Acute pyelonephritis in adults

An otherwise healthy 35-year-old woman presents with urinary urgency, dysuria, fever, malaise, nausea, and flank pain. During a recent trip to India, she took a fluoroquinolone for diarrhea. On examination, the temperature is 38.6°C, the pulse 110 beats per minute, and the blood pressure 105/50 mm Hg; she has suprapubic and flank tenderness, without abdominal tenderness. The white-cell count is 16,500 per cubic millimeter, and the serum creatinine concentration 1.4 mg per deciliter (124 μmol per liter) (most recent measurement before presentation, 0.8 mg per deciliter [71 μmol per liter]). Urinalysis is positive for leukocyte esterase and nitrites.