Neonatal pertussis presenting as acute bronchiolitis: direct detection of the Bordetella pertussis genome using loop-mediated isothermal amplification.

We report a 28-day-old female infant with pertussis presenting as severe acute bronchiolitis with cyanosis. On admission, the patient's symptoms were similar to those of acute bronchiolitis. However, occasional apneic episodes with cyanosis and peripheral lymphocytosis suggested neonatal pertussis and prompted us to examine the presence of Bordetella pertussis using loop-mediated isothermal amplification (LAMP) based on the insertion sequence IS481. LAMP of the nasopharyngeal and intratracheal aspirates was positive for B. pertussis and a diagnosis of neonatal pertussis was made. As the clinical features of pertussis in neonates and early infancy are not characteristic, LAMP is a useful tool for rapid diagnosis of B. pertussis infection.