From the Division of General Internal Medicine (Dr Wight); Division of Public Health, Infectious Diseases and Occupational Medicine (Drs Swift, O'Horo, Hainy, Molella, and Breeher, and Ms Morrow); Occupational Health Services (Drs Swift, Hainy, and Breeher); and Division of Pulmonary and Critical Care Medicine (Dr O'Horo), Mayo Clinic, Rochester, Minn.