1. Division of Infectious Diseases, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania.
2. Jefferson Medical College of Thomas Jefferson University.
3. Shannon Clinic and Shannon Medical Center, San Angelo, Texas.
4. Wills Eye Institute, Philadelphia, Pennsylvania; and Nemours/AI Dupont Hospital for Children, Wilmington, Delaware.
5. Center for Research in Medical Education and Health Care, Jefferson Medical College, Philadelphia, Pennsylvania.
6. Division of Biostatistics, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania.