Internal-Medicine

Answers: 9–27 219
their name because they multiply in the GI
tract. Fever, sometimes associated with respiratory
symptoms, is the most common sequela
of enterovirus infection. There are about 70
enteroviruses that affect humans. These include
polioviruses, coxsackieviruses, echoviruses,
and others. The spectrum of disease includes
paralytic disease, encephalitis, aseptic meningitis,
pleurodynia, exanthems, pericarditis,
myocarditis, and nonspecific febrile illnesses.
They can on occasion cause fulminant disease
in a newborn. The most important enteroviruses
are the three poliovirus serotypes. (Kasper,
p. 1144)
19. (A) The incubation period of C. botulinum toxin
is 18–36 hours but ranges from a few hours to
days. There are no sensory symptoms.
Foodborne botulinum is associated primarily
with home-canned food. Severe foodborne botulinum
can produce diplopia, dysarthria, and
dysphagia; weakness then can progress rapidly
to involve the neck, arms, thorax, and legs.
There is usually no fever. Nausea, vomiting,
and abdominal pain can precede the paralysis
or come afterward. (Kasper, p. 842)
20. (D) Heterophil antibody-negative mononucleosis
syndrome is the most common manifestation
of CMV infection in immunocompetent
adults and is more common than the similar
syndrome caused by toxoplasmosis. As of yet,
no syndromes caused by HHV-7 have been
identified in adults. (Kasper, p. 1050)
21. (E) Coccidioidomycosis is the usual cause of
pulmonary cavitation resulting from fungal
infection. A rarefaction may be demonstrable in
a pneumonic lesion within 10 days of onset.
In the United States, most cases are acquired in
California, Arizona, and western Texas. (Kasper,
p. 1181)
22. (C) The most common complication of measles
is otitis media, other complications include
mastoiditis, pneumonia, bronchitis, encephalitis,
and lymphadenitis. Otitis media is usually
a bacterial superinfection, and should be
treated with antibiotics. (Kasper, p. 1149)
23. (D) Subacute sclerosing panencephalitis causes
involuntary spasmodic movements and progressive
mental deterioration, frequently
ending in death within a year. It usually occurs
in children whose measles occurred at an early
age (= 2 years). It occurs 6–8 years after the primary
infection. It presents with nonspecific
symptoms such as poor school performance
or mood and personality changes. It then
progresses to intellectual decline, seizures,
myoclonus, ataxia, and visual disturbances.
Continued deterioration results in inevitable
death. (Kasper, p. 1150)
24. (E) Demonstration of hematophagous trophozoites
of E. histolytica in stool confirms the diagnosis.
The trophozoites are rapidly killed by
drying, so wet mounts of stool should be examined.
(Kasper, p. 1216)
25. (B) Since the introduction of H. influenzae type
B vaccine, S. pneumoniae has become the most
common type of meningitis in infants and toddlers.
(Kasper, p. 810)
26. (D) Pregnancy or anticipated pregnancy within
4 weeks of vaccination is a contraindication to
receiving the rubella vaccine. There is a theoretical
concern that fetus might develop congenital
rubella syndrome from the live attenuated
virus used for the vaccine. Vaccination is usually
given to children combined with measles
and mumps vaccine between 12 and 15 months
of age, and then repeated during childhood at
age 4–6 years. It is given even to children with
HIV infection. Infants