Board Review: Internal Medicine


A 34 year-old previously healthy female presents to the Emergency Department with a sore throat, myalgias, cough, headache, and fevers for the past five days. Cough is productive of white sputum, and she has noted some flecks of blood over the past day. Patient works as a veterinary technician and reports her co-worker has been sick with similar symptoms. She denies any recent animal bites. Vitals signs: Temp 39.4C, HR 121, BP 110/65, RR 18, Sp02 94% on room air. On exam, the patient appears short of breath and uncomfortable. There are rales auscultated throughout all lower lung fields. Chest x-ray shows multifocal pneumonia. What is the most appropriate antibiotic treatment for this patient?


  1. Augmentin plus Amoxicillin
  2. Doxycycline

  3. Levaquin

  4. Rifampin












Answer: B- Doxycycline

This patient is presenting with upper respiratory symptoms that are concerning for zoonotic infection given the patient works as a veterinary technician. Chlamydia psittaci is an obligate intracellular organism that is transmitted through various bird species. Infection leads to generalized symptoms such as fever, myalgias, headaches, with late onset cough. Ultimately if untreated, patients are at a high risk of developing sepsis. Diagnosis is made by serologic testing. Treatment is doxycycline 100mg BID. Other organisms to consider in patients with this presentation include mycoplasma, legionella, coxiella burnetii, leptospirosis, and brucellosis. 




Hogerwerf, L., DE Gier, B., Baan, B., & VAN DER Hoek, W. (2017). Chlamydia psittaci (psittacosis) as a cause of community-acquired pneumonia: a systematic review and meta-analysis. Epidemiology and infection, 145(15), 3096–3105.

Kitch B.B., & Meredith J.T. (2020). Zoonotic infections. Tintinalli J.E., & Ma O, & Yealy D.M., & Meckler G.D., & Stapczynski J, & Cline D.M., & Thomas S.H.(Eds.), Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw Hill.

Knittler, M. R., & Sachse, K. (2015). Chlamydia psittaci: update on an underestimated zoonotic agent. Pathogens and disease, 73(1), 1–15.