Background: Tetanus, diphtheria and acellular pertussis (Tdap) immunization of infant contacts (cocooning) is recommended by Centers for Disease Control and Prevention to prevent infant pertussis. We determined whether implementing a cocooning program at Ben Taub General Hospital (BTGH), Houston, reduced severe pertussis in young infants.
Methods: Infants <= 6 months of age, diagnosed with pertussis (determined by ICD-9 codes and microbiology records) at four hospitals, and born at times when only postpartum women (January 2008 through May 2009) and all infant contacts (June 2009 through August 2011) were offered Tdap at BTGH were compared with infants born pre-interventions (May 2004 through December 2007).
Results: 196 (49%) infants with pertussis were born pre-intervention, 140 (35%) during maternal postpartum (PP) and 64 (16%) during cocooning (C) periods. Infants were similar in age at diagnosis (81.2 vs 71.3 [PP] vs 72.5 [C] days; P 0.07), sex (male 59% vs 51% [PP] vs 48% [C]; P 0.17), hospitalization (68% vs 71% [PP] vs 78% [C]; P 0.27) and outcome (2 deaths in PP period; P 0.15), but more were admitted to intensive care units during C (24% vs 35% [PP] vs 68% [C]: P < 0.001). Similar proportions of infants were born at BTGH throughout the study (8% vs 9% [PP] vs 5% [C]; P 0.53).
Conclusions: Postpartum immunization and cocooning did not reduce pertussis illness in infants <= 6 months of age. Efforts should be directed towards increasing Tdap immunization during pregnancy, combined with cocooning, to reduce life-threatening young infant pertussis.
(C) 2014 by Lippincott Williams & Wilkins, Inc.