Table 1. Medical histories and conditions of the index patient and 19 patients affected in the clusters of severe acute respiratory syndrome related to the emergency room (ER) of National Taiwan University Hospital.

Patient no.	Age/sex	Characteristics
Index patient
1	73/M	Coronary artery disease, recent percutaneous occlusive balloon angioplasty and stenting, congestive heart failure, chronic obstructive lung disease, diabetes mellitus, chronic renal insufficiency. Had dyspnea without fever.
First cluster
2	73/M	Infarction, hypertension, diabetes mellitus, old cerebral vascular accident, parkinsonism, hyperthyroidism. Cough for 2 weeks and fever for 1 week and was treated for aspiration pneumonia.
3	24/F	Nursing aid of patient 2.
4	62/F	Hepatitis C virus-related cirrhosis of liver, hypertension, diabetes mellitus. Had upper gastrointestinal bleeding.
5	64/F	Nursing aid of patient 4. Bronchial asthma.
6	65/F	Common bile duct stone and obstructive jaundice status post endoscopic retrograde cholangiopancreatography and endoscopic nasobiliary drainage, gallbladder stone status post cholecystectomy. Had fever and abdominal pain.
Second cluster
7	88/M	Chronic obstructive pulmonary disease, hypertension, coronary artery disease status post percutaneous transluminal coronary angiography. Had lower intestinal bleeding secondary to ischemic colitis.
8	46/F	Family member of patient 9.
9	71/F	Acute pancreatitis, diarrhea.
10	65/F	Coronary artery disease status post percutaneous transluminal coronary angioplasty, major depression, diabetes mellitus, hypertension, end-stage renal disease under regular hemodialysis at a regional hospital. Persistent fever, diarrhea, leukocytosis and normal chest radiograph.
11	63/F	Took care of her son with acute pancreatitis in the ER.
12	38/M	Took care of his mother with end-stage renal disease undergoing hemodialysis. Stayed in the ER for 2 hours on April 29. Fever developed on May 7. Chest radograph was abnormal on May 11.
13	48/F	Nursing aid of a patient with pancreatitis close to acute patient 10 had frequent diarrhea. She helped take care of patient 10.
14	43/F	Nursing aid of patient 10
15	24/F	Nursing aid of a patient who visited the ER on May 2.
16	46/F	Pancreatic cancer with liver metastasis, perforated gastric ulcer status post primary closure and duodenostomy, gastrostomy and jejunostomy, poor control of diabetes mellitus and hypertension, glaucoma. Abdominal pain and watery diarrhea and was diagnosed as adhesion ileus and subcutaneous abscess caused by Klebsiella pneumonia.
17	43/F	Nursing aid. Contact to patient 9. Colon tubular adenoma status post polypectomy, chronic paranasal sinusitis status post functional endoscopic sinus surgery.
18	28/M	Tinea pedis, cellulitis.
19	69/M	Coronary artery disease, status post percutaneous transluminal coronary angioplasty. Abdominal discomfort and loss of appetite for several weeks. Cholangiocarcinoma, obstructive jaundice, biliary tract infection and upper gastrointestinal bleeding were diagnosed.
20	28/F	Nursing aid.