HCV structure and genotypes — MCQs

A 28-year-old woman with a history of intravenous drug use is brought to the emergency department because of a 1-day history of fatigue, yellow eyes, confusion, and blood in her stools. She appears ill. Her temperature is 38.1°C (100.6°F). Physical examination shows pain in the right upper quadrant, diffuse jaundice with scleral icterus, and bright red blood in the rectal vault. Further evaluation demonstrates virions in her blood, some of which have a partially double-stranded DNA genome while others have a single-stranded RNA genome. They are found to share an identical lipoprotein envelope. This patient is most likely infected with which of the following pathogens?

A scientist in Chicago is studying a new blood test to detect Ab to EBV with increased sensitivity and specificity. So far, her best attempt at creating such an exam reached 82% sensitivity and 88% specificity. She is hoping to increase these numbers by at least 2 percent for each value. After several years of work, she believes that she has actually managed to reach a sensitivity and specificity much greater than what she had originally hoped for. She travels to China to begin testing her newest blood test. She finds 2,000 patients who are willing to participate in her study. Of the 2,000 patients, 1,200 of them are known to be infected with EBV. The scientist tests these 1,200 patients' blood and finds that only 120 of them tested negative with her new exam. Of the patients who are known to be EBV-free, only 20 of them tested positive. Given these results, which of the following correlates with the exam's specificity?

A scientist is researching the long term effects of the hepatitis viruses on hepatic tissue. She finds that certain strains are oncogenic and increase the risk of hepatocellular carcinoma. However, they appear to do so via different mechanisms. Which of the following answer choices correctly pairs the hepatitis virus with the correct oncogenic process?

A 30-year-old woman presents with generalized fatigue, joint pain, and decreased appetite. She says that symptoms onset a year ago and have not improved. The patient’s husband says he has recently noticed that her eyes and skin are yellowish. The patient denies any history of smoking or alcohol use, but she admits to using different kinds of intravenous illicit drugs during her college years. The patient is afebrile and vital signs are within normal limits. Physical examination is unremarkable, except for moderate scleral icterus. A polymerase chain reaction (PCR) of a blood sample is positive for a viral infection that reveals a positive-sense RNA virus, that is small, enveloped, and single-stranded. The patient is started on a drug that resembles a purine RNA nucleotide. She agrees not to get pregnant before or during the use of this medication. Which of the following is the drug that was most likely given to this patient?

An investigator is studying the rate of multiplication of hepatitis C virus in hepatocytes. The viral genomic material is isolated, enzymatically cleaved into smaller fragments and then separated on a formaldehyde agarose gel membrane. Targeted probes are then applied to the gel and visualized under x-ray. Which of the following is the most likely structure being identified by this test?

A 23-year-old male with a homozygous CCR5 mutation is found to be immune to HIV infection. The patient’s CCR5 mutation interferes with the function of which viral protein?

A 52-year-old man presents to his physician after his routine screening revealed that he has elevated liver enzymes. He complains of occasional headaches during the past year, but otherwise feels well. The patient reports that he was involved in a serious car accident in the 1980s. He does not smoke or drink alcohol. He has no history of illicit intravenous drug use. He does not currently take any medications and has no known allergies. His father had a history of alcoholism and died of liver cancer. The patient appears thin. His temperature is 37.8°C (100°F), pulse is 100/min, and blood pressure is 110/70 mm Hg. The physical examination reveals no abnormalities. The laboratory test results show the following: Complete blood count Hemoglobin 14 g/dL Leukocyte count 10,000/mm3 Platelet count 146,000/mm3 Comprehensive metabolic profile Glucose 150 mg/dL Albumin 3.2 g/dL Total bilirubin 1.5 mg/dL Alkaline phosphatase 75 IU/L AST 95 IU/L ALT 73 IU/L Other lab tests HIV negative Hepatitis B surface antigen negative Hepatitis C antibody positive HCV RNA positive HCV genotype 1 A liver biopsy is performed and shows mononuclear infiltrates localized to portal tracts that reveal periportal hepatocyte necrosis. Which of the following is the most appropriate next step in management?

A 45-year-old man presents for follow-up to monitor his chronic hepatitis C treatment. The patient was infected with hepatitis C genotype 1, one year ago. He has been managed on a combination of pegylated interferon-alpha and ribavirin, but a sustained viral response has not been achieved. Past medical history is significant for non-alcoholic fatty liver disease for the last 5 years. Which of the following, if added to the patient’s current treatment regimen, would most likely benefit this patient?

A 53-year-old man presents to an urgent care center with severe fever that began during the day along with muscle and joint pains. He states that he felt fine the day before but then developed a fever to 103°F (39.4°C) and had to leave work after which he developed a headache and body pains. The patient states that he was recently in South Asia for a business trip and was otherwise feeling well since returning 2 weeks ago. On exam, the patient’s temperature is 103.3°F (39.6°C), blood pressure is 110/84 mmHg, pulse is 94/min, and respirations are 14/min. On physical exam, the patient appears flushed and has a rash that blanches when touched. On laboratory workup, the pathogen was identified as an enveloped virus with an icosahedral capsid and had positive-sense, single-stranded linear RNA. Which of the following is the most likely cause of this patient's presentation?

An investigator is studying the mechanism of HIV infection in cells obtained from a human donor. The effect of a drug that impairs viral fusion and entry is being evaluated. This drug acts on a protein that is cleaved off of a larger glycosylated protein in the endoplasmic reticulum of the host cell. The protein that is affected by the drug is most likely encoded by which of the following genes?