An Epidemiological Study to Evaluate the RSV-Associated Lower Respiratory Track in Infections in Infants

• The primary objective of this study is to describe the incidence of RSV-associated LRI or apnea (% RSV positive) among infants <1 year of age presenting to the ED during selected shoulder months. The total number of events will also be described.
• To characterize the clinical outcomes and demographic data of infants presenting to the ED with RSV-associated LRI or apnea
• To characterize the social burden (in the form of number of days lost from work by parent/ guardian) for these infants through 14 days after the index ED visit and through hospital discharge will also be described.
• Based on a sample of cases collected in a cohort of patients enrolled at or near the peak of RSV disease during the traditional season, a comparison of the rate of RSV between shoulder and peak periods will be described.
• To describe the overall rates of RSV-associated LRI or apnea based on the general ED statistics collected during the entire study period.

Inclusion criteria

• Written informed consent from parent/guardian to participate in this study
• Male and female infants <1 year of age (child must be entered before his/her 1st birthday)
• Physician diagnosis of either a) acute LRI or b) apnea below:

A) Acute LRI, defined as:

• Medical diagnosis of bronchiolitis or pneumonia, or
• In the absence of either of these diagnoses, LRI will be determined by the investigator after review of the medical record and must include at least one of the following:

• Retractions
• Wheezing
• Rales or crackles
• The presence of a new infiltrate, if a chest X-ray is available, which must be diagnosed by the ED physician or radiologist

B) Apnea, defined as either:

• Cessation of breathing for >20 seconds by history or observation, or
• Cessation of breathing for any length of time if accompanied by cyanosis or pallor, bradycardia as detected by a monitor, or
• ED primary diagnosis of apnea

• Parent/guardian has the ability and willingness to be available for a follow-up interview by telephone

Exclusion criteria

• Use of palivizumab or RSV-IGIV at any time prior to enrollment
• Participation in trials of investigational RSV prophylaxis or therapeutic agents