USMLE CD block 1, #33 - triplehelix

[ArchivalUser]

A 19-year-old college student is brought to the
emergency department by his roommate because
the patient was difficult to arouse in the morning.
He has had a flu-like illness with fever and muscle
and joint aches for 12 hours. His temperature is
39.5EC (103.1EF), pulse is 120/min, and blood
pressure is 90/60 mm Hg. There is a diffuse
petechial rash over the trunk and extremities. He
has a stiff neck that cannot be passively flexed.
Which of the following is the most likely
pathogen?
(A) Coxsackievirus B
(B) Echovirus
© Haemophilus influenzae
(D) Neisseria meningitidis
(E) Streptococcus pneumoniae

[ArchivalUser]

The correct answer is D. The combination of lethargy, fever, and stiff neck suggests acute meningitis. The preceding flulike illness, rapid onset of symptoms, and diffuse petechial rash suggest meningococcal meningitis.
Coxsackievirus B (choice A) causes focal necrosis of skeletal muscle, brain degeneration, and aseptic meningitis.
Echovirus (choice B) causes gastrointestinal tract infection after a prodrome of upper respiratory signs and symptoms, especially in children, and particularly in the summer. It can cause aseptic meningitis with a rash (rubelliform rash), and acute hemorrhagic conjunctivitis. It can progress to myocarditis, encephalitis, and septic shock.
Haemophilus influenzae (choice C) is a good choice in unimmunized infants, but not in a young adult.
It is important to remember that in young, healthy adults, the major pathogens responsible for bacterial meningitis are Streptococcus pneumoniae (choice E) and Neisseria meningitides (choice D).

This is from the released answers for the USMLE CD questions

Ari Vederci

[ArchivalUser]

D.)

[ArchivalUser]

so y not e?

[ArchivalUser]

Here are the released answered to the USMLE CD

http://rapidshare.com/files/26158967/S2_...leased.pdf

Ari Vederci