and surveying symptomatic workers. They calculated the benefits and costs of a vaccination program for health care workers using a model to estimate the number of pertussis exposures that would require control measures annually. The cost of the outbreak was $81,382, including costs incurred by health care workers of $6,512.

References

  1. Weber DJ, Rutala WA. Management of healthcare workers exposed to pertussis. Infect Control Hosp Epidemiol 1994; 15(6):411-415.
  2. Calugar A, Ortega-Sanchez IR, Tiwari T, et al. Nosocomial Pertussis: Costs of an outbreak and benefits of vaccinating health care workers. Clin Infect Dis 2006; 42:981-988.