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Among infants since 1980
Pertussis Deaths Increased by 52%

Heidi Splete

Incidence of pertussis among infants younger than 4 months of age has increased since 1980, said Dr. Charles R. Vitek and his colleagues at the Centers for Disease Control and Prevention, Atlanta.

Based on analysis of pertussis cases reported to the CDC, infants too young to be protected by immunization may be at increased risk of contracting fatal pertussis (Pediatr. Infect. Dis. J. 22[7]:628-34, 2003).

Overall, deaths from pertussis in infants younger than 12 months of age increased by 52% from a total of 61 in the 1980s to a total of 93 in the 1990s. Either the presence of a Bordetella pertussis isolate or the presence of clinical symptoms compatible with pertussis qualified a death as pertussis related.

Significantly more infants younger than 4 months of age died from pertussis between 1990 and 1999 than between 1980 and 1989: 84 vs. 49.

Children need at least two to three doses of pertussis toxoid-containing vaccine for effective protection. Since the current U.S. vaccination schedule calls for doses of pertussis toxoid-containing vaccine at 2, 4, and 6 months, most infants younger than 4 months of age have not had enough vaccine to protect them and new strategies to prevent pertussis in young infants are needed, the researchers said.

Prematurity was strongly associated with infant pertussis deaths in the 1990s. Of 76 cases with available gestational information, 51% occurred in infants born at less than 37 weeks' gestation. In addition, Hispanic ethnicity may have been associated with infant pertussis deaths: the number of deaths per million infants was 4.77 for Hispanics, compared with 1.8 for non-Hispanics. As to the source of infection, the records of 46 cases showed exposure to infected persons including parents, siblings, and other household members.