Infectious Diseases Questions

A 45-year-old male on standard four-drug therapy for pulmonary tuberculosis presents for follow-up visit. He reports asymptomatic reddish-orange discoloration of his urine over the past week. Physical exam is unremarkable.
Which of the following medications is most likely responsible for this side effect?

A 31-year-old man presents to the emergency department with few days history of fever, pleuritic chest pain, and worsening shortness of breath. He has no significant medical history. Examination reveals several non-tender, erythematous macules on the palms. Cardiac auscultation demonstrates regular tachycardia, high-pitched opening snap, and low-pitched, late diastolic rumble best heard at the apex with the patient in the left lateral position.
Which one of the following is the most appropriate next step in management?

A 27-year-old nurse presents for a routine employment health evaluation prior to contract renewal. She reports no symptoms, and her physical examination is normal. Laboratory results are within normal limits. As part of occupational screening, after 48 hours, tuberculin skin test demonstrates the induration measures 12 mm in diameter.
Which of the following is the most appropriate next step in management?

A 36-year-old man presents to the clinic with two-week history of malaise, headache, and night sweats. He has no past medical history. He reports recent travel to multiple countries. Physical examination reveals oral thrush and tender cervical and inguinal lymphadenopathy.
Which one of the following is the most likely diagnosis?

A 49-year-old man presents to the clinic for preoperative evaluation. He has history of mechanical bicuspid aortic valve replacement performed five years ago. He is scheduled for elective right inguinal herniorrhaphy.
Which of the following represents the most appropriate antibiotic prophylaxis for his planned procedure?

A 57-year-old man being treated for pulmonary tuberculosis presents with bilateral fingertip paresthesias. His current regimen includes rifampin, isoniazid, pyrazinamide, and ethambutol. Neurologic examination within normal limits. A complete blood results are unremarkable.
Which one of the following is the most appropriate next step in management?

A 51-year-old man presents to the clinic with right-sided pleuritic chest pain and progressive dyspnea on exertion. He reports that his symptoms have gradually worsened over the past several weeks. He has associated anorexia and unintentional weight loss over the last 3 months. Chest radiograph reveals moderate right-sided pleural effusion. The Interferon-gamma release assay is positive. Pleural fluid analysis shows exudative effusion.
Which one of the following is the most likely diagnosis?

A 60-year-old man is admitted for management of infective endocarditis. He has prosthetic mitral valve placed 10 years ago. On admission, blood cultures grow methicillin-resistant Staphylococcus aureus.
Which of the following is the most appropriate antibiotic regimen for this patient?

A 32-year-old previously healthy female nurse presents to the clinic with fatigue and decreased appetite for the past several weeks. She reports no recent travel or drug use. Physical examination reveals no hepatosplenomegaly, jaundice, or signs of chronic liver disease. Initial laboratory testing shows a positive anti-HCV antibody test, but HCV RNA polymerase chain reaction is undetectable.
Which one of the following is the most appropriate next step in management?

A 35-year-old man presents to the emergency department with progressive dyspnea and fever. Physical examination reveals high-pitched, holosystolic murmur, loudest at the cardiac apex with radiation to the axilla. Inspection of hands shows subtle red discoloration beneath the fingernails.
Which one of the following is the most likely causative organism?

A 50-year-old woman presents to the emergency department with 3-day history of fever and progressive dyspnea. Cardiopulmonary and abdominal examinations are unremarkable. Examination of the extremities reveals tender, erythematous nodules on the pulps of several fingers. Further inspection of the distal phalanges shows discontinuous, splinter-like, dark-red linear lesions in the nail beds.
Which one of the following is the most likely diagnosis?

A previously healthy 38-year-old woman presents to the emergency department with two-day history of productive cough and fever. Her vital signs show temperature of 39.1◦C. Examination reveals crackles over the left lower lung field. No signs of pleural effusion or cyanosis. Chest X-ray shows left lower lobe consolidation.
Which one of the following is the most likely causative pathogen?

A 55-year-old man presents to the clinic for evaluation of persistent cough. He has no significant past medical history but reports 30-pack-year smoking history. A chest radiograph reveals cavitary lesion in the right upper lobe. Sputum microscopy demonstrates acid-fast bacilli.
Which one of the following is the most appropriate next step in management?

A 35-year-old male patient, recently arrived from India, presents with right upper quadrant abdominal pain and fever for three weeks. Laboratory results demonstrate elevated liver function tests and leukocytosis with neutrophil predominance of 70% and lymphocytes of 20%. Ultrasound reveals homogeneous hypoechoic mass in the liver.
Which one of the following is the most likely diagnosis?

A 65-year-old male with diabetes presents to the emergency department with one-week history of fever, dyspnea, and progressive productive cough with yellow sputum. On examination, he is tachypneic and hypoxic, with crackles in the right lower lung field. Chest X-ray reveals right lower lobe consolidation. He is admitted for IV antibiotics and supportive care.
What other empirical antibiotic should be given in addition to azithromycin?

A 39-year-old male with a history of diabetes presents to the clinic with eight-week history of persistent dry cough. He reports associated fever, night sweats, and unintentional weight loss. A chest radiograph demonstrates patchy opacity in the right upper lobe.
Which of the following is the most appropriate test to confirm the diagnosis?

A 42-year-old woman presents for preoperative evaluation for scheduled parathyroidectomy. Her medical history is significant for mitral valve prolapse with associated mitral regurgitation. She is concerned about her risk for infective endocarditis associated with the procedure.
What is the most appropriate intervention for infective endocarditis prophylaxis?

A 45-year-old man presents for follow-up six weeks after being started on four-drug regimen for pulmonary tuberculosis. He reports that his symptoms have fully resolved. A repeat sputum smear is negative for acid-fast bacilli. Laboratory test results are shown in the table.

Which one of the following is the most appropriate next step in management?

A 39-year-old man with HIV presents to the clinic. He reports eight-week history of dry cough that has now progressed to green sputum production over the past three days. He has associated dyspnea on exertion, 5-kg unintentional weight loss, and night sweats. A chest radiograph demonstrates apical patchy heterogeneous consolidations with poorly defined margins.
Which of the following is the most likely mode of transmission responsible for this patient’s condition?

A 61-year-old man with chronic kidney disease presents to the emergency department with three weeks of progressive fever, productive cough, and hemoptysis. He reports associated malaise, night sweats, and unintentional weight loss. On examination, there are focal crackles and dullness to percussion in the right upper lung field.
What is the most appropriate next step in management?

A 67-year-old man with diabetes, hypertension, and heart failure is admitted to the hospital for fever and cough. He is diagnosed with active pulmonary tuberculosis and is initiated on the standard four-drug regimen for planned six-month course. His current medications include carvedilol, lisinopril, furosemide, insulin, and warfarin.
Which one of the following is the most appropriate next step in management?

A smoker 52-year-old male presents to the emergency department with fever and productive cough with yellow sputum over the past 24 hours. He reports no recent travel and has no other medical history. Auscultation of the chest reveals scattered crackles at the right lung base.
Which one of the following is the most likely diagnosis?

A 39-year-old woman with diabetes presents to the clinic with chest pain, cough, and intermittent shortness of breath for the past few weeks. On examination, she has reduced breath sounds at the right lung base. A chest X-ray reveals a moderate right-sided pleural effusion. An interferon-gamma release assay is strongly positive.
Which one of the following is the most likely diagnosis?

A 51-year-old male with kidney disease presents to the clinic with three-week history of progressive fever, productive cough, and hemoptysis. He reports associated malaise, night sweats, and unintentional weight loss of 5 kg. On physical examination, there are focal crackles and dullness to percussion in the right upper lung field.
Which of the following is the most definitive test to confirm the suspected diagnosis?

A 38-year-old woman presents to the clinic for preoperative evaluation for scheduled dental extraction. Her medical history is significant for idiopathic hypertrophic subaortic stenosis. She is asymptomatic at rest.
What is the most appropriate intervention for endocarditis prophylaxis?

A 30-year-old man presents to the clinic for follow up visit. A chest imaging reveals right upper lobe cavitary lesion. Sputum acid-fast bacilli smear is positive. A diagnosis of pulmonary tuberculosis is made, and the decision is made to initiate standard four-drug regimen.
Before starting treatment, which of the following is the most important step?

A 34-year-old man is evaluated after initiating standard four-drug therapy for pulmonary tuberculosis. His medical history is significant for nephrolithiasis in first-degree relative. He reports recent onset of painless gross hematuria. Vital signs are normal. Laboratory findings revealed mildly decreased hemoglobin and platelets.
What is the most likely cause of the hematuria?

A previously healthy 32-year-old male presents to the emergency department with jaundice and right upper quadrant abdominal pain. Physical examination reveals scleral icterus and tenderness in the right upper abdomen. Laboratory tests show elevated liver enzymes.
Which of the following serologic markers is most indicative of acute hepatitis B virus infection?

A 63-year-old man presents to the emergency department with productive cough, fever, chills, and intermittent shortness of breath for few days. On examination, there is dullness to percussion and decreased breath sounds over the lower half of the right chest. The X-ray reveals consolidation in the right middle and lower lobes, along with moderate pleural effusion.
Which one of the following is the most likely diagnosis?

A 26-year-old man with history of poorly controlled epilepsy presents to the emergency department with 3-day history of productive cough with purulent sputum and fever. On examination, lungs are clear to auscultation bilaterally, no wheezing or crackles. Chest X-ray reveals patchy infiltrates in the posterior segments of the upper lobes.
Which one of the following is the most likely diagnosis?

A 72-year-old male is admitted to the ICU following hemicolectomy before 2 days. Over the past 6 hours, the nurse reports progressive decline in urine output despite fluid bolus. Vital signs reveal heart rate of 118 bpm and mean arterial pressure of 52 mmHg on norepinephrine. Physical examination demonstrates warm, well-perfused extremities.
Which type of shock is most consistent with this presentation?

A 61-year-old man presents to the emergency department with acute severe right foot pain for few hours. The patient was recently diagnosed with pulmonary tuberculosis on standard four-drug antitubercular regimen. On examination, the first metatarsophalangeal joint is erythematous and tender to palpation. Laboratory studies reveal elevated uric acid level.
Which of the following medications is most likely responsible for precipitating his acute gout attack?

A 70-year-old man presents with acute-onset pain and swelling in his left knee. His medical history includes rheumatoid arthritis, chronic obstructive pulmonary disease, and left total knee arthroplasty six years ago. On examination, the knee is erythematous, hot, tender, markedly swollen, and severely restricted range of motion.
Based on the findings, what is the most likely diagnosis?

A 65-year-old male is admitted to the hospital with a one-week history of fever and productive cough. Initial evaluation reveals crackles on auscultation, leukocytosis, and a chest X-ray demonstrating right lower lobe consolidation, consistent with community-acquired pneumonia. He is started on empiric antibiotics with clinical improvement over the next few days. However, over the past 12 hours, the patient has developed progressive dyspnea and worsening fatigue. A repeat chest X-ray shows a new moderate-sized pleural effusion on the right side.
Which one of the following is the most likely diagnosis?

A 71-year-old man presents with fever and productive cough. Examination reveals dullness to percussion and bronchial breath sounds in the right lower chest. Chest radiography shows right upper lobe infiltrate and moderate right pleural effusion. Thoracentesis is performed.
Which pleural fluid finding most strongly indicates the need for chest tube drainage?

A 60-year-old man is evaluated in the intensive care unit after undergoing coronary artery bypass grafting three days ago. Over the past 4 hours, he has developed progressive abdominal distension and diffuse pain. His temperature is 38.9°C, blood pressure is 90/60 mm Hg, and heart rate is 120 bpm. A pulmonary artery catheter, placed intraoperatively, reveals elevated cardiac output and low systemic vascular resistance.
Which of the following is the most likely diagnosis?

A 61-year-old woman with hypertension presents to the emergency department with one-week history of flu-like symptoms followed by cough. Initially, her cough was nonproductive but has progressed to scant white sputum over the past two days. Her vital signs show temperature of 38.1◦C. Auscultation of the chest reveals scattered crepitations in the right lung. Chest X-ray shows bilateral reticulonodular infiltrates with patchy opacities predominantly in the right middle lobe. Laboratory results demonstrate elevated reticulocyte count and positive cold agglutinins.
Which one of the following is the most likely diagnosis?

A 66-year-old woman with a history of diabetes presents to the emergency department with a one-day history of fever, myalgias, headache, and generalized malaise. Given recent reports of increased influenza activity in the community, an influenza rapid antigen test is performed and returns positive.
Which of the following infection control precautions is most appropriate for this patient?

A 27-year-old businessman presents with 2 days of progressive confusion followed by 5 hours of seizure activity. On examination, he is disoriented to time, place, and person. His history is significant for unprotected sexual activity over the past 6 months. Laboratory workup reveals positive serum cryptococcal antigen.
Which one of the following is the most likely diagnosis?

A 27-year-old businessman presents with 2 days of progressive confusion followed by 5 hours of seizure activity. On examination, he is disoriented to time, place, and person. His history is significant for unprotected sexual activity over the past 6 months. A serum cryptococcal antigen test is positive.
Which one of the following is the most appropriate next step in management?

A 24-year-old man presents with two-week history of watery diarrhea. He reports no fever, bloody stools, or recent travel. Physical examination is unremarkable. Stool microscopy shows no leukocytes, erythrocytes, or parasites.
Which one of the following is the most likely causative organism?

A 30-year-old man returns from Sudan presenting with high fever. Physical examination reveals mild jaundice and splenomegaly. A peripheral blood smear reveals ring-form trophozoites and some that appear as headphone shapes.
What is the most likely causative organism?

A 63-year-old man presents to the emergency department with productive cough, fever, chills, and intermittent shortness of breath for few days. On examination, there is dullness to percussion and decreased breath sounds over the lower half of the right chest. The X-ray reveals consolidation in the right middle and lower lobes, along with moderate pleural effusion.
Which one of the following is the most appropriate next step in management?

A 46-year-old woman with chronic hepatitis B virus infection presents with jaundice and bilateral lower limb edema. Laboratory investigations reveal elevated AST and ALT levels with high HBV DNA viral load. Abdominal ultrasound demonstrates micro-fibrotic changes in the liver.
Which one of the following is the most appropriate next step in management?

A 24-year-old man presents with two-week history of watery diarrhea, which began one week after returning from India. He reports no fever, bloody stools, or abdominal pain. On examination, he appears well-hydrated with normal vital signs. Stool microscopy shows no leukocytes, erythrocytes, or parasites.
Which one of the following is the most likely causative organism?

A 54-year-old man with HIV presents to the clinic. He reports 8-week history of dry cough that progressed to green sputum production over the past 3 days. Associated symptoms include dyspnea on exertion, unintentional 5-kg weight loss, and night sweats. A chest radiograph shows thick-walled cavitary lesion with air-fluid level in the right upper lobe.
Which of the following infection control precautions is most appropriate for this patient?

A 24-year-old nurse experiences percutaneous injury from suture needle on patient with known cirrhosis and positive hepatitis B surface antigen. The nurse’s health record shows B vaccination series 10 years ago, with no further details available.
What is the most appropriate action to minimize her risk of hepatitis B infection?

A 34-year-old man presents to the emergency department with pain in his right knee. His medical history is unremarkable. Physical examination reveals marked effusion, warmth, and limited range of motion. An arthrocentesis demonstrates yellow and turbid fluid. Synovial analysis shows white blood cell count of 15,000/mm³ with 90% polymorphonuclear neutrophils. Mucin clot test is positive.
Based on the findings, what is the most likely diagnosis?

A young patient presents to the clinic with abdominal pain. On physical examination, there is tenderness and palpable mass on right upper quadrant. Imaging reveals approximately 12 × 14 cm liver abscess with septations. Stool microscopy confirms Entamoeba histolytica infection.
What is the initial next step in management?

A 50-year-old male construction worker presents to the clinic with progressive shortness of breath and cough over the past few years. Recently, he has developed fever, night sweats, and unintentional weight loss of 5 kg.
Which of the following is the most likely risk factor for the development of tuberculosis in this patient?