Internal-Medicine

Questions: 48–57 209
53. A 19-year-old woman was traveling in a rural
area of South America. She returned 3 weeks
ago and, over the past few days, has gradually
developed lower abdominal pain and diarrhea.
Now the symptoms are much worse with
10 stools a day consisting mostly of mucus and
blood. She is afebrile, the abdomen is tender in
left lower quadrant, and the remaining examination
is normal. Her stool is mostly comprised
of blood and mucus. Which of the following is
the most likely causative organism?
(A)
(B)
(C)
(D)
(E)
Escherichia coli infection
Salmonella infection
Shigella infection
Vibrio parahaemolyticus infection
E. histolytica infection
54. An 18-year-old man develops fever, neck stiffness,
and headache. On examination, his blood
pressure is 110/80 mm Hg, pulse 100/min,
temperature 38.7°C, and neck flexion is very
painful. The ears, throat, and sinuses are
normal; there are no focal neurologic signs; and
the remaining examination is normal. There
are no reported similar cases in the community.
Which of the following is the most likely
causative organism?
(A)
(B)
(C)
(D)
(E)
Neisseria meningitides
Streptococcus pneumoniae
Haemophilus influenzae
Staphylococcus
Listeria species
55. A 21-year-old man presents with symptoms of
headache, fever, chills, and discomfort in both
sides of his jaw. He has also noticed discomfort
in his testes, but no dysuria or urethral discharge.
Physical examination reveals bilateral
enlargement of the parotid glands, as well as
bilateral testicular enlargement and tenderness
on palpation. His temperature is 38.5°C pulse
rate of 92/min, and the remaining examination
is normal. Laboratory data show hemoglobin
15 g/dL; hematocrit 40%; WBC
12000/mL, with 30% segmented neutrophils,
8% monocytes, and 62% lymphocytes. Which
of the following statements concerning this disease
is true?
(A) the disease is caused by a herpesvirus
(B) the incubation period is 3–5 days
(C) the most common complication of this
disease in postpubertal boys and men is
orchitis
(D) recurrent infections may occur
(E) an increased serum amylase is proof of
the existence of pancreatitis as a
complication
56. A 43-year-old businesswoman is developing a
new enterprise in Mexico. On her most recent
trip, she developed diffuse watery diarrhea
with severe cramps 1 week after arriving. The
illness resolved after about 2 days with no further
complications. Which of the following is
the most likely causative organism?
(A)
(B)
(C)
(D)
(E)
Campylobacter
E. coli
Salmonella
Shigella
rotavirus
57. A 22-year-old man is an avid spelunker (cave
explorer) and has recently been exploring several
caves. A routine CXR taken for a new job
reveals hilar adenopathy and two patches of
pneumonitis. His physical examination is completely
normal. Careful questioning reveals he
has just gotten over a “cold” with mild fever,
cough, and malaise. Which of the following is
the most likely diagnosis?
(A)
(B)
(C)
(D)
(E)
tuberculosis (TB)
sarcoidosis
candidiasis
histoplasmosis
coccidioidomycosis