Bacterial Infections USMLE Step 1 Practice Questions
58 board-style USMLE Step 1 questions in Infectious Disease. Each question shows the correct answer; create a free account for the full explanation and adaptive practice.
- USMLE Step 1 · hard25. A 73 year old man presents with 2 weeks of low grade fever and malaise. One month ago he underwent transurethral resection of the prostate for urinary obstruction. Cardiac exami…
- USMLE Step 1 · easy26. A 9 year old boy is brought to clinic with fever, sore throat, and a diffuse erythematous rash that feels like sandpaper for 2 days. Examination shows pharyngeal erythema, tonsi…
- USMLE Step 1 · hard27. A 38 year old man with untreated HIV presents with fever, night sweats, weight loss, and chronic diarrhea. His CD4 count is 32 cells per microliter. Blood cultures grow acid fas…
- USMLE Step 1 · hard28. A 42 year old man recently immigrated from a high prevalence country and presents with months of cough, weight loss, evening fevers, and night sweats. Chest radiograph shows upp…
- USMLE Step 1 · medium29. A 29 year old man presents with a painless penile ulcer that appeared 10 days ago. He reports unprotected intercourse with a new partner 4 weeks earlier. Examination shows a cle…
- USMLE Step 1 · medium30. A 34 year old woman presents with several weeks of fatigue, migratory joint pain, and intermittent palpitations. Two months ago she removed a tick after hiking in Connecticut an…
- USMLE Step 1 · medium31. A 12 year old boy is brought to the clinic in July because of fever, severe headache, and myalgias after a camping trip in North Carolina. On examination he has a blanching rash…
- USMLE Step 1 · medium32. A 5-week-old male infant presents with staccato cough and tachypnea for 2 weeks. Vital signs show HR 160 bpm, RR 52/min, BP 85/55 mmHg, temp 37.2°C, SpO2 88% on room air. He fee…
- USMLE Step 1 · easy33. A 19 year old college student presents with low grade fever, malaise, and a persistent dry cough. Chest radiograph shows diffuse interstitial infiltrates that appear worse than…
- USMLE Step 1 · medium34. A 61 year old man presents with fever and diffuse abdominal pain 5 days after emergency surgery for a perforated appendix. CT scan shows multiple intraabdominal abscesses. Aspir…
- USMLE Step 1 · easy35. A 49 year old man presents with chronic epigastric pain that improves with meals but recurs several hours later. He has no weight loss or vomiting. Endoscopy shows a duodenal ul…
- USMLE Step 1 · medium36. A 22-year-old man presents with 3 days of fever (38.9°C), abdominal cramping, and bloody diarrhea after consuming undercooked chicken. Stool culture grows Campylobacter jejuni.…
- USMLE Step 1 · hard37. A 57 year old man with cirrhosis presents with fever, vomiting, and rapidly progressive painful swelling of the right leg after eating raw oysters the previous evening. Examinat…
- USMLE Step 1 · medium38. A 24 year old woman with cystic fibrosis is admitted for worsening cough, fever, and increased sputum production. Sputum culture grows an oxidase positive gram negative rod that…
- USMLE Step 1 · hard39. A 65 year old man develops fever, dry cough, watery diarrhea, and confusion 5 days after staying at a hotel. Temperature is 39.2 C (102.6 F). Chest radiograph shows patchy unila…
- USMLE Step 1 · medium40. A 4 year old unimmunized boy is brought to the emergency department for high fever, muffled voice, drooling, and respiratory distress. He is sitting upright and leaning forward.…
- USMLE Step 1 · medium41. A 6-year-old unvaccinated girl presents with severe paroxysmal coughing spells followed by inspiratory whooping and posttussive vomiting for 3 weeks. Vital signs: BP 98/62, HR 1…
- USMLE Step 1 · easy42. A 67-year-old man with severe COPD presents with increased sputum production, dyspnea, and wheezing. Vital signs show HR 102/min, RR 24/min, BP 138/86 mmHg, temperature 38.2°C,…
- USMLE Step 1 · medium43. A 23 year old woman presents with fever, migratory polyarthralgias, and several pustular lesions on the hands and feet. She is sexually active with inconsistent condom use. Pelv…
- USMLE Step 1 · medium44. A 19 year old college freshman is brought to the emergency department with fever, headache, vomiting, and confusion. He is hypotensive and has a diffuse petechial rash. Lumbar p…
- USMLE Step 1 · hard45. A 43 year old man with chronic granulomatous disease presents with headache and focal left arm weakness. MRI of the brain shows a ring enhancing lesion. He also has a chronic co…
- USMLE Step 1 · medium46. A 36 year old woman presents with several weeks of jaw pain and a slowly enlarging firm neck mass that began after a dental procedure. She also has a history of prolonged intrau…
- USMLE Step 1 · medium47. A 32 year old pregnant woman at 29 weeks gestation presents with fever, myalgias, and diarrhea after eating unpasteurized soft cheese. Two days later she develops headache and n…
- USMLE Step 1 · medium48. A 7 year old unimmunized girl is brought to the clinic with fever, sore throat, and neck swelling. Examination shows cervical lymphadenopathy and a thick gray pharyngeal pseudom…