Childhood asthma after bacterial colonization of the airway in neonates
Hans Bisgaard1, Mette Northman Hermansen, Frederik Buchvald
1Danish Pediatric Asthma Center, Copenhagen University Hospital, Gentofte, Copenhagen. bisgaard@copsac.dk
Insights
Neonatal hypopharyngeal colonization with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis increases the risk of recurrent wheeze and early-life asthma in children. This early bacterial exposure is linked to later respiratory issues.
Area of Science:
- Pediatric respiratory medicine
- Microbiology
- Immunology
Background:
- Severe recurrent wheeze in young children is linked to bacterial colonization and early asthma development.
- Investigating the association between neonatal hypopharyngeal bacterial colonization and later wheeze, asthma, and allergy is crucial.
Purpose of the Study:
- To determine if asymptomatic neonatal hypopharyngeal bacterial colonization predicts recurrent wheeze, asthma, and allergy up to age 5.
- To explore the relationship between specific bacterial species and the development of these conditions.
Main Methods:
- Cultured hypopharyngeal aspirates from 321 neonates at 1 month of age for key bacteria.
- Prospectively monitored wheeze via diary cards and assessed allergy markers (IgE, eosinophils) at age 4.
- Diagnosed asthma and measured lung function at age 5.
Main Results:
- Neonatal colonization with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis (or combinations) was associated with persistent wheeze, severe exacerbations, and hospitalizations.
- Colonized infants showed increased blood eosinophil counts and total IgE at age 4.
- Asthma prevalence and airway reversibility were significantly higher in neonatally colonized children at age 5.
Conclusions:
- Neonatal hypopharyngeal colonization with S. pneumoniae, H. influenzae, or M. catarrhalis poses an increased risk for early-life recurrent wheeze and asthma.
- Early bacterial presence in the hypopharynx may be a significant factor in the pathogenesis of childhood asthma.
Background:
Pathological features of the airway in young children with severe recurrent wheeze suggest an association between bacterial colonization and the initiating events of early asthma. We conducted a study to investigate a possible association between bacterial colonization of the hypopharynx in asymptomatic neonates and later development of recurrent wheeze, asthma, and allergy during the first 5 years of life.
Methods:
The subjects were children from the Copenhagen Prospective Study on Asthma in Childhood birth cohort who were born to mothers with asthma. Aspirates from the hypopharyngeal region of asymptomatic 1-month-old infants were cultured for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus. Wheeze was monitored prospectively on diary cards during the first 5 years of life. Blood eosinophil count and total IgE and specific IgE were measured at 4 years of age. Lung function was measured and asthma was diagnosed at 5 years of age.
Results:
Hypopharyngeal samples were cultured from 321 neonates at 1 month of age. Twenty-one percent of the infants were colonized with S. pneumoniae, M. catarrhalis, H. influenzae, or a combination of these organisms; colonization with one or more of these organisms, but not colonization with S. aureus, was significantly associated with persistent wheeze (hazard ratio, 2.40; 95% confidence interval [CI], 1.45 to 3.99), acute severe exacerbation of wheeze (hazard ratio, 2.99; 95% CI, 1.66 to 5.39), and hospitalization for wheeze (hazard ratio, 3.85; 95% CI, 1.90 to 7.79). Blood eosinophil counts and total IgE at 4 years of age were significantly increased in children colonized neonatally with S. pneumoniae, M. catarrhalis, H. influenzae, or a combination of these organisms, but specific IgE was not significantly affected. The prevalence of asthma and the reversibility of airway resistance after beta2-agonist administration at 5 years of age were significantly increased in the children colonized neonatally with these organisms as compared with the children without such colonization (33% vs. 10% and 23% vs. 18%, respectively).
Conclusions:
Neonates colonized in the hypopharyngeal region with S. pneumoniae, H. influenzae, or M. catarrhalis, or with a combination of these organisms, are at increased risk for recurrent wheeze and asthma early in life.
Related Concept Videos
01:20Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
01:29Asthma-I: Introduction
01:26Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
01:28Development of the Oral Microbiota
01:29Microbiota of the Respiratory Tract
01:28Asthma I: Introduction