Viruses — MCQs

During an experiment, the immunophenotypes of different cells in a sample are determined. The cells are labeled with fluorescent antibodies specific to surface proteins, and a laser is then focused on the samples. The intensity of fluorescence created by the laser beam is then plotted on a scatter plot. The result shows most of the cells in the sample to be positive for CD8 surface protein. Which of the following cell types is most likely represented in this sample?

A 9-year-old male presents to your office with an indurated rash on his face. You diagnose erythema infectiosum. Which of the following is characteristic of the virus causing this patient's disease?

If the genetic material were isolated and injected into the cytoplasm of a human cell, which of the following would produce viable, infectious virions?

A previously healthy 7-month-old boy presents with fever, chills, cough, runny nose, and watery eyes. He has a blood pressure of 95/60 mm Hg, heart rate of 130/min, and respiratory rate of 28/min. Physical examination reveals clear lung sounds bilaterally. His mother reports that his brother has been having similar symptoms. A nasal swab is obtained, and he is diagnosed with influenza. Assuming that this is the child's first exposure to the influenza virus, which of the following immune mechanisms will most likely function to combat the viral infection?

A 23-year-old man is evaluated as a potential kidney donor for his father. His medical history is significant only for mild recurrent infections as a child. He subsequently undergoes a donor nephrectomy that is complicated by unexpected blood loss. During resuscitation, he is transfused with 4 units of O negative packed red blood cells. Shortly after the transfusion begins, he develops generalized pruritus. His temperature is 37.2°C (98.9°F), pulse is 144/min, respirations are 24/min, and blood pressure is 80/64 mm Hg. Physical examination shows expiratory wheezing in all lung fields and multiple pink, edematous wheals over the trunk and neck. His hemoglobin concentration is 8 g/dL. Serum studies show a haptoglobin concentration of 78 mg/dL (N = 30–200) and lactate dehydrogenase level of 180 U/L. This patient's underlying condition is most likely due to which of the following?

A 24-year-old college student presents to student health with 2 days of developing a sore throat, runny nose, and a cough that started today. He states that he has been getting mild fevers which began yesterday. On exam, his temperature is 102.0°F (38.9°C), blood pressure is 135/76 mmHg, pulse is 95/min, and respirations are 12/min. His physician recommends over-the-counter cold medications and reassures him that his symptoms are due to a viral infection that is self-limited. Which of the following best describes the most likely cause of his illness?

A 26-year-old woman seeks evaluation at an urgent care clinic with complaints of fever and generalized muscle and joint pain for the past 3 days. She also complains of nausea, but denies vomiting. She does not mention any past similar episodes. Her past medical history is unremarkable, but she returned to the United States 1 week ago after spending 2 weeks in southeast Asia doing charity work. She received all the recommended vaccines prior to traveling. The temperature is 40.0°C (104.0°F), the respirations are 15/min, the pulse is 107/min, and the blood pressure is 98/78 mm Hg. Physical examination shows mild gingival bleeding and a petechial rash over the trunk. Laboratory studies show the following: Laboratory test Leukocyte count 4,000/mm³ Platelet count 100,000/mm³ Partial thromboplastin time (activated) 45 seconds Which of the following is the most likely cause of this patient’s condition?

A 35-year-old woman presents to her family physician with a complaint of painful joints for the past 2 weeks. She reports symmetric bilateral joint pain in her hands, knees, and ankles. She has never had this before, and her past medical history is notable only for asthma. She states the pain is worse in the morning and improves throughout the day. Review of systems is notable for a recent low-grade fever with malaise. She works as a school teacher and is sexually active with men and women. Her temperature is 97.9°F (36.6°C), blood pressure is 120/84 mmHg, pulse is 70/min, respirations are 14/min, and oxygen saturation is 97% on room air. The patient is instructed to take ibuprofen and acetaminophen for her joint pain. She returns 1 month later stating that she has not needed to take the medications as her pain has been absent for the past 3 days. Which of the following is the most likely diagnosis?

A 5-year-old boy is brought by his mother to the emergency department with fever, sore throat, runny nose, and rash. The patient’s mother says that symptoms started 3 days ago and that the rash first appeared on his face before spreading. His past medical history is unremarkable. The patient’s family recently moved from Japan to the USA so that the patient's father could work in a famous sushi restaurant in New York. The boy’s vaccination history is not up to date according to US guidelines. His temperature is 38.3°C (101.0°F). On physical examination, there is a maculopapular rash present on the trunk and extremities. There is also significant bilateral cervical lymphadenopathy and small petechial spots on the soft palate. Symptomatic treatment is provided and the patient recovers in 3 days. Which of the following best describes the most likely causative agent responsible for this patient’s condition?

A 34-year-old man presents to an outpatient clinic with chronic fatigue and bumps on his neck, right axilla, and groin. Upon questioning, he reveals he frequently visits Japan on business and is rather promiscuous on his business trips. He denies use of barrier protection. On examination, there is generalized lymphadenopathy. Routine lab work reveals abnormal lymphocytes on peripheral smear. The serum calcium is 12.2 mg/dL. Which of the following viruses is associated with this patient’s condition?