Vaccinate caregivers against pertussis

Newly approved vaccine has high success rate

Pertussis (whooping cough) is the only preventable infectious disease that has been steadily increasing in reported cases over the past 30 years, and for that reason the Centers for Disease Control and Prevention (CDC) has recommended that health care workers who have direct patient contact be vaccinated with a single dose of a new tetanus, diphtheria, and pertussis vaccine (TDaP).

A low of 1,010 pertussis cases was reported in 1976, compared to 25,827 cases in 2004, according to the CDC. Age group distribution also has changed, with adolescents and adults comprising an increasing proportion of the total.

Health care personnel are considered high risk for pertussis exposure. Pertussis in its early stages is indistinguishable from other upper respiratory infections, and in several cases the CDC has documented the spread of the disease among hospital workers and patients.

A person is considered exposed to pertussis if there is inhalation of droplets and discharges from the respiratory tract of an infected person. This can occur if you are within three feet of a patient and you are not wearing a mask. Adding to health care workers' risk of exposure is the fact that pertussis patients are most contagious during the early stages of the disease, before the onset of the tell-tale cough, when symptoms mimic a respiratory infection.

While pertussis is rarely a serious illness in adults, in young children it can be life-threatening. With CDC surveys indicating that 90% of personnel at pediatric hospitals surveyed had been exposed to pertussis during the previous five years, the recommendation was made that health care workers be vaccinated with the newly licensed TDaP vaccine, Adacel (sanofi pasteur, Toronto). (See box below, for CDC recommendations.)

Pertussis Recommendations

• Health care personnel with direct patient contact should receive a single dose of the tetanus, diphtheria, pertussis (TDaP) vaccine, Adacel, as soon as possible if they have not previously received it.

• While tetanus/diphtheria booster shoots (Td) are generally given every 10 years, health care personnel may receive the TDaP vaccine as soon as two years after their last Td booster.

• Health care personnel who do not have direct patient contact should receive a single dose of TDaP to replace the next scheduled Td booster.

• In the event that the supply of vaccine should need to be rationed, the Centers for Disease Control and Prevention recommends that priority be given to health care workers who have direct contact with pediatric patients younger than 12 months and other vulnerable patient populations.

Source: Centers for Disease Control and Prevention. MMWR 2006; 55(RR-17):1-33.

Business as usual at many hospitals

The new guidelines, appearing in the CDC's Dec. 18, 2006, Morbidity and Mortality Weekly Report, urge hospitals to vaccinate personnel who will likely have direct contact with patients. The TDaP vaccine is believed to be about 92% effective, based on studies in healthy adults, according to Tom Talbot, MD, MPH, chief hospital epidemiologist at Nashville, TN -headquartered Vanderbilt University Medical Center. The cost of the vaccine is $30 per dose, but the CDC estimates hospitals could save $2.38 for every dollar spent.

Many hospitals, particularly pediatric hospitals, already are observing the CDC guidelines.

David March, MHA, spokesman for Johns Hopkins Medicine in Baltimore, says his hospital has implemented the vaccination guidelines set out by the CDC, "but the manufacturer ran out [of vaccine]." March says vaccinations will resume when the hospital's supply is restocked. (According to the manufacturer, a brief shortage was experienced in late 2006, and orders were being accepted again as of mid-January 2007.)

Children's Hospital Boston learned first-hand in late 2006 the effect a pertussis outbreak could have on a facility, when a suspected 38 people — 36 adults and two children — fell ill with what rapid-result polymerase chain reaction (PCR) tests confirmed was pertussis. Children's implemented its protocol for pertussis exposure and confirmation by sending sick employees home for five days to complete an antibiotics course. State lab cultures used to confirm the initial PCR tests returned negative results on all the patients. Testing failed to determine conclusively what made the 38 people sick.

Beth Andrews, spokeswoman for Children's Hospital, says the experience ramped up the hospital's pertussis vaccine program, so the CDC guidelines will not affect its approach to vaccinating patient care staff. However, Talbot is leading a two-year study at Vanderbilt to find out if typical hospital protocol following pertussis exposure is necessary. Researchers will attempt to determine whether health care workers previously vaccinated for pertussis who are later exposed to someone infected with the disease require additional antibiotics, the current standard treatment. At Vanderbilt, as well as in other hospitals in the United States, the suggested treatment for an employee exposed to pertussis is a five-day antibiotics course. If the employee develops signs or symptoms of pertussis, further antibiotic treatment is administered while the employee is furloughed from work.

While the CDC says TDaP is 92% successful in healthy adults, it is unknown whether the chemical prophylaxis still is necessary, Talbot says. "The lingering question is whether we still need the antibiotics after exposure," he says.

While the vaccine has a high success rate, Talbot says, exposed health care workers still might harbor bacteria in their throats after exposure, bacteria that then could be passed on to other patients. "What we can see is asymptomatic transmission," he says. Another part of the pertussis protocol that Talbot is testing is whether the furlough is necessary after immunization. "What we're going to do is vaccinate a huge population [of Vanderbilt Medical Center employees] and follow them for about two years," Talbot explains.

According to the CDC guidelines, adults age 19-64 years should receive a single dose of TDaP, which replaces a single dose of Td (tetanus-diphtheria) vaccine for booster, if they received their last dose of Td more than 10 years ago.

Health care workers in hospitals or ambulatory care settings who have direct patient contact should receive a single dose of TDaP as soon as feasible, provided they have not already received the vaccine, according to the CDC guidelines.

Sources/Resources

For more information on prophylactic antibiotics in pertussis exposure, contact:

  • Thomas R. Talbot, MD, Chief Epidemiologist, Vanderbilt University Medical Center, Nashville, TN. Phone (615) 322-2035.E-mail: tom.talbot@Vanderbilt.edu.