Pertussis deaths: report of 23 cases in the United States, 1992 and 1993.

OBJECTIVE

To characterize pertussis deaths and to identify possible risk factors and prevention strategies.

METHODS

A retrospective review of all deaths attributed to pertussis with disease onset during 1992 and 1993 reported to the Centers for Disease Control and Prevention. Hospital discharge summaries and autopsy reports were reviewed, and additional clinical information was provided by physicians involved in the care of the children.

RESULTS

During 1992 and 1993, 23 deaths attributed to pertussis were reported to the Centers for Disease Control and Prevention. Cultures for Bordetella pertussis were positive in 18 (90%) of the 20 cases in which it was performed. Twenty (87%) of the 23 children who died were young than 1 year of age, and 18 (78%) of the children had received no doses orf pertussis vaccine. Among 20 children for whom gestational ages were known, 12 (60%) were born at36 weeks' gestation or earlier; in contrast, 10.7% of live births in the United States in 1992 were at 36 weeks' gestation or earlier. The median age of mothers whose children had fatal pertussis was 20 (range, 14 to 37) years in the 15 cases in which ages were known, compared with the national median age of 26.3 years in 1992. Pneumonia was a complication in all but 1 (96%) of the cases. Seizures occurred in 4 cases (17%), and acute encephalopathy occurred in 3 cases (13%).

CONCLUSIONS

Pertussis continues to cause serious illness and death in the United States, particularly among infants who are not vaccinated. Preterm delivery and young maternal age may place infants at increased risk of death because of pertussis. Under the current pertussis vaccination schedule, three fourths of the infants who died were too young to have received three doses of pertussis vaccine, the minimum number of doses considered necessary for adequate protection against clinical pertussis. Additional strategies, to prevent deaths caused by pertussis in young infants, such as starting infant vaccination at an earlier age and booster doses to adolescents and adults, need to be evaluated.