Barkley Infectious Disease Practice
Exam 200 Original Practice Questions
with Detailed Rationales
Section I: Bacterial Infections
1. A nurse accidentally sticks herself with a needle used on a patient
with non-A, non-B hepatitis. She received her hepatitis B vaccine 2
years ago. Her next step would be to:
A. Begin post-exposure prophylaxis
B. Draw baseline labs for herself and the patient
C. Administer hepatitis B immune globulin
D. No action is needed
Correct Answer: B
Rationale: Following a needlestick injury, the first step is to draw
baseline labs from both the healthcare worker and the source
patient to establish baseline serology. Post-exposure prophylaxis
decisions are based on these results. Since the source patient has
non-A, non-B hepatitis (likely hepatitis C), the healthcare worker's
hepatitis B vaccination status does not provide protection against
hepatitis C.
,2. Which of the following populations is most strongly considered at
risk for hepatitis A?
A. Intravenous drug users
B. Men who have sex with men
C. Healthcare workers
D. Dialysis patients
Correct Answer: B
Rationale: Hepatitis A is transmitted via the fecal-oral route. Men
who have sex with men are at increased risk due to sexual practices
that may involve oral-anal contact. Other risk groups include
travelers to endemic areas, individuals experiencing homelessness,
and people who use illicit drugs.
3. What is the most common means of transmission for hepatitis C?
A. Sexual contact
B. IV drug use
C. Blood transfusion
D. Perinatal transmission
Correct Answer: B
Rationale: Hepatitis C is most commonly transmitted through
percutaneous exposure, particularly sharing needles among
intravenous drug users. Since the introduction of blood screening in
1992, transfusion-related transmission has become rare.
4. A patient presents with fever, cough, and green sputum. Chest X-
ray shows right lower lobe consolidation. What is the most likely
,pathogen?
A. Mycoplasma pneumoniae
B. Streptococcus pneumoniae
C. Chlamydia pneumoniae
D. Legionella pneumophila
Correct Answer: B
Rationale: Streptococcus pneumoniae is the most common cause of
community-acquired pneumonia, typically presenting with fever,
productive cough, and lobar consolidation.
5. Which of the following is the most common cause of bacterial
meningitis in adults?
A. Neisseria meningitidis
B. Streptococcus pneumoniae
C. Haemophilus influenzae
D. Listeria monocytogenes
Correct Answer: B
Rationale: Streptococcus pneumoniae is the most common cause of
bacterial meningitis in adults. Neisseria meningitidis is more
common in adolescents and young adults, while Listeria is more
common in neonates and older adults.
6. A patient presents with a painful bump with a small, red-looking
halo on the penis. The affected area is about 5 mm in diameter, soft,
and tender. He states the halo has been there for about a week.
What is the most likely diagnosis?
, A. Syphilis
B. Chancroid
C. Herpes simplex virus
D. Gonorrhea
Correct Answer: B
Rationale: Chancroid is caused by Haemophilus ducreyi and presents
with a painful, soft chancre with a red halo. This is in contrast to
syphilis, which typically presents with a painless, indurated chancre.
7. A 45-year-old with HIV has fever, dry cough, and hypoxemia.
Chest X-ray shows diffuse bilateral interstitial infiltrates. CD4 count
is 50. What is the most likely pathogen?
A. Mycobacterium tuberculosis
B. Pneumocystis jirovecii
C. Cryptococcus neoformans
D. Toxoplasma gondii
Correct Answer: B
Rationale: Pneumocystis jirovecii pneumonia (PCP) typically
presents with fever, dry cough, hypoxemia, and diffuse bilateral
interstitial infiltrates in HIV patients with CD4 <200.
8. A patient has a positive rapid plasma reagin (RPR) test. What is
the next step?
A. Start penicillin
B. Confirm with a treponemal test
Exam 200 Original Practice Questions
with Detailed Rationales
Section I: Bacterial Infections
1. A nurse accidentally sticks herself with a needle used on a patient
with non-A, non-B hepatitis. She received her hepatitis B vaccine 2
years ago. Her next step would be to:
A. Begin post-exposure prophylaxis
B. Draw baseline labs for herself and the patient
C. Administer hepatitis B immune globulin
D. No action is needed
Correct Answer: B
Rationale: Following a needlestick injury, the first step is to draw
baseline labs from both the healthcare worker and the source
patient to establish baseline serology. Post-exposure prophylaxis
decisions are based on these results. Since the source patient has
non-A, non-B hepatitis (likely hepatitis C), the healthcare worker's
hepatitis B vaccination status does not provide protection against
hepatitis C.
,2. Which of the following populations is most strongly considered at
risk for hepatitis A?
A. Intravenous drug users
B. Men who have sex with men
C. Healthcare workers
D. Dialysis patients
Correct Answer: B
Rationale: Hepatitis A is transmitted via the fecal-oral route. Men
who have sex with men are at increased risk due to sexual practices
that may involve oral-anal contact. Other risk groups include
travelers to endemic areas, individuals experiencing homelessness,
and people who use illicit drugs.
3. What is the most common means of transmission for hepatitis C?
A. Sexual contact
B. IV drug use
C. Blood transfusion
D. Perinatal transmission
Correct Answer: B
Rationale: Hepatitis C is most commonly transmitted through
percutaneous exposure, particularly sharing needles among
intravenous drug users. Since the introduction of blood screening in
1992, transfusion-related transmission has become rare.
4. A patient presents with fever, cough, and green sputum. Chest X-
ray shows right lower lobe consolidation. What is the most likely
,pathogen?
A. Mycoplasma pneumoniae
B. Streptococcus pneumoniae
C. Chlamydia pneumoniae
D. Legionella pneumophila
Correct Answer: B
Rationale: Streptococcus pneumoniae is the most common cause of
community-acquired pneumonia, typically presenting with fever,
productive cough, and lobar consolidation.
5. Which of the following is the most common cause of bacterial
meningitis in adults?
A. Neisseria meningitidis
B. Streptococcus pneumoniae
C. Haemophilus influenzae
D. Listeria monocytogenes
Correct Answer: B
Rationale: Streptococcus pneumoniae is the most common cause of
bacterial meningitis in adults. Neisseria meningitidis is more
common in adolescents and young adults, while Listeria is more
common in neonates and older adults.
6. A patient presents with a painful bump with a small, red-looking
halo on the penis. The affected area is about 5 mm in diameter, soft,
and tender. He states the halo has been there for about a week.
What is the most likely diagnosis?
, A. Syphilis
B. Chancroid
C. Herpes simplex virus
D. Gonorrhea
Correct Answer: B
Rationale: Chancroid is caused by Haemophilus ducreyi and presents
with a painful, soft chancre with a red halo. This is in contrast to
syphilis, which typically presents with a painless, indurated chancre.
7. A 45-year-old with HIV has fever, dry cough, and hypoxemia.
Chest X-ray shows diffuse bilateral interstitial infiltrates. CD4 count
is 50. What is the most likely pathogen?
A. Mycobacterium tuberculosis
B. Pneumocystis jirovecii
C. Cryptococcus neoformans
D. Toxoplasma gondii
Correct Answer: B
Rationale: Pneumocystis jirovecii pneumonia (PCP) typically
presents with fever, dry cough, hypoxemia, and diffuse bilateral
interstitial infiltrates in HIV patients with CD4 <200.
8. A patient has a positive rapid plasma reagin (RPR) test. What is
the next step?
A. Start penicillin
B. Confirm with a treponemal test
