Hepatitis B/C — MCQs

A 45-year-old immunocompetent woman from rural Ohio presents with a 3-week history of low-grade fever, night sweats, and a non-productive cough. She recently helped clean out an old barn near a dried river bed. Chest CT reveals mediastinal lymphadenopathy and multiple small pulmonary nodules. A bronchoalveolar lavage specimen is sent for fungal culture. At 25°C, the organism grows as a mold with tuberculate macroconidia. At 37°C, the same isolate grows as small yeast cells (2–4 µm) found inside macrophages on cytology. A colleague suggests the presentation is more consistent with Blastomyces dermatitidis based on the geographic exposure. Which of the following findings would most definitively argue against the colleague's proposed organism and confirm the correct diagnosis?

A group of researchers conducted various studies on hepatitis C incidence and prevalence. They noticed that there is a high prevalence of hepatitis C in third-world countries, where it has a significant impact on the quality of life of the infected individual. The research group made several attempts to produce a vaccine that prevents hepatitis C infection but all attempts failed. Which of the following would most likely be the reason for the failure to produce a vaccine?

A 13-year-old boy presents to the pediatrician with yellow discoloration of the sclerae since yesterday, and dark-colored urine for 2 days. A detailed history is taken and reveals that he had a cough, cold, and fever the week before the onset of the current symptoms, and was treated with over-the-counter medications. He reports an improvement in his upper respiratory symptoms but has been experiencing fatigue, nausea, and poor appetite since then. There is no past history of recurrent nausea, vomiting, jaundice or abdominal pain, and he has not received any blood transfusion. In addition, he frequently eats at a roadside restaurant near his school. His growth and development are normal for his age and sex. The temperature is 37.9°C (100.2°F), pulse is 96/min, blood pressure is 110/70 mm Hg, and the respiratory rate is 22/min. The physical examination shows icterus. The examination of the abdomen reveals tender hepatomegaly with the liver having a firm, sharp, and smooth edge. The laboratory test results are as follows: Hemoglobin 14.2 g/dL WBC (white blood cell) 10,500/mm3 Differential leukocyte count Segmented neutrophils 56% Bands 4% Lymphocytes 35% Eosinophils 2% Basophils 0% Monocytes 3% Platelet count 270,000/mm3 Serum total bilirubin 8.4 mg/dL Serum direct bilirubin 7.8 mg/dL Serum alanine aminotransferase 350 U/L Serum alkaline phosphatase 95 U/L Prothrombin time 20 seconds Which of the following laboratory tests is most likely used to diagnose the condition of this patient?

A scientist is studying the replication sequences of a number of different viruses. He observes that one particular virus he is studying creates a single stranded DNA from an RNA template during its replication sequence. Which of the following viruses is he most likely observing?

A previously healthy 25-year-old woman comes to the physician because of a one-week history of diffuse abdominal pain. Her temperature is 39.1°C (102.3°F). Physical examination shows numerous scars and excoriations along both arms, scleral icterus, and tender hepatomegaly. Serum studies show: Alanine aminotransferase 927 U/L Aspartate aminotransferase 796 U/L Hepatitis B surface antigen positive Hepatitis B surface antibody negative Anti-hepatitis B core antibody positive Hepatitis C antibody negative Which of the following is the most likely outcome of this patient's infection?