In the 2014 pertussis epidemic in California, the burden of disease was highest for Hispanic infants and non-Hispanic white teenagers aged 14-16 years, researchers from the California Department of Public Health reported.

Pertussis incidence was 207 per 100,000 population for Hispanic infants less than 12 months old and 166.2 cases per 100,000 in white 14- to 16-year-olds, compared with an overall incidence of 26 cases per 100,000 for the period from Jan. 1 to Nov. 26, 2014. White, non-Hispanic infants and black infants also had rates over 100 per 100,000, noted Kathleen Winter and her associates of the California Department of Public Health (MMWR 2014;63:1129-32).

“The peak age of disease incidence beyond infancy increased to age 14-16 years in 2014, compared with the peak among children aged 10 years during” an earlier pertussis epidemic in 2010, they wrote. “Children and teenagers born in the United State since 1997 have only received acellular pertussis vaccine, and the upper age of this cohort correlates with the peak age in incidence during both epidemic years.”