Pertussis transmits from family members

More than three quarters of pertussis (whooping cough) cases are transmitted from family members to infants. In the United States, the incidence of pertussis, in infants has tripled in the past two decades despite widespread vaccination coverage. The Advisory Committee on Immunisation Practices (ACIP) recommends that all adolescents and adults receive a pertussis booster shot. Researchers from the University of North Carolina at Chapel Hill analysed how infants are catching pertussis. They collected comprehensive data on close contacts of a group of infants with laboratory-confirmed pertussis. They found evidence that household members are responsible for 73 percent to 82 percent of whooping cough transmission to infants for whom a source case could be identified and for 39 percent of transmission to all infants with pertussis in this study. Parents were the most common source of pertussis infection, followed by siblings, aunts and uncles, friends and cousins, grandparents, and part-time caretakers. It is therefore likely that the implementation of the recent ACIP recommendation for adult and adolescent vaccination could substantially reduce the burden of infant pertussis, if high coverage rates among those in contact with young infants can be achieved.