A previously healthy 8-week-old infant is brought to the emergency department because of fever, fatigue, and difficulty breathing for one day. She has been feeding poorly since yesterday. She has also had nasal congestion for 2 day. She was born by uncomplicated vaginal delivery at 40 weeks' gestation. The patient has been treated with acetaminophen for the last 24 hours, and vitamin D drops since birth. She appears irritable, pale, and lethargic. She is at the 25th percentile for both length and weight; she had the same percentiles at birth. Her temperature is 38.2°C (100.7°F) and respirations are 64/min. Pulse oximetry on room air shows an oxygen saturation of 92%. Physical examination shows moderate subcostal retractions. Wheezing is heard on auscultation of the chest. Her hemoglobin concentration is 10.5 g/dL, leukocyte count is 13,000/mm3, and platelet count is 345,000/mm3. Which of the following pathogens is most likely causing this patient's condition?

Question

Quizplus · Accepted Answer

Eductional Objective: Viral bronchiolitis is most commonly caused by respiratory syncytial virus and presents with low-grade fever, cough, and respiratory distress (eg, tachypnea, retractions) in children age <2 years.  Examination typically shows diffuse wheezes and/or crackles.

A Previously Healthy 8-Week-Old Infant Is Brought to the Emergency