The changing epidemiology of pertussis in young infants. The role of adults as reservoirs of infection
Nelson, J.D.
American Journal of Diseases of Children 132(4): 371-373
1978
ISSN/ISBN: 0002-922X PMID: 645653 Document Number: 133455
Bacteriologically confirmed pertussis (400 cases) in infants and children during the past 18 yr were reviewed. Several changes in the epidemiology occurred in the most recent 6 yr period. The incidence of whooping cough in children decreased by at least 50%, but the proportion of cases occurring in infants younger than 12 wk of age doubled to 30% of all cases. Formerly most young infants acquired their illness from siblings or other children, but in the recent period adults in the household were the most common source of infection to neonates and young infants. This observation plus the increasingly high level of immunization in preschool and school-aged children suggest that young adults with waning immunity and mild illness are a major immunity and mild illness are a major reservoir for transmission of pertussis to infants too young to be immunized.