A 7 week old girl is brought to the physician by her mother b/c of a 1 day hx of labored breathing. Her birth was uneventful, but her mother says that the pt developed conjunctivitis on the 5th day of life. Her temp is 37C and her resp rate is 40/min. Bilateral inspiratory crackles and a slight wheeze are heard on auscultation of the chest. A chest x-ray shows bilateral interstitial infiltrates with hyperinflation. Lab studies show leukocyte count of 15,000/mm3 with 40% eosinophils. What is your diagnosis?