Consider the following medical report that includes the patient's historical health records. Use it to predict the disease that the patient is high likely exposed to. 

 Medical Report: past medical history: 1. known aortic stenosis as previously described. 2. benign prostatic hypertrophy. 3. hypertension. 4. diverticulosis. 5. status post colectomy. 6. status post cholecystectomy. 7. status post hernia repair. 8. status post craniotomy. medications on admission: 1. hydrochlorothiazide 25 mg p.o.q.d. 2. atenolol 25 mg p.o.q.d. 3. k-dur 8 meq p.o.q.d. allergies: the patient states no known drug allergies. physical examination: examination, preoperatively, is unremarkable. hospital course: the patient was admitted on the day of surgery and taken to the operating room on , where he underwent an aortic valve replacement with a 21-mm pericardial prosthetic valve by dr. . postoperatively, the patient was transported from the operating room to the cardiac surgery recovery unit later in the day of surgery. he was weaned from mechanical ventilation and extubated successfully without any sequela from that. he was on nitroglycerin iv drip, as well as an insulin iv drip, which were both weaned off by the following morning. on postoperative day #1, the patient remained hemodynamically stable. chest tubes were removed, and he was transferred to the telemetry floor. on postoperative day #2, the patient began ambulation, physical therapy and progressed to a level 3 to 4 cardiac rehabilitation status on postoperative day #2. he had remained hemodynamically stable throughout his postoperative course. on postoperative day #2, the patient's epicardial pacing wires were removed. the patient had a questionable episode of a scant amount of sternal drainage on postoperative day #2, however, it was seen to be an isolated event and he has had no further sternal drainage. he was placed on vancomycin for this for approximately twenty-four hours. on postoperative day #3, , the patient remains hemodynamically stable and he is anxious to go home. he has progressed to physical therapy level 5 ambulation and he will be discharged home this evening on postoperative day #3. condition on discharge: temperature: 99.3; heart rate 90 normal sinus rhythm; blood pressure 122/66; oxygen saturation 95% on two liters nasal cannula. coronary examination revealed regular rate and rhythm. breath sounds are clear and equal bilateral. his wound is without any drainage or erythema on the sternal incision. discharge medications: 1. lopressor 50 mg p.o.b.i.d. 2. captopril 6.25 mg p.o.t.i.d. 3. lasix 20 mg p.o.b.i.d. times 7 days. 4. potassium chloride 20 meq p.o.b.i.d. times 7 days. 5. colace 100 mg p.o.b.i.d. 6. enteric coated aspirin 325 mg p.o.q.d. 7. percocet 5/325, one to two tablets p.o.q.4h. to 6h. p.r.n.pain. 8. ibuprofen 400 mg p.o.q6h.p.r.n. pain. discharge diagnosis: aortic stenosis status post aortic valve replacement with a 21-mm pericardial valve. fop care: the patient is to followup with dr. in approximately four weeks, as well as to followup with his primary care physician, . in three to four weeks or sooner if needed. condition on discharge: stable. , m.d. dictated by: medquist36 procedure: extracorporeal circulation auxiliary to open heart surgery open and other replacement of aortic valve diagnoses: coronary atherosclerosis of native coronary artery congestive heart failure, unspecified unspecified essential hypertension aortic valve disorders 

Answer: The patient is high likely exposed to