A 24 Month Observational Study of Infants 3-24 Months, Who Suffer an Acute Episode of Respiratory Infection and Wheezing Illness

BACKGROUND: Respiratory virus infections are extremely common in young children. These
infections typically lead to inflammation and constriction of the airways, which is termed
bronchiolitis. Bronchiolitis is the leading cause of hospitalization for infants with
respiratory infections, with an average of 120,000 children under the age of one hospitalized
every year. Viral infection by Respiratory Syncytial Virus (RSV), rhinoviruses, or influenza
viruses is thought to be by far the major driver of bronchiolitis. The children who need to
be hospitalized with bronchiolitis have a drastically increased chance (about 45%) of
developing chronic respiratory diseases such as wheezing or asthma. The disease of asthma
affects children more than adults, and the Centers For Disease Control states that asthma is
the most chronic condition among children under the age of 18, affecting more than 6 million
(or 8.4%) children in the US. Due to this prevalence, asthma is the third leading cause of
hospitalization among children under the age of 15 years, with the annual direct healthcare
costs at ~$50 billion every year. The economic costs associated with parental lost
productivity is another ~$6 billion every year. The American Lung Association states that
asthma is also one of the leading causes of school absenteeism, with an estimated 13.8
million lost school days every year. While asthma can be managed with bronchodilator
inhalers, there is not a single treatment designed to prevent or reverse asthma disease.
Understanding how viral infection causes initial bronchiolitis and maintains the chronic
inflammation that leads to asthma will lead to new treatments that prevent or reverse chronic
lung diseases. This research has the potential to change everyday life for millions of
children and their families in the US.

Inclusion Criteria:

- Documented informed consent from legal guardian prior to study procedures

- Age: 3-24 months at the time of visit 1

- Severe lower respiratory wheezing illness confirmed by auscultation requiring
hospitalization or acute care (Emergency Department care or unscheduled ambulatory
care)

Exclusion Criteria:

- No prior hospital admissions for wheezing illnesses

- No prior diagnosis of asthma or Reactive Airways Disease

- More than 1 prior episode of wheezing confirmed by auscultation

- No congenital or chronic disease which would negatively affect the conduct of the
study (e.g. childhood cancer, cystic fibrosis, interstitial lung disease, prior
aero-digestive surgery)

- No diagnosis of bronchopulmonary dysplasia

- No premature birth (gestational age < 32 weeks)

- Daily treatment with a daily asthma controller (e.g. Montelukast, inhaled
corticosteroid)