ATLANTA — Pertussis in adolescents is an increasingly reported problem across the United States, Margaret M. Cortese, M.D., said at a meeting of the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices.
Preliminary data for 2004 include 8,000 cases reported in adolescents, with large numbers in Wisconsin, upstate New York, Colorado, and Massachusetts. More than 100 cases were reported in adolescents in each of 16 states, while 14 states reported more than 500 cases each in persons of all ages. Moreover, although reporting rates have increased, “these numbers are likely only a portion of the true burden,” said Dr. Cortese, a medical officer with the CDC's National Immunization Program.
Her presentation was among the discussion points during a 4-hour session at the Advisory Committee for Immunization Practices (ACIP) meeting devoted to issues surrounding the pertussis disease burden and to the anticipated licensure of two new reduced-antigen tetanus-diphtheria-acellular pertussis (Tdap) vaccines formulated for use in adolescents.
Both candidate vaccines—Sanofi-Pasteur's Adacel and GlaxoSmithKline's Boostrix—will be reviewed this month by the Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee, and ACIP is expected to issue recommendations later this year for their use as adolescent boosters.
In Massachusetts—which is the only state that conducts active surveillance for pertussis using a standardized serologic test for diagnosis—there were 1,088 cases of pertussis among adolescents in 2003, compared with 374 in 2002, 331 in 2001, and 869 in 2000. Of those cases, between 45% and 50% were involved in school outbreaks, Dr. Cortese reported.
Because Massachusetts has such an aggressive surveillance and reporting system for pertussis, their rates are typically about 20 times higher than the reported rates of any other state and “probably give a true indication of the rest of the country,” she noted.
Previously published data have documented significant morbidity and high costs associated with pertussis in adolescents. Among 314 children aged 10–17 years identified in Massachusetts, paroxysmal cough was reported in 74%, difficulty sleeping in 77%, difficulty breathing in 72%, post-tussive vomiting in 56%, and weight loss in 33%. A total of 38% were still coughing at the last interview, done a mean 3.4 months following the initial diagnosis (Clin. Infect. Dis. 2004;39:1572–80).
Those 314 were a subset of a larger group of 1,679 adolescents in whom various cost parameters were assessed. The teenagers made a median of two office visits, and 83% reported missing a mean 5.5 school days, while 43% of their parents/caretakers missed a mean 2.4 days of work. Average medical cost (including office visits, chest x-rays, and antibiotics) per case was $256, and average nonmedical cost (mostly in missed work) was $160.
These estimates don't include the costs of prophylactic antibiotics for contacts or the public health response, Dr. Cortese noted.