[The interactions between microorganisms and the small airways. A paediatric focus]

Area of Science:

• Infectious Diseases
• Pediatric Pulmonology
• Immunology

Background:

• The landscape of respiratory viruses is dynamic, with emerging zoonotic and novel viruses frequently identified.
• The link between viral infections like rhinovirus and asthma development is increasingly understood through birth cohort studies.
• The role of bacterial infections in the natural history and development of asthma in early childhood is gaining recognition.

Purpose of the Study:

• To explore the expanding spectrum of emerging respiratory viruses and their origins.
• To elucidate the relationship between viral infections, particularly rhinovirus, and the predisposition to asthma.
• To investigate the impact of bacterial colonization and infection on the development of asthma in young children.

Main Methods:

• Analysis of emerging respiratory virus characteristics and origins (zoonotic, novel identification techniques).
• Prospective follow-up of birth cohorts to understand bronchiolitis and asthma relationships.
• Utilizing data from the COPSAC Danish cohort to assess bacterial identification during wheezy episodes and early colonization impact.

Main Results:

• Rhinovirus is now a predominant respiratory virus compared to respiratory syncytial virus.
• Identified predisposing factors (immunological, atopic, genetic) suggest viral infections reveal asthma predisposition.
• Bacterial identification during early wheezy episodes and colonization at one month significantly impacts asthma onset by age five.

Conclusions:

• Viral infections, especially rhinovirus, may trigger asthma in genetically predisposed individuals.
• Early-life bacterial colonization and infections are crucial factors in the development of asthma.
• Further research is needed to understand the role of bacteria in severe pediatric asthma.