Viruses — MCQs

The surgical equipment used during a craniectomy is sterilized using pressurized steam at 121°C for 15 minutes. Reuse of these instruments can cause transmission of which of the following pathogens?

A 2-year-old boy presents to the pediatrician for evaluation of an elevated temperature, sore throat, runny nose, and lacrimation for the past week, and a rash which he developed yesterday. The rash began on the patient’s face and spread down to the trunk, hands, and feet. The patient’s mother gave him ibuprofen to control the fever. The child has not received mumps, measles, and rubella vaccinations because he was ill when the vaccine was scheduled and was later lost to follow-up. The vital signs include blood pressure 90/50 mm Hg, heart rate 110/min, respiratory rate 22/min, and temperature 37.8°C (100.0℉). On physical examination, the child was drowsy. His face, trunk, and extremities were covered with a maculopapular erythematous rash. Two irregularly-shaped red dots were also noted on the mucosa of the lower lip. The remainder of the physical examination was within normal limits. What is the probable causative agent for this child’s condition?

Researchers are investigating a new strain of a virus that has been infecting children over the past season and causing dermatitis. They have isolated the virus and have run a number of tests to determine its structure and characteristics. They have found that this new virus has an outer coating that is high in phospholipids. Protein targeting assays and immunofluorescence images have shown that the outer layer contains numerous surface proteins. On microscopy, these surface proteins are also expressed around the nucleus of cells derived from the infected tissue of the children. This virus’s structure most closely resembles which of the following?

A 45-year-old man presents to the emergency room with cough, dyspnea, and fever over the past 2 days. He also has substernal chest pain that worsens with inspiration. He recently recovered from a mild upper respiratory infection. His past medical history is notable for gout, hypertension, major depressive disorder, obesity, diabetes mellitus, and non-alcoholic fatty liver disease. He takes allopurinol, lisinopril, buproprion, and metformin. He works as a policeman and has a 25-pack-year smoking history. His temperature is 100.8°F (38.2°C), blood pressure is 150/75 mmHg, pulse is 108/min, and respirations are 22/min. On examination, he appears to be in mild distress but is cooperative and appropriately interactive. When the patient leans forward, a friction rub can be heard at the left lower sternal border. A basic metabolic panel is within normal limits. This patient’s condition is most likely caused by which of the following types of pathogens?

A 3-year-old boy presents with his mother to the family medicine clinic for an itchy rash on the face that started 3 days ago. The mother states that her son had a fever with a runny nose a little more than a week ago. There has been no sore throat or cough according to the mother. No significant medical conditions are noted. No medications are on record. The boy is up-to-date on all immunizations. His heart rate is 102/min, respiratory rate is 24/min, temperature is 36.5°C (97.7°F), and blood pressure is 92/65 mm Hg. The boy appears well-nourished and alert. Auscultation of the heart is without murmurs. Lungs are clear to auscultation bilaterally. An erythematous malar rash extending from the left lateral nasal region to the left medial zygomatic region is present. There is no lymphadenopathy present. A full skin examination reveals an erythematous, reticulated rash on the lower extremities (see image). Which of the following etiologic agents is responsible for the patient's signs and symptoms?

A 12-year-old girl presents to her physician for the evaluation of episodic shortness of breath and cough. These episodes occur more frequently in spring. Her mother has a history of similar complaints. The physical examination reveals bilateral wheezes on chest auscultation. The initial response to pollen consists of the production of IgM; however, over time, antigen-specific IgE becomes predominant. This change from an IgM to an IgE response is caused by which of the following processes?

A 19-year-old male college student presents to the clinic in the month of January with a 2-day history of watery diarrhea. The patient also complains of weakness, nausea, vomiting and abdominal cramps. He has no significant past medical history. He does not take any medication. He drinks socially on the weekends but does not smoke cigarettes. He recently returned from a cruise with his fraternity brothers. Blood pressure is 110/70 mm Hg, heart rate is 104/min, respiratory rate is 12/min and temperature is 37.7°C (99.9°F). On physical examination his buccal mucosa is dry. The physician suggests oral rehydration therapy. Which of the following is the most likely causative agent?

An investigator studying viral replication isolates the genetic material of an unidentified virus strain. After exposing a cell culture to the isolated, purified viral genetic material, the cells begin to produce viral polymerase and subsequently replicate the viral genome. Infection with the investigated strain is most likely to cause which of the following conditions?

A 3-year-old boy is brought to the pediatrician by his parents with a presentation of severe diarrhea, vomiting, and fever for the past 2 days. The child is enrolled at a daycare where several other children have had similar symptoms in the past week. On physical exam, the child is noted to have dry mucous membranes. His temperature is 102°F (39°C). Questions regarding previous medical history reveal that the child’s parents pursued vaccine exemption to opt out of most routine vaccinations for their child. The RNA virus that is most likely causing this child’s condition has which of the following structural features?

A virology student is asked to identify a sample of virus. When subjected to a nonionic detergent, which disrupts lipid membranes, the virus was shown to lose infectivity. The student then purified the genetic material from the virus and subjected it to treatment with RNase, an enzyme that cleaves the phosphodiester linkages in the RNA backbone. A minute amount of the sample was then injected into a human cell line and was found to produce viral particles a few days later. Which of the following viruses was in the unknown sample?