Read the excerpt from the supporting text "Disease Central" in When Birds Get Flu by John DiConsiglio. In 1958, scientists at the CDC made their first trip overseas. A team went to Southeast Asia to respond to an epidemic of smallpox and cholera.

The author uses this passage to help the reader focus on

why Dr. Dowell is in Thailand.
why epidemics are dangerous.
why scientists work for the CDC.
why the CDC was formed.

An 80-year-old woman comes to the urgent care clinic with dyspnoea on exertion. on physical examination, her blood pressure is 100/70, and her pulse is 75. she has no pulsus paradoxus. her jugular veins are distended, and she has distant heart sounds. in addition, she has extra third and fourth heart sounds. her liver is enlarged, and she has pedal oedema. she has occasional premature ventricular contractions on her electrocardiogram. a chest x-ray reveals clear lung fields with a dilated cardiac silhouette. her echocardiogram reveals ventricular walls with a "speckled pattern". which of the following is the most likely diagnosis? - alcoholic cardiomyopathy- amyloidosis- haemochromatosis- tuberculosis- viral myocarditis