The 68-year-old patient is admitted after 5 days of extremely foul-smelling watery diarrhea with a temperature of 37.9°C, heart rate 118 bpm, and blood pressure 98/52 mmHg. The patient’s recent medical history is significant for being treated 2 weeks ago for a diverticulitis flare-up. Upon assessment, the patient is pale, diaphoretic, and has a tense, distended abdomen that he does not guard with palpation. Lab studies reveal an elevated creatinine (1.9 mg/dL), high white blood cell count (20,000 cells/mL), and normal hemoglobin and hematocrit. Which intervention is most important to prevent the spread of this condition to other patients?