NBME 18 questions (spoilers)

A 63-year-old man with mild emphysema who has smoked 1 pack of cigarettes daily for 45 years has the sudden onset of headache, myalgia, and rising temperature. A dry cough develops, with chills and chest pain. Examination of Gram stain of sputum discloses neutrophils, but bacteria are not evident. An x-ray of the chest is consistent with severe pneumonia. A culture of the sputum is negative, but a culture of a bronchoscopy specimen on a highly specialized bacteriologic medium yields gram-negative rods. The identity of these bacteria is confirmed by staining with specific fluorescent antibodies. The patient responds to therapy with a macrolide antibiotic. This infection was most likely acquired from which of the following?

a Inhalation of aerosols from environmental source

b Inhalation of bird droppings

c Inhalation of respiratory secretions from infected animal

d Inhalation of resp secretions from infected person

e Patient's normal flora


Current thinking: The fact that it doesnt gram stain points to chlymidia or mycoplasma. His clinical picture suggests not mycoplasma since his symptoms look bad (usually xrays look worse than symptoms). Also it eventually stained gram negative and mycoplasma is not gram anything since it has no cell wall?

So chylmidia = from a parrot = from infected animal? What do you think

edit: "Respiratory secretions transmit C pneumoniae from human to human, whereas infected birds transmit C psittaci to humans via a respiratory route through direct contact or aerosolization"

So not sure if C or D. I picked D on the exam thinking it was something else and it was wrong. No history of interacting with birds tho so wtf maybe not chlymidia after all

/r/medicalschool Thread