Tdap should replace Td for adults, says CDC committee.(Clinical Rounds)

ATLANTA -- The recommendation for using the new tetanus-diphtheria-acellular pertussis vaccine has been expanded to adults aged 19-64 years, according to a vote by the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices at its fall meeting.

The tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine, adsorbed (Tdap) was licensed in June for use as a single-dose booster immunization in persons aged 11-64 and was previously recommended by ACIP for use in adolescents. The routine interval for administering booster doses is 10 years.

This vaccine (Adacel, Sanofi-Pasteur), when used instead of the tetanus-diphtheria (Td) booster, will provide adults with immunity against pertussis with its associated morbidity, said Margaret M. Cortese, M.D., of the CDC's National Immunization Program.

Of the 26,000 cases of pertussis reported in 2004, 28% were among adults, and available data suggest that pertussis is endemic among U.S. adults, Dr. Cortese said.

The spectrum of illness in adults ranges from asymptomatic to classic pertussis with its paroxysmal cough and post-tussive vomiting. Many adults experience difficulty breathing and sleeping, weight loss, and urinary incontinence. The high-pressure coughing also has resulted in complications such as rib fractures, pneumothorax, pneumomediastinum, and herniated lumbar disks. There was one report from Canada of a man who had a carotid dissection from coughing.

Five deaths were reported in the United States between 1990 and 2004, all since 1997 and all in patients with underlying illness. "And as food for thought, there was a report from the Netherlands of an outbreak among elderly women living in a religious institution, where the attack rate was high, at 53%, and four deaths occurred," Dr. Cortese said. Three of the deaths resulted from acute intracranial hemorrhage following pertussis cough illnesses exceeding 100 days. This very prolonged cough is a common feature of pertussis in adults. "Almost everyone coughs for at least 3 weeks. The median in adults is about 2-3 months, with ranges from a couple of weeks to 32 weeks," she said.

Moreover, by the time the diagnosis is made, 50% of adult patients have been coughing for more than a month, which permits plenty of time for them to transmit the illness. Disease transmission, particularly to infants younger than 6 months, was a factor cited by ACIP's working group on pertussis in ...