Infants with whooping cough were most likely infected by the people they live with, according to a multicountry study led by researchers from the University of North Carolina, Chapel Hill

USA Today (Society for the Advancement of Education), Oct, 2007

Infants with whooping cough (pertussis) were most likely infected by the people they live with, according to a multicountry study led by researchers from the University of North Carolina, Chapel Hill. Parents were the source in 55% of affected infants. In all, household members were responsible 75% of the time.

Pertussis is a highly contagious bacterial infection. Although vaccination has reduced the number of reported cases in industrialized countries by more than 95% from what it was in the 1950s. the caseload in the U.S. has tripled in the past two decades.