Bordetella pertussis was uncommon among infants hospitalized with bronchiolitis during the winter season, as well as during interepidemic periods of pertussis, according to recent study results.
Pedro A. Piedra, MD, of the department of molecular virology and microbiology at Baylor College of Medicine, and colleagues set out to determine the prevalence for B. pertussis infection and to describe its clinical course among a cohort of U.S. children aged younger than 2 years hospitalized with bronchiolitis during three consecutive winter seasons between 2007 and 2010.
Pedro A. Piedra
“There is a strong interest in defining the role of B. pertussis in infants with bronchiolitis in the current era, because in both diseases the incidence is highest in infants, they cause life-threatening illness, symptoms can be atypical in young infants and have overlapping features in older infants, there are conflicting data on the prevalence of B. pertussis in bronchiolitis and molecular diagnostics have improved the detection of B. pertussis,” Piedra, an Infectious Diseases in Children Board Member, and colleagues wrote.
The study included infants admitted at one of 16 sites across 12 states. Of the 2,207 infants included in the analysis, 94% exhibited one or more respiratory pathogens. Specifically, B. pertussis was identified in only four cases (0.2%; 95% CI, 0.1%-0.5%), of which three had a viral coinfection. All four were aged younger than 4 months; two infants met the CDC definition of probable pertussis, and three received at least one dose of the acellular pertussis vaccine, according to study results.
Paroxysmal cough was detected in two infants during hospitalization, and one infant required ICU care with a median length of stay of 13 days.
Those with confirmed B. pertussis had similar characteristics to those who met the CDC clinical case definition of probable pertussis, most of which had 3 or more days of difficulty breathing at the time of hospitalization.
“In children hospitalized with bronchiolitis, B. pertussis should be considered in young infants who are slow to improve with conservative management and have an elevated white blood cell count,” the researchers wrote. – by Jennifer Southall
Disclosure: The researchers report no relevant financial disclosures.