Respiratory Syncytial Virus (RSV) Follow-Up Study (MK-0476-374)

An Observational Follow-Up Study of Pediatric Patients Who Participated in a Previous Respiratory Syncytial Virus (RSV)-Induced Bronchiolitis Study of Montelukast

This is a prospective, multicenter, observational study in participants who completed the 24-week, placebo-controlled MK-0476 Protocol 272 (NCT00076973) study of montelukast in the treatment of respiratory symptoms subsequent to RSV-induced bronchiolitis. The purpose of this study is to better understand the clinical and demographic correlates of asthma and atopic disorders in children (through the age of 6 years) with a history of severe RSV-induced bronchiolitis.

Inclusion Criteria:

• successfully completed MK-0476 Protocol 272
• had RSV-induced bronchiolitis at entry into Protocol 272

Exclusion Criteria:

• had developed or had been diagnosed with any illness or congenital disorder that could be immediately life threatening