muscle weakness over several weeks. He has also experienced
nausea, vomiting, and diarrhea. One month ago he
had been completely healthy and describes a bear hunting
trip in Alaska, where they ate some of the game they
killed. Soon after he returned, his gastrointestinal (GI)
symptoms began, followed by muscle weakness in his jaw
and neck that has now spread to his arms and lower back.
Examination confirms decreased muscle strength in the
upper extremities and neck. He also has slowed extraocular
movements. Laboratory examination shows panic
values for elevated eosinophils and serum creatine phosphokinase.
Which of the following organisms is most
likely the cause of his symptoms?
A. Campylobacter
B. Cytomegalovirus
C. Giardia
D. Taenia solium
E. Trichinella
The answer is Trichenella. Trichinellosis occurs when infected meat products are eaten, most frequently pork. The organism can also be transmitted through the ingestion of meat from dogs, horses, and bears. Recent outbreaks in the United States and Canada
ReplyDeletehave been related to consumption of wild game, particularly bear meat. During the first
week of infection, diarrhea, nausea, and vomiting are prominent features. As the parasites migrate from the GI tract, fever and eosinophilia are often present. Larvae encyst after 2–3 weeks in muscle tissue, leading to myositis and weakness. Myocarditis and
maculopapular rash are less common features of this illness. Giardia and Campylobacter are organisms that are frequently acquired by drinking contaminated water; neither will
produce this pattern of disease. While both will cause GI symptoms (and Campylobacter
will cause fever), neither will cause eosinophilia or myositis. Taenia solium, or pork tapeworm,shares a similar pathogenesis to Trichinella but does not cause myositis. Cytomegalovirus has varied presentations but none that lead to this presentation.