When the Fever Breaks

A 24-year-old woman presents to the emergency department in San Juan, Puerto Rico, on illness day 5 after abrupt onset of high fevers, severe myalgias, retro-orbital headache, nausea, and diffuse fatigue. Several coworkers have recently had similar febrile illnesses during the rainy season. She has no major medical history and is not pregnant.

She reports that her fever seemed to improve this morning, but over the last several hours she has developed worsening abdominal pain, repeated vomiting, and increasing lightheadedness. On examination, temperature is 37.4 C, heart rate 114/min, blood pressure 102/90 mmHg, respiratory rate 20/min, and oxygen saturation 99% on room air. She appears tired but arousable. There are scattered petechiae over the forearms and mild right upper quadrant tenderness without guarding.

Laboratory testing shows white blood cells 2.6 x 10^3/uL, hemoglobin 15.8 g/dL, hematocrit 48% (up from 40% the day before at an urgent care visit), platelets 54 x 10^3/uL, AST 142 U/L, and ALT 96 U/L. A malaria smear is negative.