Emerging infectious diseases in children — MCQs

A previously healthy 6-year-old boy is brought to the physician because of a 3-day history of progressive rash. The rash started on his face and now involves the entire body. For the past week, he has had a cough and a runny nose. He is visiting from the Philippines with his family. He is in first grade and spends his afternoons at an after-school child care program. Immunization records are not available. His temperature is 39.5°C (103°F), pulse is 115/min, and blood pressure is 105/66 mm Hg. Examination shows generalized lymphadenopathy. There is an erythematous maculopapular, blanching, and partially confluent exanthem on his entire body. The remainder of the examination shows no abnormalities. Which of the following is most likely to confirm the diagnosis?

A 45-year-old male presents to the emergency room complaining of severe nausea and vomiting. He returned from a business trip to Nigeria five days ago. Since then, he has developed progressively worsening fevers, headache, nausea, and vomiting. He has lost his appetite and cannot hold down food or water. He did not receive any vaccinations before traveling. His medical history is notable for alcohol abuse and peptic ulcer disease for which he takes omeprazole regularly. His temperature is 103.0°F (39.4°C), blood pressure is 100/70 mmHg, pulse is 128/min, and respirations are 22/min. Physical examination reveals scleral icterus, hepatomegaly, and tenderness to palpation in the right and left upper quadrants. While in the examination room, he vomits up dark vomitus. The patient is admitted and started on multiple anti-protozoal and anti-bacterial medications. Serology studies are pending; however, the patient dies soon after admission. The virus that likely gave rise to this patient’s condition is part of which of the following families?

A 7-year-old boy is brought to his pediatrician by his parents because of a new rash. The family immigrated from Laos one year ago and recently obtained health insurance. A week ago, the boy stated that he was “not feeling well” and asked to stay home from school. At the time, he starting having cough, nasal congestion, and irritated eyes – symptoms that persisted and intensified. His parents recall that at the time they noticed small whitish-blue papules over the red buccal mucosa opposite his molars. Five days ago, his parents noticed a red rash around his face that quickly spread downward to cover most of his arms, trunk, and then legs. His temperature is 102.5°F (39.2°C), blood pressure is 110/85 mmHg, pulse is 102/min, and respirations 25/min. On physical exam, he has intermittent cough, cervical lymphadenopathy, and nonpurulent conjunctivitis accompanied by a confluent, dark red rash over his body. This patient is at risk for which of the following complications later in life?

A 24-year-old man presents to the emergency department with sudden onset of fever for the past few hours as well as pain and swelling in his right knee and left ankle. He denies any recent history of trauma or injury. The patient is otherwise a healthy, active young man. He recently recovered from a case of gastroenteritis which caused significant abdominal pain and bloody stool 4 weeks ago. He believes the infection was related to eating undercooked chicken while camping. His blood pressure is 124/76 mm Hg, his heart rate is 76/min, and his temperature is 36.9 ℃ (98.4 ℉). Physical examination reveals tenderness to palpation of his right knee and left ankle as well as erythematous conjunctiva. Which of the following features would be least likely to develop in patients with this condition?

A 15-year-old Caucasian male is brought to his pediatrician by his parents, who note the development of a tremor in their child. Urine and serum analysis reveal elevated levels of copper. Which of the following clinical manifestations would the physician most expect to see in this patient?

A 72-year-old man is brought to your office by his daughter due to concern over recent behavioral changes. Over the last several months he has had increasing difficulty with remembering recent events. She mentions that he is embarrassed due to a new inability to control urination. His medical history is significant for hypertension and insomnia. His medications include alprazolam and hydrochlorothiazide. On physical exam, he is oriented to time and place and thinks his daughter is exaggerating; however, when asked to recall 3 items, the patient refuses to continue the mental status exam. He has 5/5 strength bilaterally. He walks in short strides by sliding his feet across the floor. Which of the following would you expect to see in this patient?

A 62-year-old woman comes to the physician because of worsening mental status over the past month. Her husband reports that she was initially experiencing lapses in memory but has recently started having difficulties performing activities of daily living. She appears withdrawn and avoids eye contact. Examination shows diffuse involuntary muscle jerking that can be provoked by loud noises. A cerebrospinal fluid analysis shows elevated concentration of 14-3-3 protein. Four months later, the patient dies. Pathologic examination of the brain on autopsy is most likely to show which of the following findings?

A 13-year-old boy is brought to the emergency department by his parents for severe right hip pain that suddenly started about 2 hours ago. The parents are extremely anxious and feel overwhelmed because the boy has been hospitalized several times in the past for similar episodes of pain. The boy was born at 39 weeks of gestation via spontaneous vaginal delivery. He is up to date on all vaccinations and is meeting all developmental milestones. His only medication is hydroxyurea, which he has been receiving for 3 years. His blood pressure is 125/84 mm Hg, the respirations are 23/min, the pulse is 87/min, and the temperature is 36.7°C (98.0°F). On physical examination, the patient is in distress and has severe pain (8/10) elicited by gentle palpation of the right femoral head. Which of the following conditions has the same pathophysiology as the likely diagnosis for the patient described in this case?

A 7-month-old boy is brought by his parents to the pediatrician’s office. His mother says the child has been weakening progressively and is not as active as he used to be when he was born. His condition seems to be getting worse, especially over the last month. He was born at 41 weeks through normal vaginal delivery. There were no complications observed during the prenatal period. He was progressing well over the 1st few months and achieving the appropriate milestones. On examination, his abdomen appears soft with no liver enlargement. The patient appears to be dehydrated and lethargic. The results of a fundoscopic examination are shown in the picture. A blood test for which of the following enzymes is the next best assay to evaluate this patient's health?

A 7-year-old boy is brought to the physician by his father because of a 1-day history of a pruritic rash on his trunk and face. Five days ago, he developed low-grade fever, nausea, and diarrhea. Physical examination shows a lace-like erythematous rash on the trunk and face with circumoral pallor. The agent most likely causing symptoms in this patient has selective tropism for which of the following cells?