Internal-Medicine

202 10: Infection
14. A 56-year-old man is having intermittent fevers
and malaise for the past 2 weeks. He has no
other localizing symptoms. Two months ago,
he had valve replacement surgery for a bicuspid
aortic valve. Amechanical valve was inserted
and his postoperative course was uncomplicated.
On examination, his temperature is 38°C,
blood pressure 124/80 mm Hg, pulse 72/min,
and head and neck are normal. There is a 3/6
systolic ejection murmur, the second heart
sound is mechanical, and a 2/6 early diastolic
murmur is heard. The lungs are clear and the
skin examination is normal. Three sets of blood
cultures are drawn and an urgent echocardiogram
is ordered. Which of the following is the
most likely causative organism?
(A)
(B)
(C)
(D)
(E)
Staphylococcus aureus
S. epidermidis
S. viridans
enterococci
Candida
15. Two students from a university dormitory
building have contracted meningitis due to
Neisseria meningitides. Which of the following
students in the dormitory are most likely to
benefit from chemoprophylaxis?
(A)
(B)
(C)
(D)
(E)
everybody in the dormitory, with oral
amoxicillin
close contacts only, with oral amoxicillin
everybody in the dormitory, with oral
rifampin
close contacts only, with oral rifampin
everybody in the dormitory, with
meningococcal vaccine
16. A 21-year-old woman visits her physician
because of 3 weeks of a “flu-like” illness. She
reports symptoms of malaise, fever, fatigue, and
a sore throat. There is no weight loss or night
sweats, and she has not traveled out of country.
Her past medical history is not significant and
she is not taking any medications. Physical
examination is normal except for enlarged cervical
lymph nodes. Laboratory data show
hemoglobin 13.2 g/dL; hematocrit 42%;
platelets 380,000/mL; WBC 8500/mL, with
35% segmented neutrophils, 1% eosinophils,
and 64% lymphocytes, of which 36% were
atypical. A heterophil antibody (sheep cell
agglutination) test is negative. Which of the
following is the most likely causative organism?
(A)
(B)
(C)
(D)
(E)
herpes simplex
echovirus
CMV
coxsackievirus
reovirus
17. A 23-year-old woman visits your office because
of headache, malaise, anorexia, pain in both
sides of her jaw, and discomfort in both lower
abdominal quadrants. Physical examination
reveals enlarged parotid glands; bilateral lower
quadrant abdominal tenderness; a temperature
of 38.7°C; and a pulse rate of 92/min. Serologic
testing (IgM) confirms the diagnosis of mumps.
Which of the following is the most appropriate
treatment for this condition?
(A)
(B)
(C)
(D)
(E)
symptomatic
immunization
broad-spectrum antibiotics
sulfonamides
steroids
18. A 10-year-old boy presents with fever,
headache, photophobia, and neck discomfort in
the middle of summer. He is alert and oriented,
but has neck pain with flexion and extension of
the head. His fundi are normal, and there are
no focal neurologic findings or skin changes. A
lumbar puncture reveals normal protein and
glucose with a cell count of 240/mL (90% lymphocytes).
Which of the following is the most
likely causative organism?
(A)
(B)
(C)
(D)
(E)
enterovirus (coxsackievirus or
echovirus)
Streptococcus pneumoniae
Neisseria meningitides
Listeria monocytogenes
HSV-1
19. An 18-year-old woman has eaten homemade
preserves. Eighteen hours later, she develops
diplopia, dysarthria, and dysphagia. Which of