HCWs caring for infants need pertussis shot

Further HCW recommendations due in February

Health care workers caring for infants should receive the new pertussis vaccine, according to the recommendation of a federal advisory panel.

Amid concern about the risk to young children, the Advisory Committee on Immunization Practices (ACIP) targeted parents, caregivers, and health care workers caring for infants under 12 months old — even while further recommendations are pending that will focus on all health care workers with patient contact. ACIP recommendations shape the guidelines from the Centers for Disease Control and Prevention (CDC) in Atlanta.

Outbreaks of pertussis have caused concern across the country as waning immunity leaves adults and adolescents vulnerable to the disease. A recent serologic study indicates that pertussis is endemic among adults,1 according to the CDC.

In adults, the disease causes prolonged and intense coughing that can crack ribs or even lead to loss of consciousness. But the greatest risk is to infants who have not yet been vaccinated or haven't received the full dosing schedule. From 2000 to 2004, 92 infants died of pertussis, almost all them under 6 months of age.

Infants younger than 6 months also accounted for more than half the hospitalizations in a pertussis outbreak in Wisconsin in 2004, according to the CDC.

"Having a baby on my floor with pertussis is the scariest thing in the world. It's a very bad disease," says Jane Siegel, MD, a professor of pediatrics and infectious disease specialist at the University of Texas Southwestern Medical Center in Dallas, who says she will begin discussing pertussis vaccination plans with her administration.

The Mayo Clinic in Rochester, MN, began offering the pertussis vaccine to health care workers this year during the annual flu vaccine clinics. With pertussis spreading in the community, the vaccine will help prevent health care workers from becoming a vector of the disease in the hospital, particularly endangering infants, says William Buchta, MD, MPH, medical director of Mayo's employee occupational health service.

"The problem is you can't really distinguish it from a regular cold," says Buchta. "By the time people have been identified, they usually have been communicating the bacteria for days or weeks."

Vaccination also benefits health care workers and their family members. While deaths among adults are rare, symptoms can be severe. Surveillance in Massachusetts found that almost half (47%) of adults had post-tussive vomiting and 41% had the classic "whooping cough."2

An outbreak investigation in South Carolina uncovered the case of one man who was exposed to pertussis from a co-worker at his office. He then transmitted it to his 3-month-old child. His own illness contributed to a car accident in which he suffered a severe coughing spell while driving and lost consciousness. He was not seriously injured, says Margaret Cortese, MD, a medical epidemiologist with the National Immunization Program (NIP) and a lieutenant commander with the U.S. Public Health Service.

"Not everyone has [a case] as distressing as that, but some adults do," she says.

While the need for an adolescent and adult pertussis vaccine has been well documented, some other issues remain less certain.

What if the health care worker has recently received a tetanus booster? ACIP says that the acellular pertussis vaccine (Tdap), which is combined with tetanus and diphtheria vaccines, can be given two or more years after a tetanus booster. However, some facilities have taken a more conservative approach. At Mayo, for example, employees may receive the pertussis vaccine five or more years after a tetanus booster.

The acellular pertussis vaccine, which is produced by Sanofi Pasteur and GlaxoSmithKline, has been approved only as a single dose. There are as yet no recommendations for future Tdap boosters.

An ACIP working group is also considering how the vaccine could best be incorporated into hospitals and other health care settings, and further recommendations are expected in February. But for now, the CDC still recommends post-exposure prophylaxis for health care workers who have a known exposure to pertussis — even if they have received the vaccine.3

"This is an issue that needs to be addressed and clarified," says Katrina Kretsinger, MD, MA, an NIP medical epidemiologist and a lieutenant commander with the U.S. Public Health Service.

Meanwhile, CDC epidemiologists are collecting survey information from hospitals around the country to determine how they have been impacted by pertussis. Those data may shape recommendations and could illustrate the need for health care worker vaccinations. "If we can demonstrate what the burden is then we have a much stronger case [with hospital administration]," says Siegel.

References

1. Baughman AL, Bisgard KM, Edwards KM, et al. Establishment of diagnostic cutoff points for levels of serum antibodies to pertussis toxin, filamentous hemagglutinin, and fimbriae in adolescents and adults in the United States. Clin Diagn Lab Immunol 2004; 11:1045-53.

2. Lee GM, Lett S, Schauer S, et al. Societal costs and morbidity of pertussis in adolescents and adults. Clin Infect Dis 2004; 39:1572-80.

3. 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(RR-18):1-42.