Post-transplant infectionsDownloads

A 26-year-old man comes to the physician for a follow-up examination. He was diagnosed with HIV infection 2 weeks ago. His CD4+ T-lymphocyte count is 162/mm3 (N ≥ 500). An interferon-gamma release assay is negative. Prophylactic treatment against which of the following pathogens is most appropriate at this time?

A 55-year-old woman recently underwent kidney transplantation for end-stage renal disease. Her early postoperative period was uneventful, and her serum creatinine is lowered from 4.3 mg/dL (preoperative) to 2.5 mg/dL. She is immediately started on immunosuppressive therapy. On postoperative day 7, she presents to the emergency department (ED) because of nausea, fever, abdominal pain at the transplant site, malaise, and pedal edema. The vital signs include: pulse 106/min, blood pressure 167/96 mm Hg, respirations 26/min, and temperature 40.0°C (104.0°F). The surgical site shows no signs of infection. Her urine output is 250 mL over the past 24 hours. Laboratory studies show: Hematocrit 33% White blood cell (WBC) count 6700/mm3 Blood urea 44 mg/dL Serum creatinine 3.3 mg/dL Serum sodium 136 mEq/L Serum potassium 5.6 mEq/L An ultrasound of the abdomen shows collection of fluid around the transplanted kidney with moderate hydronephrosis. Which of the following initial actions is the most appropriate?