E.G., a 39-year-old archaeologist and university professor, returned from a 6-month expedition in the rain forest of South America suffering from a combination of physical symptoms and conditions that would not subside on their own. He was fatigued, yet unable to sleep through the night. He also had a mild fever, night sweats, occasional dizziness, double vision, and mild crampy abdominal pain accompanied by intermittent diarrhea. In addition, he had a nonhealing wound on his ankle from an insect bite. He made an appointment with his family doctor, an internist.

On examination, E.G. was febrile (feverish) with a temperature of 101°F. His heart and lungs were normal, with a slightly elevated heart rate. His abdomen was tender to palpation (touch), and his bowel sounds were active and gurgling to auscultation (listening with a stethoscope). His skin was dry and warm. He had symmetrical areas of edema (swelling) around both knees and tenderness over both patellae (kneecaps). The ulceration on his left lateral ankle had a ring of necrosis (tissue death) surrounding an area of granulation tissue. There was a small amount of purulent (pus-containing) drainage.

E.G.’s doctor ordered a series of hematology lab studies and stool cultures for ova and parasites. The doctor suspected a viral disease, possibly carried by mosquitoes, indigenous to tropical rain forests. He also suspected a form of dysentery typically caused by protozoa. E.G. was also possibly anemic, dehydrated, and septic (infected). The doctor was confident that after definitive diagnosis and treatment, E.G. would gain relief from his insomnia, diplopia (double vision), and dizziness.

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